United States
Environmental Protection
Agency
Robert S Kerr Environmental Research
Laboratory
Ada OK 74820
EPA-600/2-78-179
August 1978
Research and Development
&EPA
Land and Water Use
Effects on
Ground-Water Quality
In Las Vegas Valley
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RESEARCH REPORTING SERIES
Research reports of the Office of Research and Development, U.S. Environmental
Protection Agency, have been grouped into nine series. These nine broad cate-
gories were established to facilitate further development and application of en-
vironmental technology. Elimination of traditional grouping was consciously
planned to foster technology transfer and a maximum interface in related fields.
The nine series are:
1. Environmental Health Effects Research
2. Environmental Protection Technology
3. Ecological Research
4. Environmental Monitoring
5. Socioeconomic Environmental Studies
6. Scientific and Technical Assessment Reports (STAR)
7. Interagency Energy-Environment Research and Development
8. "Special" Reports
9. Miscellaneous Reports
This report has been assigned to the ENVIRONMENTAL PROTECTION TECH-
NOLOGY series. This series describes research performed to develop and dem-
onstrate instrumentation, equipment, and methodology to repair or prevent en-
vironmental degradation from point and non-point sources of pollution. This work
provides the new or improved technology required for the control and treatment
of pollution sources to meet environmental quality standards.
This document is available to the public through the National Technical Informa-
tion Service, Springfield, Virginia 22161.
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EPA-600/2-78-179
August 1978
LAND AND WATER USE EFFECTS ON GROUND-WATER QUALITY
IN LAS VEGAS VALLEY
by
Robert F. Kaufmann
Desert Research Institute
Las Vegas, Nevada 89109
Grant No. R800946
Project Officer
Fredric Hoffman
Region IX
San Francisco, California 94111
ROBERT S. KERR ENVIRONMENTAL RESEARCH LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
ADA, OKLAHOMA 74820
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DISCLAIMER
This report has been reviewed by the Robert S. Kerr Environmental
Research Center, U. S. Environmental Protection Agency, and approved for
publication. Approval does not signify that the contents necessarily
reflect the views and policies of the U. S. Environmental Protection Agency,
nor does mention of trade names or commercial products constitute endorse-
ment or recommendation for use.
11
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bfcDICATION
Dr. George B. Maxey, an esteemed scholar1 and true friend, conducted
and guided fundamentally important groundwater studies in southern Nevada
for over three decades. His Knowledge of groundwater occurrence, quality,
and movement and his integration of geologic and hydrologic principles
on local, basin and regional scales continues to permeate the theory and
application of hydrbgeology. In southern Nevada and especially in Las
Vegas Valley, he was an unquestioned authority. His perception of science
and people and his unwavering ability to conceive and implement responsive
research programs are legend. With fespect to the effort presented herein,
he was intimately involvted as a scientist, administrator, and above all,
a cherished colleague whose encouragement, criticism and continual personal
concern will always have my gratitude. His influence can best be fathomed
and appreciated by those who had the pleasure to interact with him in the
subject areas he so dearly loved. He was and is the rare being that one
never forgets.
111
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FOREWORD
Since the vast influx of population began poring into the Las Vegas
Valley in the 1940's the hydrologic regime of the Valley has undergone
significant change. The pristine environment of the Valley was desert with
desert vegetation and no perennial flow out of the Valley. With increase
in population came the proliferation of lawns, shrubs, and trees throughout
the Valley. This domestic irrigation of vegetation together with waste-
water return flows has created a perennial stream leaving the Valley
through Las Vegas Wash. This study was implemented to determine what is
happening in the shallow ground-water zone (0 to 300') within the Valley,
its flow, and the main sources of contamination. Results of this study have
been divided into three volumes, this publication, the first volume, deals
with the problem of how ground-water quality is affected by land and water
use throughout the Valley. Volume two entitled, "Las Vegas Valley Water
Budget: Relationship of Distribution, Consumptive Use, and Recharge to
Shallow Ground Water," gives a detailed picture of the input and outflow
of the water being used in Las Vegas Valley. The third volume, "Simula-
tion Modeling of the Shallow Ground-water System in Las Vegas Valley,"
discusses the problems and water level fluctuations in the shallow ground-
water system.
These three volumes represent an assessment of the shallow ground-water
system in Las Vegas Valley and should be of use to anyone dealing with
that aspect of the hydrologic regime in Las Vegas Valley.
Gilbert F. Cochran
Acting Executive Director
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ABSTRACT
The hydrogeologic study of the shallow ground-water zone in Las Vegas
Valley, Nevada determined the sources and extent of ground-water contamina-
tion to develop management alternatives and minimize adverse effects. An
extensive, computerized data base utilizing water analyses, well logs, head
measurements, and surface flows was developed. Flow system analysis, gross
chemical data and tritium analyses were used in combination with trend
surface techniques to ascertain natural and contaminated ground-water quality
to depths of 0 to 50, 51 to 100, and 101 to 300 feet. At depths below 100
feetf the distribution of all constituents reflects natural controls.
Nitrat'e and chloride in the zone from 0 to 50 feet are closely related to
waste disposal activities, chief of which are industrial effluent, treated
sewage, and septic tanks. In addition, tritium is highly indicative of
return flows associated with distribution of Colorado River water in the
Valley- Localized contamination of shallow unconfined ground water and
rapid appearance of return flows is accentuated by pronounced vertical
hydraulic and stratigraphic boundary conditions present in the eastern and
western parts of the Valley. Nonparametric testing of extremely limited
historical water quality data to ascertain temporal changes, particularly
for the very shallow aquifers, yielded generally insignificant results.
This is believed due to the lack of data because changes are indicated by
gross chemical, tritium, and water budget data. Although the rudiments of
a monitoring program have been outlined, management objectives for shallow
ground water are undefined by responsible agencies, thus complicating the
reason(s) for monitoring and the level of effort required. Management of
shallow ground water bears on valley-wide and regional water management
objectives and will become increasingly important when nonpoint source
return flows double or triple to about 80,000 to 120,000 acre feet per year
in the next twenty to thirty years.
This report was submitted in fulfillment of Grant No. R800946 by
Desert Research Institute under the sponsorship of the U. S. Environmental
Protection Agency. This report covers the period November 1, 1969, to
January 31, 1974, and work was completed as of December 31, 1976.
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CONTENTS
Foreword iv
Abstract . . . . , v
Figures viii
Tables , xi
Metric-English Conversions • xii
Acknowledgement xiii
1. Summary of Conclusions 1
Research objectives 1
Aquifer framework and pattern of flow 1
Natural water quality 2
Effects of land and water use on shallow ground water . . 4
Data availability and analysis techniques 6
Shallow ground-water management implications 7
Problem areas of shallow ground-water management .... 8
Monitoring in relation to shallow ground-water
management 10
2. Recommendations 13
Ground-water monitoring 13
Water supply 14
Wastewater management 15
3. Introduction . 16
Research objectives 16
Method of study 17
4. Hydrogeologic Framework Affecting Return Flows 18
Introduction 18
Principal features of shallow ground-water occurrence
and use 20
Principal aquifer zones 24
Recharge and discharge relations 25
Hydrogeology of the near-surface zone 26
5. Ground-Water Quality 37
Introduction 37
Method of study 37
Deep ground-water quality (depth interval 101 to 300
feet) 41
Shallow ground-water quality (depth interval 0 to 50
feet) 48
Utility of the trend surface technique 71
Analysis of temporal changes in ground-water quality . . 74
VI1
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CONTENTS (continued)
Utility of the data storage and retrieval system .... 84
Return flows of industrial origin ........... 88
Tritium as an indicator of return flows ....... , 101
References ............................
Appendices ............................ 120
1. Characteristics of selected observation wells ...... . . 120
2. Location and description of water sampling stations ..... 138
3. Chemical analyses of Las Vegas Valley water samples from
February 1970 to April 1976 . . .............. 149
4. Chemical analyses used to determine historical changes
in ground-water quality .................. 196
5. Characteristics of wells used to determine historical
changes 'in ground-water quality .......... , . . . 205
6. Tritium sampling points and analytical results ....... 210
viii
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FIGURES
Number * Page
1 Location map showing Las Vegas Valley and the study area ... 19
2 Generalized east-west hydrogeologic cross section showing
ground-water occurrence and flow prior to extensive
development 20
3 Principal features of ground-water occurrence and develop-
ment 22
4 Photograph of Whitney Mesa as viewed looking northwest from
Las Vegas Wash 23
5 Photograph of caliche layers in the vicinity of Tropicana
and Polaris Avenues 23
6 Photograph of the upper Las Vegas Wash area showing a
principal fault scarp in the background and waterlogged
areas in the foreground 24
7 Close up view of the upper part of the fault scarp shown
in Figure 6 27
8 Photograph of an excavation for the Las Vegas Expressway
taken at Valley View Boulevard 28
9 Photograph showing cemented gravels in surficial alluvial fan
deposits in the vicinity of Charleston Boulevard and
Buffalo Drive 28
10 Photograph showing the degree of induration in cemented
gravel in the West Charleston Boulevard and Buffalo Drive
area 29
11 Closeup photograph of cemented gravel in the Charleston
Boulevard and Buffalo Drive area 29
12 Idealized geologic cross section A-A1 from the West
Charleston Boulevard area and Nellis Air Force Base .... 31
13 Idealized geologic cross section B-B' from the West
Charleston Boulevard area and downtown Las Vegas 32
14 Idealized geologic cross section C-C" from Las Vegas Boule-
vard South (the "Strip") and downtown Las Vegas 33
15 Water table map of the "near surface" zone, with an outline
of the ground-water flow model areas 34
16 Locations of surface water, spring, and seep sampling
stations 39
ix
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FIGURES (continued)
Number Page
17 Locations of sampling wells 40
18 Locations of domestic wells and selected test wells used
to characterize ground-water quality at depths of 101 to
300 feet in the period 1968-1972 42
19 First degree trend surfaces for total dissolved solids in
ground water at depths of 0 to 50, 51 to 100 and 101 to
300 feet deep 44
20 Distribution of total dissolved solids in ground water at
depths of 200 to 300 feet (manually contoured) 45
21 Sixth degree trend surface for total dissolved solids in
ground water at depths of 101 to 300 feet 46
22 Fourth degree trend surface for sulfate in ground water
at depths of 101 to 300 feet 47
23 First degree trend surface for chloride in ground water
at depths of 0 to 50, 51 to 100, and 101 to 300 feet ... 49
24 Locations of wells used to characterize ground-water
quality at depths of 51 to 100 feet 50
25 Map of the major soil associations in Las Vegas Valley ... 52
26 Photograph of an unimproved wash channel in the vicinity
of Harmon and Eastern Avenues 55
27 Photograph of an unimproved wash channel immediately west
of Eastern Avenue and south of Rochelle Avenue 55
28 Photograph of the dry wash in Figure 27 showing channel
encroachment as a result of fill operations in the
area east of Eastern Avenue and south of Rochelle
Avenue 56
29 Terminus of the wash shown in Figures 27 and 28 in a
proposed housing development 56
30 Photograph showing typical deep soil excavation and land
leveling in preparation for construction of a subdivi-
sion 57
31 Fifth degree trend surface for nitrate in ground water at
depths of 0 to 50 feet 60
32 Fourth degree trend surface for nitrate in ground water
at depths of 101 to 300 feet 61
33 Generalized map showing the sources and concentrations of
nitrate in ground water 63
34 Locations of wells and springs used to characterize
ground-water quality at depths of 0 to 50 feet 65
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FIGURES (continued)
Number Page
35 Fifth degree trend surface for total dissolved solids in
ground water at depths of 51 to 100 feet 68
36 Distribution of total dissolved solids in ground water at
depths of 0 to 50 feet (manually contoured) 69
37 Sixth degree trend surface for total dissolved solids in
ground water at depths of 0 to 50 feet 70
38 Fourth degree trend surface for chloride in ground water
at depths of 0 to 50 feet 72
39 Locations of wells sampled between 1915 and 1972 75
40 Locations of wells 101 to 300 feet deep with inferior
water quality 85
41 Hydrochemical facies in ground water at depths of 101 to
300 feet 87
42 Piper diagram showing variations in ground-water quality
along a selected flow path through Las Vegas Valley ... 89
43 Hydrograph showing Las Vegas Wash discharge in 1970 .... 90
44 Ground-water flow system cross section in the area between
the BMI tailings ponds and Las Vegas Wash 91
45 Distribution of total dissolved solids in shallow ground
water adjacent to the lower reach of Las Vegas Wash ... 93
46 Distribution of chloride in shallow ground water adjacent
to the lower reach of Las Vegas Wash 94
47 Distribution of nitrate in shallow ground water adjacent to
the lower reach of Las Vegas Wash 95
48 Locations of surface water and ground-water stations
sampled for tritium 103
49 Tritium concentrations versus water type 104
50 Approximate tritium rainout at Las Vegas for the period
1952-1971 106
51 Average annual tritium content of Colorado River water . . . 108
52 Map of the sanitation district service areas in Las Vegas
Valley 109
53 Approximate distribution of Colorado River water in Las
Vegas Valley Water District pressure zones from 1955-
1971 110
54 Colorado River water deliveries to Las Vegas Valley from
1955-1973 Ill
XI
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TABLES
Number
1 Comparison of Reported Water Levels in Wells of Different
Depths in the West Charleston Boulevard Area 35
2 Summary of the Characteristics of Major Soil Associations
in Las Vegas Valley 53
3 Areas Subject to Flooding in the City of Las Vegas 53
4 Peak Discharges Associated with Floods in Las Vegas Valley . 54
5 Nitrate Concentrations in Selected Ground-Water Samples
as Related to Nearby Land Use 66
6 Summary of Correlation Coefficients for the Trend Surfaces . 73
7 Number and Distribution of Chemical Analyses of Ground
Water for the Period 1912-1967 Inclusive 77
8 Year and Location of Chemical Analyses of Ground Water for
the Period 1912-1967 Inclusive 78
9 Methods Used to Determine Total Dissolved Solids in
Previous Studies . . 79
10 Summary of the Mann-Whitney Test Results to Evaluate
Historical Changes in Ground-Water Quality 82
11 Results of the Mann-Whitney Test to Determine Significant
Changes in Ground-Water Quality for the Periods 1912-
1945 and 1962-1972 83
12 Results of the Kruskall-Wallis Test to Determine Significant
Change in Ground-Water Quality for the Periods 1944-1972 . 84
13 Classification of Hydrochemical Facies 86
14 Ground-Water Quality in the Underflow of Las Vegas Wash ... 96
15 Las Vegas Wash Water Quality in the Vicinity of Henderson . . 97
16 Effects of Industrial Return Flows on Water Quality and
Chemical Mass in Las Vegas Wash 99
17 Percentage of Sodium, Chloride, Sulfate, and Total Dissolved
Solids Added to Las Vegas Wash by Ground-Water Return
Flows 100
18 Tritium Content of Shallow Ground-Water Recharged by Irriga-
tion Return Flows from Urban and Suburban Developments . . 113
xii
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METRIC-ENGLISH CONVERSION*
A. LENGTH:
Unit
millimeter
inch
toot
meter"11
kilometer
mile
Equivalent'"' <»
millimeter
1
25.40
304.8
1 000
1 000 000
1 609 000
inch
0.039 37
1
12
39.37
39370
63360
foot
0.003 281
0.083 3
1
3.281
3281
5280
meter"
0.001 000
0.025 40
0.304 8
1
1 000
1 609
kilometer
1 E-6
25.40 E-6
304.8 E-6
0.001
1
1.609
mile
0.621 4 E-6
15.78 E-6
189.4 E-6
621 .4 E-6
0.621 4
1
'Footnotes (or all parts of Table 5
(a) Equivalent values are shown to 4 significant figures.
(b) Multiply the numerical amount of the given unit by the equivalent value shown (per single amount of given
unit) to obtain the numerical amount of the equivalent unit (e.g.; 5 inches x 0.025 40 m/inch = 0.127 0 m).
(c) This is the SI expression, in base units or derived units, for the physical quantity.
B. AREA
Unit Equivalent1 •'""
sq. inch so., toot sq. meter"' acre hectare sq. kilometer sq. mile
sq. inch
sq. Foot
sq. meter"'
acre
hectare
sq. kilometer
1
144
1 550
6 273 000
15 500 000
1.550E+9
0.006 944
1
10.76
43560
107600
10 764 000
645.2 E-6
0.092 90
1
4047
10000
1 000 000
0.159 4 E-6 64.52 E-9
22.96 E-6
247.1 E-6
1
2.471
247.1
9.290
1 E-4
0.404
1
100
E-9
7
645,2 E-12
92.90 E-9
1 E-6
0.004 047
0.01
1
249.1
35.87
386.1
0.001
0.003
0.386
E-12
E-9
E-9
563
861
1
sq. mile 4.014 E+9 27 880 000 2 590 000 640
259
2.590
C. VOLUME:
Unit
Equivalent'"
CUDIC inch
liter
U.S. gallon
cubic foot
CUDIC yard
cuDic
meter"
acre-foot
second-
foot-day
cu. inch
1
61.02
231.0
1 728
46660
61 020
75.27 E+6
149.3 E+6
liter
0.016 39
1
3.785
28.32
764.6
1 000
1 233 000
2 447 000
u.s
gallon
0.004 329
0.264 2
1
7.481
202.0
264.2
325 900
646 400
cu. foot
578.7 E-6
0.035 31
0.1337
1
27
35.31
43560
86400
cu. yard
21 .43 E-6
0.001 308
0.004 951
0.037 04
1
1.308
1 613
3200
cu.
meter1"
16.39 E-6
0.001
0.003 785
0.028 32
0.7646
1
1 233
2447
acre-foot
13.29 E-9
810.6 E-9
3.068 E-6
22.96 E-6
619.8 E-6
810.6 E-6
1
1.983
sec-toot-
day
6.698 E-9
408.7 E-9
1.547 E-6
11. 57 E-6
312.5 E-6
408.7 E-6
0.5042
1
D. DISCHARGE (FLOW RATE, VOLUME/TIME):
Unit
Equivalent"' ""
gallon/min
gallon/minute 1
liter/second 15.85
acre-fooi/day 226.3
foot3/second 448.8
million gallons/day 694.4
meter3/second'cl 15 850
liter/sec acre-foot/day 1oot3/sec million gal/day meter'sec"-
0.063 09 0.004 419 0.002 228 0.001 440 63,09 E-6
1 0,07005 0.03531 0.02282 0.001
14.28 1 0.5042 0.3259 0.01428
28.32 1.983 1 0.646.3 0.02832
43.81 3.069 1.547 1 0.04381
1 000 70.04 35.31 22.82 1
E. VELOCITY:
Unit
loot/day
kilometer/hour
foot/second
mile/hour
meter/second'"
Equivalent"" "»
foot/day
1
78740
86400
126 700
283 500
kilometer/hour
12.70 E-6
1
1.097
1.609
3600
toot/sec
11. 57 E-6
0.911 3
1
1.467
3.281
mile/hour
7.891 E-6
0.621 4
0.681 8
1
2.237
meter/sec'01
3.528 E-6
0.277 8
0.304 8
0.447 0
1
* Taken from System International D1Unites, Metric Measurement in Water
Resources Engineering, prepared for the Universities Council on
Water Resources, June 1976,
Kill
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ACKNOWLEDGMENT
The author is most grateful for the assistance received from many
associates within Water Resources Center, Desert Research Institute.
Particular recognition is owed to Messrs. Nate Cooper, Herbert N. Friesen,
John Sanders, M. J. Miles, Robert J. McDonald, Ralph Patt and James Dinger
for their assistance in data collection and reduction. Critical advice and
manuscript review was generously provided by Drs. George B. Maxey, Gilbert
F. Cochran, Martin D. Mifflin, Mr. Dale Schulke, and Ms. Karyn Fallen.
Technical and clerical assistance was received from Judy Carpenter,
Margaret Herndon, Hazel Dewey, John Brekke, Carolyn McNeill, Kenneth Zellers,
and Lucy Dunaway Miller. Of the many student assistants, Peter Howells,
Fenton Kay, Guy Johnson, Bernard Serofman, Richard Leoni, and Walter Douthett,
deserve a special note of thanks.
Special recognition is given to Mr. Alan E. Peckham, the principal
investigator for the first two years of the project, for his efforts in
getting the study underway and in securing initial support within the Las
Vegas community and the U. S. Environmental Protection Agency. The assist-
ance of the first EPA project officer, Mr. Jim V. Rouse, is gratefully
recognized.
9
Many outside agencies and individuals provided financial and other
support, including the U. S. Bureau of Reclamation and the Nevada Division
of Colorado River Resources (formerly Colorado River Commission, CRC) .
Messrs. Arleigh West, former Regional Director for the Bureau and Donald Paff,
Administrator for the CRC, helped place the study in perspective relative
to the local and regional water quality management situation. The Bureau
and CRC provided financial and material support for establishing the water
quality laboratory and for an extensive water sampling effort on Lake Mead.
Mr. Carl Dewey, U. S. Bureau of Mines also helped in the establishment of
the laboratory. Financial support was obtained from the National Park
Service through Mr. Roger Allin, Superintendent of the Lake Mead Recreational
Area, and from the Fleischmann Foundation of Reno, Nevada. The ASK Con-
struction Company donated five ground-water monitoring wells in the Las Vegas
Wash area.
Several State, Regional, and County government officials deserve men-
tion. Among these are Drs. V. Ueckert and Otto Ravenholt of the District
Health Department, Mr. Charles Brechler of the Regional Streets and Highway
Commission, Mr. Francis Thorne of the State Engineer's Las Vegas Office,
and Messrs. Louis Anton and James Parrott of the City and County Sanitation
Districts, respectively.
The Las Vegas Valley Water District, under the direction of Mr. Thomas
Rice, provided financial support for modeling in the Las Vegas Wash portion
of the study. Staff members William Blackmer, Alan Bell, and Aldo Barozzi
were particularly responsive to our requests.
xiv
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Certain elements of private industry deserve specific credit. Basic
Management, Inc. (BMI), under the direction of Mr. Glen Taylor and various
companies in the Henderson industrial complex, provided access to private
property, financial support for stream gaging, and historical records. Mr.
James Zornes of Nevada Power Company furnished discharge and water quality
data concerning wastewater discharges. Several local consulting engineering
firms generously allowed the use of their borings logs to determine shallow
geologic and water table conditions. Mr. Oscar Scherer of Nevada Testing
Laboratories, Ltd., Mr. Robert Pride of Converse Davis and Associates, and
Mr. Aldon Strobeck of Strobeck and Associates, Inc. were particularly
helpful. The maintenance and engineering staffs of the Dunes, Stardust,
Sahara, and Desert Inn Hotels assisted us in locating on-site ground-water
drains as did officials of the Central Telephone Company, Montogomery Ward
and Company, and Sears, Roebuck and Company.
Final and lasting recognition is reserved for certain U. S. Environ-
mental Protection Agency personnel. Mr. Fredric Hoffman, the Project Officer,
provided unfailing support and critical review. The administrative support
of Dr. James P- Law, Jr. provided essential continuity in funding over a
four year period necessary to accomplish the goals.
xv
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SUMMARY OF CONCLUSIONS
RESEARCH OBJECTIVES
Intensive study of land and water use patterns and hydrogeologic condi-
tions in Las Vegas Valley focused on defining water quality conditions in
the shallow sediments to depths of 300 feet. Water quality in parts of the
near surface system, of aquifers and aquitards is greatly affected by urban
and industrial land and water use practices, cheif of which are liquid
waste disposal, overdraft of deeper aquifers, irrigation return flows, infil-
tration of overland flow, and disruption of natural soil conditions. The
study also sought to establish the relationship between such land and water
use patterns on basin wide water quality management, particularly the ground-
water aspects.
With the physical setting established in terms of natural conditions
and in relation to developmental patterns, the essentials of a water resources
systems response monitoring strategy were identified to assist in long-term
water quality management within the Valley and in relation to realities of
Las Vegas Wash and Lake Mead pollution problems. Hopefully the knowledge
gained will be a contribution having local importance. In a more general
sense, the objectives and study techniques have wider applicability and
relevance to the mandates for ground-water protection embodied in Public Law
93-523 (Safe Drinking Water Act).
AQUIFER FRAMEWORK AND PATTERN OF FLOW
Las Vegas Valley is an intermontane arid basin which contains a thick
sequence of alluvial sediments arranged vertically and laterally in a complex
system of aquifers and aquitards. The most permeable sediments are in the
northwestern and west-central parts of the Valley where the principal
volume of ground-water extraction has occurred to data, primarily from con-
fined aquifers at depths of 250 to 1,000 feet. Except in the west-central
area, these aquifers are overlain by extensive layers of poorly permeable
clay, silt, or caliche. Separating these productive zones from generally
less permeable sediments to the east is a series of faults and associated
scarps which impede eastward ground-water flow. The eastern part of the
Valley is characterized by primarily fine-grained sediments and a shallow
water table.
Immediately west of the main scarp in Las Vegas Valley, the near surface
zone consists of a thin layer of shallow alluvium underlain by extensive
caliche and other aquitard materials. The alluvium grades westward into fan
sediments and the zone is stratigraphically and hydraulically indistinguish-
able from the deeper aquifer. Northeast of the scarp there is no lithologic
basis for separation of a near surface zone. In the southeastern part of
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Las Vegas Valley, the near surface zone consists of saturated, unconsolidated
sands and gravels ranging in thickness from 20 to 100 feet. This area^is
underlain by an unknown thickness of poorly permeable fine-grained sediments,
probably belonging to the Muddy Creek Formation.
The near surface flow system is unconfined except possibly in a few very
localized areas. It is in hydraulic continuity with underlying saturated
sediments. Although perched water is locally present, it is not significant
in the context of water resources management in the Valley or relative to tne
present study. Previous to ground-water development which effectively began
in 1907 and constituted overdraft by the 1940's, recharge was principally
by upward movement from underlying aquifers. Because of pumping from deep
aquifers, the potential gradient in the near surface zone in the northwest
subarea has been reversed, causing shallow ground water to move downward
into underlying aquifers. In the southwest subarea, downward movement
occurs principally in the vicinity of heavy pumping while in other parts of
the subarea there is still upward movement into the near surface zone. In
the northeast subarea there is probably little downward movement of ground
water at depth. In lower Las Vegas Valley, ground water moves from the
near surface zone into underlying sediments on upper parts of the fan near
Henderson and the BMI industrial complex. In topographically lower parts
of this area there is upward movement with discharge to Las Vegas Wash and (or)
as evapotranspiration.
Under natural conditions, recharge to the valley fill was believed a
result of precipitation in the surrounding mountains, primarily those to the
west and north. Flow from the recharge areas via a deep aquifer system
involved an easterly or southeasterly path incorporating lateral and then
upward movement in the valley fill either as diffuse seepage or as localized
flow towards springs discharging in close proximity to fault planes. There
is some recent evidence that the recharge area may extend beyond the topographic
basin and involve the deep-seated limestone strata to a greater degree than
previously believed. Both the seepage and reinfiltration of the spring
discharges resulted in recharge of the near surface zone, discharge from
which was by evapotranspiration. There was no surface water flow of ground
water from the Valley and the principal discharge areas such as the
Meadows (Las Vegas) were well removed from the present locus of surface
discharge, Las Vegas Wash.
NATURAL WATER QUALITY
Ground-water quality in the deeper part (101 to 300 feet) of the shallow
zone largely reflects the combined influence of rock type, length of flow
path, and the effects of decreasing permeability and increased residence time
in an eastward direction along the flow path. Progressive increase in salt
content along the flow path in the deeper part of the shallow system (depths
of 101 to 300 feet) is a result of the aforementioned factors. These are
also influential at very shallow depths (0 to 50 feet), but the principal
influence on salt concentration is evapotranspiration.
Available chemical analyses of ground water for the period 1962 to 1968
for depth intervals 0 to 50, 51 to 100, and 101 to 300 feet were interpreted
using trend surfaces and a large data base, consisting of about 4,000 water
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analyses cross-referenced to over 6,300 wells. This base was developed from
existing records, and supplemented with additional analyses for gross chemis-
try and nutrients. Total dissolved soldis (TDS) in the depth interval from
101 to 300 feet increase in an eastward direction from 300 mg/£ on the
western and northwestern fringes of the suburban area to 3,000 mg/£ in the
vicinity of Las Vegas Wash. Variations in this interval are solely from
natural causes which include the basic flow system configuration, the geo-
logic matrix, and the position of the principal recharge and discharge areas
in the Valley. Whereas the distance from the recharge area in the Spring
Mountains to the 1,000 mg/£ TDS contour line is about 30 miles, dissolved
solids increase from 1,000 mg/£ to 3,000 mg/& in a distance of about four
miles in the area of concentrated ground-water discharge. Gypsiferous
sediments in the Paradise Valley area and adjacent to the Sunrise-Frenchman
Mountain complex account for the rapid increase in sulfate and calcium in
the southern and northeastern portions of the Valley. The effects of reduced
permeability and consumptive discharge in these areas are additive. The
trend surfaces for TDS at depths of 101 to 300 feet also infer that a pre-
viously undescribed and relatively undeveloped zone of good quality water
trends eastward across the northern portion of the study area. Additional
exploration will be necessary to substantiate this inference.
Nitrate1 (as NOa) and chloride concentrations at depths of 101 to 300
feet show little systematic variation. As a result of natural factors,
chloride gradually increases from 10 mg/& to 185 mg/£ near the area of
ground-water discharge. However, nitrate at this depth remains in loW con-
centration of about two to seven mg/5, throughout the area studied. Nitrate
concentrations exceeding ten mg/£ are locally present, indicating that in .
localized areas sewage effluent has contaminated aquifers deeper than 100 '
feet.
Soil conditions have an important bearing on shallow ground-water
agement. The soils data and the recent study by Cooley et al. (1973),
support the thesis that significant in-valley recharge by precipitatioft is
small and probably is on the order of several thousand acre feet or less
(Patt, 1977). In addition, the precipitated salts in surficial soils in
the central portion of the Valley are both allogenic and authigenic, the
latter originating as precipitation from ground water and/or former standing
water bodies. Return flow from irrigation water and liquid waste disposal
is likely to dissolve these constituents and increase the salinity of .shallow
grbund water. Also, the presence of essentially impermeable but discontin-
uous caliche and hard pan layers near the land surface limits the available
storage of return flows and diverts them laterally. Fine-grained soils pres-
ent on interfluvial surfaces in much of the urban and suburban portions of
the Valley are characterized by low infiltration rates and high salt content.
Minimal TDS concentrations occur in ground water associated with the
granular, less mineralized soils present on the medial and distal portions
of alluvial fans surrounding the urbanized areas and in the major drainage
courses such as Duck Creek and Las Vegas Wash. Maximum concentrations
occur in the central and southeastern areas underlain by finer-grained,
All nitrate data are expressed as nitrate
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mineralized soils, upward moving ground water, and evapotranspiration from
near surface ground water. The combined effect of these three factors plus
gradual enrichment along the flow path are evident from the steeper concen-
tration gradient in the area surrounding the lower reach of Las Vegas Wash.
Recharge by concentrated industrial wastes from the industrial complex in
Kendo-son also accounts for abnormally saline ground water in those portions
downgradient from the plant area and tailings ponds.
In general, ground water to depths of 50 feet is not potable because
of high salt content. Where primary or secondary treated sewage effluent
has been applied to the land surface, nitrate occasionally exceeds the
commonly accepted limit of 45 mgA (as NO3). Therefore, expanded use of
wastewater for irrigation should precede with caution because of the dele-
terious effects demonstrated with respect to very shallow ground water and
associated potential adverse effects on deeper aquifers. Use in areas with
lateral or upward flow gradients is favored because hydraulic drive to trans-
port contaminants to productive aquifers is absent. However, extensive
application of wastewater in certain areas is likely to result in water-
logging and (or) development of a base flow component in area drainage. Ex-
tensive reuse of sewage effluent in portions of the western and northern
sectors of the Valley is not recommended because deterioration of shallow, re-
latively high quality water could occur. Thick caliche layers and extensive
clay and silt sediments at shallow depths favor lateral migration and local
perching of return flows in much of the developed portions of the Valley.
Without deliberate management renovative effects of local soil columns will
decrease and noxious return flows may occur. In summary, additional hydrogeo-
logic and sanitary engineering studies will be necessary to select areas for
revise and to monitor the effects.
EFFECTS OF LAND AND WATER USE ON SHALLOW GROUND WATER
Although in-valley precipitation is not an appreciable source of re-
charge to shallow ground water, infiltration of various return flows into
the near surface aquifer as a result of water development has been going on
continuously ever since 1907 when the first artesian wells were developed.
Excess irrigation water infiltrated and many wells flowed freely until the
mid to late 1930's when the work of Livingston (1938) prompted the State
Engineer to require that abandoned wells be properly sealed and owners
limit the discharge to beneficial uses. The present study shows that return
flows from a variety of water and land use categories now amount to 46,000
acre feet per year (Patt, 1977).
Prior to extensive water use in the Valley, total ground-water outflow
via Las Vegas Wash was estimated at about 250 acre feet per year. As a
result of extensive industrial effluent disposal on the order of 11,000 to
17,000 acre feet per year from the early 1940's to date, ground-water dis-
charge to the Wash in 1972 was about 12,000 acre feet and contributed rough-
ly 60 to 70 percent of the measured salt flux leaving the Valley other than
in flood flows. In the urban and suburban areas, extensive mesquite groves,
stands of salt bush and tules have been removed and replaced with suburban
sprawl and the ubiquitous green lawn. Former discharge (by evapotranspira-
tion) of 25,000 acre feet per year has been replaced by ground-water recharge
of 46,000 acre feet per year. This recharge is believed to: 1) go
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into storage in the near surface aquifer, 2) move downward to recharge over-
drafted, formerly artesian aquifers, and 3) flow laterally toward Las Vegas
Wash.
Recharge to the near surface zone now is mainly a result of lawn, golf
course, and agricultural irrigation throughout the Valley and from sanitary
and industrial waste disposal practices adjacent to Las Vegas Wash. Of the
143,000 acre feet of water delivered in the Valley during 1973, about 46,000
acre feet or 32 percent were recharge to the near surface zone (Patt, 1977).
Of the total recharge in the Valley, about 27,000 acre feet were from irri-
gation and about 1,750 acre feet were from septic tanks. About 14,000 acre
feet of recharge occurred in the Las Vegas Wash area as a consequence of
municipal and industrial waste disposal and irrigation return flow.
Sewage effluents have freely infiltrated the near surface zone at *
numerous municipal and privately operated sewage treatment plants. In 1955
alone, 7,.000 acre feet of effluent infiltrated in the eastern part of the
Valley. Total recharge in the same year was 14,000 to 18,000 acre feet.
Irrigation of alfalfa with sewage from 1955 to 1969 caused water levels to
rise 14.6 feet or 1.04 feet per year. A severe waterlogging problem has
been recognized in a farm area of about 1,200 acres irrigated with sewage.
In 1973 there were over 5,000 irrigated acres in the Valley receiving 46,000
acre feet per year, only about 40 percent of which was consumptively used.
Available nitrate data clearly reflect the widespread addition of sani-
tary wastes from septic tank leachate and sewage effluent. In the south-
eastern part of the Valley, industrial wastes have caused extensive contami-
nation. Return flows from areas irrigated with sewage effluent or infiltration
of treated effluent from lagoons and outfall ditches have raised nitrate
concentrations in native ground water. Locally, concentrations exceed the
U. S. Public Health Service (1962) maximum recommended level to 45 mg/£ of
nitrate. There is a coincidence of above background concentrations of
nitrate in shallow ground water with known septic tank areas. The available
analyses, taken from throughout the developed portions of the Valley contain-
ing septic tanks, indicate increased nitrate both at the top of the zone of
saturation and within the shallow potable aquifers. Additional study is
necessary to determine whether nitrate is locally widespread in the shallow
aquifer or if it is appearing as leakage along well casings. The available
data base is inadequate in terms of lateral and vertical control. Nitrate
concentrations in very shallow ground water commonly exceed natural (back-
ground) values of 10 mg/£, and occasionally this occurs within a few years
after wastes are first introduced. For most of the Valley, concentrations
are less than 45 mg/£ but occasional peaks of 50 to 70 mg/& occur in some
wells and constitute a health hazard.
The widespread occurrence of increased concentrations of tritium in
shallow ground water is associated with known sources of recent recharge,
thus underscoring the marked hydrologic response to urbanization, and partic-
ularly irrigation and waste disposal practices. Septic tanks, irrigation
with sewage effluent, disposal of effluent by spreading on the land and
industrial waste disposal to unlined ponds are the most significant sources.
Contaminated return flows from the sources mentioned appear in ten years or
less and, in the case of most sources, are persistent for an even longer
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time period after disposal ceases. Tritium is particularly apparent in
shallow ground water in areas served by water derived wholly or in part from
the Colorado River. In these instances, the shallow aquifer an average of
49.4 tritium units (TU) compared to 20 TU in the western half of the Valley,
largely served by deep ground water containing 3 to 6 TU. Infiltration of
overland flow either from storm events or as tail water from lawn irrigation
in housing areas also contributes to chemical pollution and increased tritium
concentrations in shallow ground water. Ground-water return flow from the
BMJ complex, which uses only Colorado River water that has undergone little
dilution, contains 200 to 400 TU.
Five subareas of the Valley having similar hydrogeologic and water quali-
ty settings and patterns of water development were designated so the analyses
within each area could be statistically tested for temporal change in water
quality. With few exceptions, the testing procedures revealed no significant
change in ground-water quality regardless of the time periods or areas con-
sidered in the Valley. Significant change in TDS and chloride occurred in
the northwest part of the Valley where heavy pumping may have induced verti-
cal or lateral inflow of more saline shallow ground water. The data base
to assess temporal change is woefully inadequate, however.
DATA AVAILABILITY AND ANALYSIS TECHNIQUES
For three separate depth intervals or "slices", the use of trend surfaces
and their associated statistical measures proved very useful for evaluating
several hundred water analyses selected to depict the nature of lateral varia-
tions so as to clarify regional and local trends. By simplifying otherwise
complex patterns of ion distribution, variations attributable to natural and
man-related sources of water quality deterioration were identified. The
influences of natural and man-related sources of pollution are most evident
from the tritium, chloride and nitrate data and, to a lesser extent, from
variations in TDS. Tritium and nitrate, in particular, were useful indica-
tors of return flows associated with irrigation and effluent disposal.
Through 1967, only 412 analyses are available from wells ranging in depth
from 8 to 1,700 feet to document ground-water quality over an area of 150
square miles. Previous scientific studies account for 156 analyses with
the balance from the period 1964-1967 and, therefore, of limited historical
significance. Forty-four percent of the data are from wells of unspecified
depth, thereby reducing their scientific value. Only 2 percent of the
analyses are from the interval 0 to 100 feet. For areas in the eastern part
of the Valley where in places there is a rising water table from return flows,
there are essentially no analyses for the unconfined aquifer. Large areas
undergoing rapid suburban growth are essentially devoid of baseline water
quality data, hence future water quality changes associated with ongoing
development will be extremely difficult to assess.
An insufficient data base exists to define long-term trends in water
quality with respect to both the deep and the shallow aquifers. Neverthe-
less, vertical downward movement of poorer quality water into the deeper
aquifers on the western side of the Valley is indicated by static water level
measurements and hydrologic budget analysis (Harrill, 1976), lumped parameter
simulation modeling by Cochran and Wilson (1971), and the distributed digital
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simulation model of this study (Westphal, in prep.). The profusion of
agencies involved in water quality management might lead one to conclude the
historically weak effort in data collection is no longer a problem in Las
Vegas Valley- However, with the exception of efforts by the water utilities
with respect to municipal wells, ground-water quality data are not being
collected and plans to do so are not evident. Considering the type and
amount of data presently being collected, it is unlikely that a ground-water
specialist of the future will have any added advantage in terms of a data
base compared to that which now exists.
SHALLOW GROUND-WATER MANAGEMENT IMPLICATIONS
Management of water quality in a rapidly growing urbanized arid basin
involves surface water arid ground-water components. In the southwest there
commonly is overdraft of ground water and, subsequently, importation of
surfape water to meet increasing demands. Return flows associated with water
usage recharge shallow aquifers. Hydrologic effects are often pronounced
because natural hydraulic equilibrium is severly disrupted and a host of
water quality impacts are realized, some of which are adverse.
Results of the water budget phase of this study (Patt, 1977) indicate
tha£ recharge of the near surface aquifer from in-valley water use amounted
to about 38,500 acre feet in 1973. By comparison, the estimated total flux
of ground water under predevelopment conditions ranged from 21,000 to 35,000
acre feet per year. Water demands have steadily increased, particularly in
the last 30 years. Overdraft of the deeper, artesian aquifers probably began
in the 1940's when pumpage exceeded 40,000 acre feet per year. More recently,
pumpage approached 88,000 acre feet per year or roughly a 3 or 4:1 overdraft.
Increasing amounts of Lake Mead water, first used in the Henderson area in
the 1940's and in the eastern part of Las Vegas in the late 1950's, have re-
duced the use of ground water to about 73,000 acre feet per year in 1975.
Planned water use in the Valley for Lake Mead water will be as much as
350,000 acre feet per year. Aside from the fact that Lake Mead water has
about twice the TDS of ground water most widely usecj, there likely will be
pronounced changes in return flow quantity associated with a water budget
which is at least a ten-fold increase over predevelopment conditions. This
study has demonstrated that important hydraulic and water quality changes
have already occurred in the area of Las Vegas Wash.
Development of Las Vegas Valley has been and probably will continue to
be rapid. Principal long-term water planning efforts in the past have focus-
ed on provision of adequate water supplies, and to a considerably lesser
extent, on secondary treatment of sanitary wastes. Essentially no concern
or action has been shown with respect to nonpoint sources of return to the
shallow aquifers or to ground-water impacts on wastewater management and
vice versa. Despite the expenditure of several million dollars for water
quality management planning, recognition of the ground-water resource and its
active and passive roles in these planning objectives is not yet evident in
any comprehensive program.
Deep ground-water quality is related to overall water quality manage-
ment in several ways. It has long been known that the best quality water
already developed or potentially availabile in the Valley is from the deeper
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aquifers. Therefore, improved knowledge of this resource and the factors,
which may result in changes in quality, particularly adverse changes, are of
importance. Secondly, it is apparent that overdraft of ground water has
largely been a local phenomenon with the result that large areas of the
Valley have potable ground water that is largely underdeveloped. With in-
creasing distribution of Lake Mead water and a stated management objective
of annual ground-water pumpage reduced to 50,000 acre feet per year, the
trend toward underdevelopment is likely to continue and even increase. At
some future time, estimated to occur in the period 1990 to 2000, Las Vegas
Valley is expected to again face a potential water shortage. Beside impor-
tation of ground water from other valleys and in-valley water conservation
programs, moderate ground-water mining on a much more distributive basis
than at present is also an alternative to help meet future water demands and
to maximize the use of high quality ground water. Maintenance of this option
necessitates that preservation of existing high quality ground water be a
prime consideration in the adoption of a water quality management program in
the interim.
Documentation of ground-water quality conditions necessitates continued
collection of water samples from the principal production zones throughout
the Valley and from very shallow or near surface zones. Although the latter
are not presently considered a prime resource, their continued neglect may
render them a liability to other water quality management goals. The ground-
water monitoring network developed in the course of the study, in conjuction
with the data storage and retrieval system, has potential value for future
ground-water quality investigations. This network and data system is the
beginning of a program but should not be considered adequate on a valley-wide
basis or in terms of potential water management objectives. <
PROBLEM AREAS OF SHALLOW GROUND-WATER MANAGEMENT
Overland flow as sheet runoff plus flooding via diffuse systems of dry
wash channels removed much of the surficial accumulations of salt during
geologic time. With urbanization, drainage courses are improved, sheet flow
is reduced or eliminated and recharge from return flows constitutes the
net moisture flux through the soil profile. At present, salt removal is
restricted to the wash flood plains, which are being reduced through channel
improvement, and to selected areas where sheet flow is still possible; the
expected impact of these trends is increased ground-water, return flow and
decreasing water quality.
Use of wastewater in an arid zone urban environment characterized by
marked vertical boundary conditions and upward flow gradients results in the
widespread contamination of shallow aquifers and relatively rapid emergence
of return flows in surface water courses and as a contaminated veneer at
the water table. Past disposal of liquid wastes to urilined ponds near
Henderson has been unsuccessful for the most part. Although at least
230,000 acre feet of water have been disposed of to date, storage calculations
show retention of only 3 to 6 percent of the amount infiltrated which is
conservatively estimated at forty percent. Thus, true waste containment has
been minimal and, environmentally, the disposal scheme is a failure insofar
as wastes have migrated extensively into adjacent surface water and ground-
water resources over an area of about 16 square miles. In response to an
8
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EPA enforcement action, Stauffer Chemical Company and Montrose Chemical
Corporation of California (1972) estimated that the cost of recovery and im-
poundment of wastes in the subsurface as well as anticipated future waste
volumes would be $107,000,000. Noticeable reduction in flow volume and salt
flux is expected to take years, and several decades are necessary before
marked change in the total salt flux from ground water will occur after the
disposal practice is terminated. In retrospect and in looking toward the
future, such'massive waste disposal operations must be critically examined
relative to basin water quality management objectives and the spirit and
letter of the Safe Drinking Water Act as it relates to ground-water protec-
tion.
Recharge originating as industrial and sanitary wastes and nonpoint
sources of urban and agricultural return flows cannot migrate downward in
the discharge portion of a ground-water flow system? they are not safely con-
tained. Lateral migration is also necessarily short and the wastes typically
reappear in the natural discharge areas on the Valley floor. Effluent dis-
posal by surface spreading in the discharge portion of the flow system may
conflict with other land uses if wastes are transported to the land surface.
To minimize environmental impact, extensive liquid waste disposal in dis-
charge areas should occur in lined, impermeable basins where evaporation to
dryness occurs. Solid residues should then be safely landfilled or, possibly,
recycled'. Alternatively, recharge areas can be used to dispose of sanitary
wastes to allow dilution and other processes to reduce or eliminate waste
toxicity. Careful planning is essential to determine the extent and accepta-
bility of effects on other existing and future water uses if this alternative
is followed. Toxic wastes produced in the minerals processing industry are
not generally amenable to disposal in this manner and complete containment
becomes necessary.
Recharge to the shallow aquifer in the Valley proper has clearly
increased with time. Annual accretion in 1943 was 21,000 acre feet compared
to 26,650 acre feet in 1958, 27,600 acre feet in 1965, and 38,500 acre feet
in 1973. Recharge to the shallow system now exceeds the total water budget
for the Valley prior to settlement. Inefficient lawn watering accounts for
much of the recharge to the near surface zone. If present water and land
use patterns prevail, recharge associated with a future population of
750,000 may approach 75,000 acre feet per year, or roughly three times the
total water flux prior to development. More efficient irrigation could
reduce the present water demand by 15,000 acre feet per year and reduce
annual return flows by 11,000 acre feet.
Generally speaking, however, it is probable that important changes in
urban water use practices require institutional modifications and econom-
ic, incentives. A poll of valley residents by Reichert and Leland (1971)
indicated that price increases will probably result in reduced water usage,
particularly uses outside the dwelling. Fitzsimmons (1973) concluded that
tripling in water rates would be necessary to markedly reduce water demand.
With increased unit prices for potable water and wastewater treatment, per
capita water demand may decrease. However, total return flows can be expect-
ed to increase as a result of increased urbanization unless marked changes
in landscaping practices are instituted.
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MONITORING IN RELATION TO SHALLOW GROUND-WATER MANAGEMENT
This work clearly indicates the complexity of the shallow ground-water
system in terms of existing character, past and present impacts of water
development, urban land use, and various types of wastewater disposal and
return flow impacts. Understanding of the shallow ground-water zone, while
incomplete in some respects, is sufficiently detailed to allow qualitative
estimation of likely responses to changing water and land use practices in
the Valley. Although subtle and largely invisible, the present and potential
importance of shallow ground-water problems necessitates their consideration
in terms of hydraulic and water quality responses stemming from land and water
use or waste disposal in the Valley. Considering projected water supply
demands and expected uses (more than 350,000 acre feet per year, or pver twice
present water use) and the hydraulic and water quality responses documented
herein, there is every reason to believe that shallow ground water will
become increasingly relevant to basin wide water management.
If the foregoing is accepted, several options can be incorporated in
management policy for the shallow ground-water zone:
1. Controlled wastewater disposal (this has been the actual practice
in many parts of the Valley for industrial, municipal, and domestic
wastewaters).
2. Further development of municipal or domestic water supply (this too,
has been actual practice up to the present time in extensive areas
of the Valley).
3. Development of supplemental water for irrigation and industrial
purposes (where quality permits and economic development is
feasible).
4. Stabilize, reduce or elimate saline ground-water effluent to Laq
Vegas Wash.
The above options illustrate possible management directions, each of which
require monitoring programs and return flow management.
Unfortunately, it is unrealistic to specify a detailed shallow ground-
water monitoring program including such specifics as well location, design,
sampling intervals, etc., until basin wide water management policies are
clearly defined, and wastewater disposal practices qonsonant with the basin
wide water management policies are outlined. There is no general policy
direction which indicates the uses to be made of the shallow ground-water
system, and there is uncertainty with respect to development schemes for pro-
duction aquifers in some parts of the Valley. Also unclear is the policy
and management of return flow of water to the Colorado River in terms of
amounts and quality constraints. Despite the foregoing uncertainties, the
following known or extremely likely activities will affect shallow ground
water and, therefore, influence the context of any mon,itorining program:
1) continued in-valley use of potable water for lawn irrigation, limited
agriculture, evaporative cooling, etc., 2) sewage treatment and discharge in
the Las Vegas Wash area, 3) limited reuse of sewage for golf course
10
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irrigation, 4) overdraft of the deeper aquifers, 5) continuation of present
land and water use patterns (excepting large scale industrial waste disposal),
and 6) increasing use of Colorado River water.
In addition to the above, it is expected that shallow ground-water
resources will be intentionally and increasingly used for both waste disposal
and as a source of water supply for such nonpotable uses as cooling water or
irrigation. Use should fully reflect the nature of the local geologic
framework with respect to ground-water quality and availability and any
impacts on wastewater reuse.
An objective of this study has been development of a shallow ground-
water monitoring program to furnish data for assessing the hydrogeologic
effects of various water management plans developed for the Valley and
particularly as they bear on return flows to Las Vegas Wash and Lake Mead.
In part this has been achieved through definition of the principal problems
and demonstrating the objectives and methodology for data collection, as
well as data reduction techniques. The following items of consideration, in
terms of water quality and associated fluid potential data from sampling
points of known characteristics, are believed basic to a shallow ground-water
monitoring program in Las Vegas Valley:
1. The three-dimensional chemical state of the system should be
established through properly distributed water sampling points.
2. Individual sampling points should consist of fully cased and
properly sealed wells, some of which are piezometers and open to
a small or discrete portion of the system whereas others should
be high capacity wells open to relatively large production
intervals.
3. Wells should be sampled at set time periods and maximum effort
should be made to maintain sampling points.
4. Shallow ground-water return flows should be sampled by means of
natural springs/seeps and through interception of shallow zones
of high permeability (buried wash channels?).
5. Known areas of recharge from lawn watering, golf course irriga-
tion, and sewage/industrial waste disposal are particularly
significant sources of contamination and should be monitored.
6. Monitoring of shallow and underlying aquifers in areas of waste-
water reuse should precede, accompany and follow such reuse.
7. The monitoring programs of existing agencies should be carefully
reviewed to increase efficiency and information returns. It is
particularly important that information concerning well depths
and sampling depths be collected as part of ground-water sampling
programs.
8. The monitoring program should be amplified where and when needed
to answer specific questions alternative management proposals
raise with changing concepts and patterns of land and water use.
11
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All data should be reasonably representative of a common time frame. This
could be achieved by maintaining continuous water level records at a few
selected representative locations plus measurements collected throughout
the Valley and at least once during each period of maximum and minimum demand
each year. Methods of measurement should be accurate and datum elevations
should be surveyed, rather than estimated or assumed.
To obtain information about vertical hydraulic gradients, piezometer
nests should be installed and maintained at selected points throughout the
Valley. Obvious places are near pumping centers, in the vicinity of
selected housing developments, and near selected golf courses. Piezometers
should be installed so that distribution of hydraulic potentials in the
vertical section can be determined during construction.
At present, such fluid potential data are essentially nonexistent in
most of the Valley, and are key to relating water quality changes in under-
lying production aquifers to the shallow ground-water zone.
12
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RECOMMENDATIONS
GROUND-WATER MONITORING
Recommendation I
Formulation of monitoring objectives and implementation of a monitoring
program should directly stem from the broader objectives for management of
ground-water resources in the Valley. Because of the close relationships
between shallow ground water, land use, water use, and nonpoint return flows,
state and local agencies having authority and responsibility in these areas
should necessarily formulate these broad objectives. In addition, these
must be in consonance with regional water quality management goals established
by Federal authority; of particular importance is salinity control on the
Colorado River.
There is strong justification developed in this work for adopting a
monitoring program to provide useable data for evaluating the state of the
shallow ground-water system with respect to 1) water quality, 2) water table
(storage) fluctuations, 3) response in terms of surface discharge from the
Valley, and within the Valley, and 4) responses in terms of quality change
influenced by water transfer from shallow, low quality zones to deeper pro-
duction zones.
Recommendation II
Findings of the present study indicate the following considerations are
most relevant to formulation of management objectives for the shallow ground-
water resource in Las Vegas Valley:
1. Existing state of the system as documented by this study, and the
types and magnitudes of pollution and hydraulic impacts stemming
from activities in the Valley;
2. Wastewater disposal requirements of the future, and the mandate
of salinity control for the Colorado River Basin;
3. Continually increasing water supply demands, development, and
proportional generation of return flow wastewaters;
4. Development of an adequate data base for management schemes involv-
ing the shallow system (i.e., uses for water supply or waste
disposal);
5. The basic role the shallow ground-water zone takes in the genera-
tion of saline water return flow to Las Vegas Wash;
13
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6. The time lag response of this system to external stress (lead time
in planning for system responses is important); and
7. The great paucity of useable data to relate and predict probable
responses to external stress.
In summary, the policy and management approach must integrate both water
supply and wastewater disposal within the physical framework of the resource,
as outlined herein and in relation to the objectives and constraints posed
by Colorado River-Lake Mead salinity/eutrophication problems. The paucity of
information on temporal responses and associated rates of change suggest that,
at the very minimum, a valley-wide general monitoring program should be main-
tained that specifically address the shallow ground-water system as outlined
above.
Recommendation III
The ground-water sampling program of the District Health Department
should be continued and, if possible, repeated for areas identified in
this study as having high nitrate problems. Cross-referencing of water
analyses and drillers' logs, preferably using computerized storage and access,
is highly recommended.
The presence of nitrate in ground water at depths of 101 to 300 feet
may be related to improper well construction, particularly due to emplacement
of gravel packs and(or) perforated intervals open to shallow saturation
where nitrate concentrations reflect waste disposal practices.
Recommendation IV
Continued use of septic tanks and present or planned irrigation of green
areas with treated sewage effluent should be accompanied by local ground-water
monitoring programs to document changes in quality and storage. Use of
sewage effluent in areas with near surface caliche layers or in areas with
permeable gravels, both conditions commonly being present in the western part
of the developed area, are not recommended.
WATER SUPPLY
Recommendation I
Feasibility studies should be conducted to determine if the area of
relatively good quality ground water in the northeastern part of the Valley
can be more fully developed. Secondly, the cause(s) of nitrate contamination
in this area should be documented and corrective action taken.
Recommendation II
Throughout much of the Valley, investigations should be made to evaluate
the shallow ground-water zone in terms of potential water supply for such
purposes as irrigation or industrial supplies. Continually increasing water
demands and use, coupled with problems of rising water tables and increased
return flows of poor quality shallow ground water to Las Vegas Wash, indicate
14
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that one management alternative may involve concentrated development of this
potential supply for selected uses. Present knowledge of quality should be
supplemented by additional exploratory work, including test drilling, to
develop information on well design, spacing, water quality, and potential
yields.
WASTEWATER MANAGEMENT
Recommendation I
Economic and technical feasibility studies should be initiated to
evaluate locations, assimilative capacity, and long-term effectiveness of
salinity control through use of phreatophytes for consumptive use of saline
wastewater introduced to the shallow ground-water zone.
15
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INTRODUCTION
RESEARCH OBJECTIVES
Projections indicate Clark County population will double in about ten
years (Boyle-CHzM, 1969a). This growth is placing new demands on water
supplies to sustain present use patterns. The quality of these supplies,.
as well as the quality of the return flows to both Lake Mead and the ground-
water reservoir, need to be considered if comprehensive water quality manage-
ment is to accomplished.
The overall study was designed to quantitatively determine the effects
of past water use on ground-water occurrence and quality in Las Vegas Valley
and provide a basis for projecting both physical and hydrochemical changes
which are likely to result from increasing water utilization in the area. Of
particular importance was the development of an improved understanding of the
effects of water importation into a desert basin. The present report -focuses
on water quality aspects whereas reports by Patt (1977) and Westphal (1977)
address quantitative changes in the shallow zone water budget and digital
modeling thereof, respectively.
Water quality deterioration in Las Vegas Valley is attributable to
natural, hydrogeologic factors and to land and water use patterns. Impact
of these on basin wide water quality management is significant and will
require increased consideration in the future.
Some of the more important effects recognized or suspected to date
include:
1. An increase in TDS content of waters used in the area.
2. Increased return flows due to application of water to lawns,
recreational areas and commercial crops.
3. Leaching of soluble salts from the soil profile to shallow
ground water.
4. Alteration of ground-water potentials, thereby increasing dis-
charge into Las Vegas Wash and downward movement of shallow,
mineralized ground water into deeper aquifers heavily developed
for water supply purposes.
5. Industrial waste return flows are adversely affecting the water
quality in Las Vegas Wash.
16
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The water quality section of this research effort has the following
objectives:
1. Define the nature, extent, and cause of poor quality ground water
in the shallow parts of the Las Vegas Valley ground-water system.
2. Demonstrate the interface between land and water use patterns and
ground-water quality in relation to comprehensive basin wide water
quality management.
3. Develop a water resources system response monitoring program
designed to furnish appropriate hydraulic and chemical data to
assist in maintaining ground-water quality in Las Vegas Valley.
METHOD OF STUDY
Field-oriented hydrogeologic techniques and development of a data bank
from existing records encompassed the major thrust of the data collection
and interpretation effort. In addition, more than 2,300 water samples were
analyzed over a four year period for gross, trace, and nutrient constituents.
Efforts in the first two years focused on the foremost industrial and sanitary
sources in terms of effluent volume and quality and likely adverse impacts
on surface water and ground-water resources. The Basic Management Inc. (BMI)
industrial complex is adjacent to the Las Vegas Wash and wastes are primarily
from metal and mineral processing plants and chemical manufacturing. Other
major industrial effluent sources include cooling water from two power plants
and two gravel washing operations. Municipal wastes from four separate
sewage treatment plants also are tributary to the Wash.
Ground-water quality was determined by installation and sampling of
approximately 55 new wells for areas or depths where data were lacking and
by organizing analyses by the District Health Department. To obtain addi-
tional information such as static water levels and stratigraphic conditions,
analyses were cross-referenced to driller logs from more than 6,300 wells
in the Valley. This data bank of water analyses and well logs (not included
herein) is probably the most comprehensive data base available for strati-
graphic and hydrologic information concerning Las Vegas Valley. Tritium
data were developed and extensively utilized to identify return flows
resulting from urbanization and industrial water use.
To establish time-series data for ground-water quality, the sampling
program included reentry to wells sampled in the mid-1940's and mid-19601s.
If the original wells could not be located or had been destroyed, nearby
substitute wells with similar completion characteristics were selected.
The trend surface analytical technique, in conjunction with the data
bank, was implemented to reduce and portray extensive water quality and well
log data. Manual retrieval of analyses and logs and cross-referencing would
have been extremely inefficient considering the numbers available. Trend
surfaces have the attribute of portraying broad, overall trends rather than
detailed but complex variation of raw data. Statistics such as the correla-
tion coefficient relate how well the surface fits the raw data and therefore
provide a measure of how well the trends estimate spatial variability for the
system and parameter considered.
17
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HYDROGEOLOGIC FRAMEWORK AFFECTING RETURN FLOWS
INTRODUCTION
Las Vegas Valley is a major topographic depression covering 350 square
miles in southern Nevada. The area of study is shown in Figure 1. The
Valley trends northwest-southeast and is situated along the Las Vegas shear
zone characterized by intense structural deformation, primarily consisting of
right lateral movement (Longwell et al., 1965). Along this zone extensive
erosion of bedrock units created a basin at least 3,000 feet deep in the
central part of the Valley. Basin development by structural displacement
associated with normal faulting is also probable but evidence is scarce.
Faults downthrown to the east are present in the valley fill. Filling the
bedrock depression are thick deposits of sand, gravel, silt, and clay which
generally are coarsest toward the mountain fronts, becoming finer-grained
toward the lower portions of the Valley. These were deposited by ephemeral
streams originating in the highlands. Silt and clay deposits occupy the
central portion of the Valley.
Mapped surficial deposits (Price, 1966; Bingler and Luza, in
press; Dinger, in press) consist of alluvial sediments underlain by late
Pleistocene (Wisconsinan) pond/marsh deposits that lie on top of and are in-
ter fingered with Pleistocene fan and playa sediments. Maxey and Jameson
(1948) believed the foregoing were deposited in a large, ancestral valley
eroded into the Muddy Creek Formation which is largely composed of fine-
grained lake and alluvial sediments. The latter partly fills the large ero-
sional basin developed in the bedrock strata affected by the shear zone.
Sediments mapped as Muddy Creek,Formation (Longwell et al., 1965) are
exposed along the southern edge of Frenchman Mountain and the eastern edge
of Whitney Mesa. They are unconformably overlain by surficial sands and
gravels. The best exposure of the Muddy Creek sediment crops out in the
Whitney Mesa area and consists of a sequence of red to pink clays and silts
often more than twenty feet thick.
Extensive ground-water development is primarily from the Pleistocene
valley fill and possibly from coarse-grained facies of the Muddy Creek Forma-
tion which may be present in the western part of the Valley. At present,
essentially no use is made of ground water in the very shallow deposits and
associated caliche strata, or the underlying bedrock units, because of in-
adequate permeability, excessive depth to water, and/or poor water quality.
Extensive ground-water discharge as evapotranspiration and surface water
discharge occurs in the Las Vegas Valley Wash area which encompasses about
30 square miles and is located generally between East Las Vegas and Henderson
and between Las Vegas Wash and the BMI industrial complex.
18
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Figure 1. Location Map showing Las Vegas Valley and the study area.
-------
PRINCIPAL FEATURES OF SHALLOW GROUND-WATER OCCURRENCE AND USE
Disposition of aquifers in Las Vegas Valley is schematically shown in
Figure 2. In some parts of the Valley, the predevelopment pattern of upward
movement from the confined aquifers to the near surface zone has been modi-
fied in the last thirty years by heavy withdrawal of ground water from the
middle zone of aquifers. This zone occurs between depths of about 450 feet
and 750 feet (Maxey and Jameson, 1948). As a result, the piezometric head
in the confined aquifers has been greatly lowered. It was 60 feet above
land surface in parts of the Valley and it is now generally below the level
of- water in the near surface zone, which in the present study is defined as
the upper 300 feet of valley fill and, therefore, includes the near surface
and (part of) the shallow zones as defined by Maxey and Jameson (1948). Prior
to extensive ground-water development, the near surface zone was recharged
by upward movement from the underlying confined zones and by infiltration of
spring flows originating in the deeper aquifers (Maxey and Jameson, 1948).
Figure 2. Generalized east-west hydrogeologic cross-section
showing ground-water occurrence and flow prior to extensive
development (Malmberg, 1961, based on Maxey and Jameson, 1948).
A large marshy area known as "Las Vegas" was centered about Las Vegas
Creek forming an area of approximately eight square miles. A shallow water
table recharged by upward movement also was present in the Duck Creek drainage,
along the upper reaches of Las Vegas Wash and along the lower reaches of
Flamingo and Tropicana Washes. Other discharge areas were present in the
areas of Tule Springs and the Gilcrease Ranch, both in the extreme northwestern
20
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corner of the study area. In effect, discharge by evaporation and evaportrans-
piration equaled recharge by infiltration and upward movement and the near
surface zone was in equilibrium, with no surface flow leaving the Valley.
Beginning in the mid 1940's, this natural predevelopment condition underwent
rapid and dramatic change. Upward movement and spring discharge was greatly
reduced as a result of gradually increasing overdraft of the deeper (middle
zone as defined by Maxey and Jameson, 1948) aquifers, particularly those in
the western and northwestern portions of the suburban area. Whereas there
has been widespread reduction in artesian head, dewatering of shallow sedi-
ments has only occurred in a north-south trending belt on the western edge of
the developed area in the Valley. In the last 30 years, the near surface
zone as defined herein has been, for the most part, the locus of increased
recharge from surface sources and decreased discharge as a result of phreato-
phyte removal. Patt (1977) describes the changes in the near surface zone
water budget from 1943 to 1973.
Principal natural and cultural features bearing on the occurrence and
quality of shallow ground water in Las Vegas Valley are shown in Figure 3.
Fault scarps oriented generally north-south are geologically young but predate
man's presence in the Valley. Whitney Mesa and extensions of this lineament
to the north are perhaps the best surficial expressions of this faulting
(Figure 4). These delineate the transition from fine-grained sediments to
the east and coarser materials to the west. Lateral, eastward ground-water
movement is impeded by a decrease in transmissivity in the fault zone areas.
The largest springs in the Valley, most of which ceased to flow in the late
1940's and early 1950's, are generally located in close proximity to the
scarps. This is indicative of loss of transmissivity and conduit development
associated with the fault zones. Under natural conditions prior to heavy
pumping, these springs were characterized by very stable flow, water quality,
and temperature indicative of a deep-seated source. The springs are now
dry as a result of heavy pumping and reduced upward movement. Shallow ground
water on the order of 100 feet or less, commonly appears to accumulate in
the upthrown block and "weep" across an exposed scarp face. This is a mani-
festation of extremely low permeability of fine-grained surficial sediments
and pronounced boundary conditions exerted by near surface caliche layers,
common.in the western two-thirds of the Valley (Figure 5).
The areas of principal ground-water development and amount of production
for public water supply are shown in Figure 3. Principal public water supply,
developers include the Las Vegas Valley Water District, North Las Vegas, and '
Nellis Air Force Base. A second major user group, the resort industry, is
centered on the Las Vegas Strip and involves extensive development to support
lawn irrigation and other recreational uses.
As a result of return flows from nonpoint sources and from industrial
and sanitary waste discharges, an extensive high water table has developed
in the eastern part of the Valley particularly in the Las Vegas Wash area
(Figure 6). Because the prevailing ground-water flow direction is eastward
toward the lowest point in the Valley, saline, nutrient-laden ground water
surfacing along Las Vegas Wash constitutes a significant baseflow component
to surface flows and necessitates joint consideration of surface water and
ground-water factors in basin wide water quality management.
21
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M----IA-Location of geologic cross-section
^Xj-LosVegos Volley Water District-
West Charleston Well Field.
-Major irrigated land
'-Major areas of groundwater pump-
ing; number indicates withdrawal
in 100 acre feel for 1973.
-Major areas of phreatophytes.
-Direction of lateral ground-water
flow in the uncorifined aquifer
—Major escarpments
— Boundary of the area within Las
Vegas Valley where the water table
is less than 50 feet below land
surface
Figure 3. Principle features of ground-water occurrence and development.
22
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Las Vegas urban area
Whitney Mesa
Phreatophyte growth
due to waste discharge
Figure 4. Photograph of Whitney Mesa as viewed looking
northwest from Las Vegas Wash.
- *
Land surface
"li/
caliche layers
Figure 5. Photograph of caliche layers in the vicinity of
Tropicana and Polaris Avenues.
' :
-------
Fault scarp
Waterlogged areas
near Las Vegas Wash
Figure 6. Photograph of the upper Las Vegas Wash area
showing a principal fault scarp in the background and waterlogged areas.
PRINCIPAL AQUIFER ZONES
Four principal aquifers in Las Vegas Valley were identified by Maxey and
Jameson (1948). In the northwestern quarter of the Valley, they recognized
a near surface aquifer to depths of 200 feet. Below this, to depths of 450
feet, the shallow aquifer is present and consists of sand and gravel inter-
bedded with silt and clay. At the base of the shallow aquifer in parts of
the Valley they reported that a fairly persistent layer of blue clay overlies
the highly productive middle aquifer, the principal source of ground water
pumped in the Valley. A deep aquifer, recognized at depths below 700 feet
in the western half of the Valley, has only been developed in recent years.
Subsurface conditions vary laterally so the aforementioned aquifer relations
do not generally persist east of the principal scarp.
Because of decreasing quantities of sand and gravel from west to east,
aquifers in the eastern two-thirds of the Valley yield progressively less
water and wells rarely exceed a depth of 500 feet. There is a loss of pro-
ductivity accompanied with natural deterioration in quality toward the east
and southeast. As a result, considerably less ground-water development
occurs in these areas. Zones of highest transmissivity occur between depths
of 200 to 900 feet in the area between Charleston Boulevard and Tonopah
Highway and west of the East 1/2, Section 32, Township 20 South, Range 61 East
(20/61-32, E 1/2) . The principal pumping centers are shown in Figure 3. In
an area of one-half square mile, the main well field (Charleston well field)
of the Las Vegas Valley Water District produced approximately 60 percent of
all the ground water extracted in the Valley until 1973. Since the late
1960's, ground water production by the Las Vegas Valley Water District and
The location system used in this report is described in Appendix 3.
I
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the City of North Las Vegas has rapidly shifted to the north and west and has
featured deeper wells of higher yield.
Less transmissive tongues of cemented gravel separated by clay and silt
aquitards are present in the remainder of the urbanized area lying west of a
north-south line passing approximately through the southern reach of the Las
Vegas Strip. Relatively thin gravel lenses extend east of this line.
Throughtout the developed portion of the Valley, shallow aquifers in the
upper few hundred feet consist of sand and gravel lenses, or thin layers of
porous caliche conglomerate or caliche sandwiched between thick silt and clay
sediments. Highly permeable zones, probably representing former wash channels
extend generally east-west through finer-grained sediments and are most
common in township 21/61. Similar linear trending zones of high permeability
are likely in those portions of Paradise Valley located in the Duck Creek
subbasin.
In general, unconfined ground water is present at depths ranging from
less than 10 to more than 200 feet below the land surface in the urbanized
portion of the Valley. Where thick caliche units are present near the land
surface, near surface ground water can be locally confined under several feet
of head.
RECHARGE-DISCHARGE RELATIONS
Previous studies by Maxey and Jameson (1948) and Malmberg (1961) con-
cluded that recharge to the Las Vegas Valley ground-water basin is a result
of precipitation in surrounding mountainous catchment areas. Rainfall and
snowmelt in the Spring Mountains and, to a lesser extent in the Las Vegas
and Sheep ranges, probably infiltrate directly into the bedrock or flanking
alluvial, aprons. Minor recharge probably occurs in the McCullough Range and
possibly from the Frenchman-Sunrise Mountain block east of the Valley.
Studies by Winograd and Friedman (1972) and more recently by Winograd and
Thordarson (1975) indicate that the recharge area may extend beyond the topo-
graphic basin but to what extent in terms of area and volume of recharge is
unknown. Figure 3 illustrates the principal directions of lateral flow in
the near surface zone.
Estimates of recharge and discharge prepared by Maxey and Jameson (1948)
and Malmberg (1965) indicate ground-water flux of 21,000 to 35,000 acre feet
per year under natural conditions. With heavy overdraft of the artesian
aquifers beginning in the mid-1940's, followed by importation of water in the
1950's, the natural water balance has been severely disrupted in terms of
volume, distribution, and quality because discharge formerly equaled recharge
and no water (except flood flows) exited the Valley except flow from uncon-
trolled flowing wells in the 1920's and 1930's.
The principal sources of recharge to the near surface system include ir-
rigation return flows, septic tank and sewage treatment plant effluents,
industrial effluent ditches and disposal ponds, and upward flow from deeper,
artesian aquifers. Discharge from the system occurs as direct evaporation,
evapotranspiration from phreatophytes, and discharge to surface water
courses. Ground-water discharge causing surface flow is significant only in
the Las Vegas Wash area. In the remainder of the Valley recharge to the near
25
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surface system results in positive change in storage, downward movement to the
deeper, heavily pumped aquifers, and development of small springs and, seeps.
Under natural, predevelopment conditions, the only ground-water outflow
from the Valley was Las Vegas Wash underflow which is estimated at about
250 acre feet per year or less. At present an additional 12,300 acre feet
per year of underflow surfaces in the lower reaches of Las Vqgas Wash (Kauf-
mann, 1971; Westphal and Nork, 1972). In the developed portions of the
Valley, major springs and artesian wells have ceased to flow as a result of
heavy pumping. Extensive mesquite groves and stands of saltbush, that formerly
discharged 25,000 acre feet per year have been removed and replaced with
suburban sprawl and extensive lawns. Exclusive of Henderson and the BMI
effluents, recharge to the shallow aquifer in 1973 amounted to 38,500 acre
feet per year (Patt, 1977) and represented water which was 1) going into
storage, 2) leaking downward to recharge the deeper aquifers, or 3) flowing
laterally toward Las Vegas Wash.
HYDROGEOLOGY OF THE NEAR SURFACE ZONE
The near surface zone as used herein is defined as that portion of the
total ground-water system occurring within 300 feet of land surface. It,
therefore, includes the near surface zone and part of the shallow zone as
defined by Maxey and Jameson (1948). Initial attempts to more rigidly
characterize shallow ground water in terms of boundary conditions, permeabi-
lity distribution, or water quality revealed a high degree of natural vari-
ability and a lack of precise data. Therefore, a "slice" approach was used,,
analogous to that of Domenico et al. (1964).
Based on their observations in the period from 1940 to 1956, Maxey and
Jameson (1948) and Malmberg (1965) described the near surface zone as follows:
1. Depths to water range from a few feet to a few tens of feet below
land surface.
2. Recharge is by upward movement from underlying aquifers and by
downward percolation of surface water.
3. Natural discharge is solely from evapotranspiration.
4. Transmissivities are low and the amount of water moving laterally
through the sediments is small.
In the present study several thousand well logs and soils/engineering
reports were examined for lithologic and water level data to determine 1) if
there is a geologic basis for differentiating between the near surface and
deeper flow systems and 2) the areal extent of the near surface system.
Except in a few cases where well locations were verified in the field, water
level elevations and elevations of lithologic horizons were obtained through
use of lh minute or 15 minute topographic maps in conjunction w4.th reported.
well locations. As expected, drillers' descriptions of lithology were ex-
tremely variable with respect to units encountered in, a given area.
26
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A network of northward trending, roughly parallel fault scarps occupy
the central portion of the Valley (see Figure 3) and affect ground-water move-
ment. The most prominent scarp extends northwest from 22/62-4 in the vicinity
of Whitney Mesa to downtown Las Vegas th n north through North Las Vegas
and the Craig Country Club (20/61-3). Lower Las Vegas Valley is considered
to be the area east of Whitney Mesa and southeast of the Las Veaas Wastewater
Treatment Plant. East Las Vegas, Pittman, and Henderson are the principal
communities in lower Las Vegas Valley.
The near surface zone consists primarily of clay and silt with inter-
stratified deposits of sand, gravel, and caliche. Near the main north-south
scarp, fine-grained Muddy Creek or Pleistocene sediments are widespread,
particularly east of the scarp. Figure 7 shows the fine-grained sediments
comprising the scarp in the vicinity of Cashman Field in North Las Vegas.
Ground water flowing across the scarp face exists the excavation indicated
by the arrow. The horizontal line indicates the approximate upper boundary
of saturation. Farther west in the vicinity of Valley View Drive and the
Las Vegas Expressway, areally extensive and highly indurated caliche is at
the surface or near surface. As shown in Figure 8, the fine-grained sediments
between caliche layers are saturated and require emplacement of under-drains
to allow construction in this area. Subsurface conditions are nearly identi-
cal in the vicinity of Decatur Boulevard approximately three-quarters of a
mile west.
Silt, clay soils
Figure 7. Closeup view of the upper part of the fault scarp shown
in Figure 6. Photograph taken approximately one-quarter mile
south of Cashman Field in the vicinity of 9th Street and Harris Avenue.
In the vicinity of the recently constructed West Charleston reservoir
near Buffalo Drive, there is a thick section of unsaturated, moderately well
cemented sands and gravels (Figure 9). The caliche is sufficiently indurated
that fracturing occurs across rather than around the larger clasts (Figure 10)
27
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Water table Friction piles
Land surface
". •
<:^-
Figure 8. Photograph of an excavation for the Las Vegas Expressway
taken at Valley View Boulevard.
Figure 9. Photograph showing cemented gravels in surficial
alluvial fan deposits in the vicinity of Charleston Boulevard and Buffalo Drive,
-------
Nevertheless, close-up views reveal the rounded particles and give some indi-
cation of high residual porosity and permeability, despite cementation (Figure
11). Significant amounts of aquitard materials in upper zones are absent from
driller reports for the areas west of Jones Boulevard. Displacement appears
to decrease with each minor scarp west of the main north-south scarp. Sub-
surface data from water well logs show an east to west facies change from
fine-grained sediments to coarser materials characteristic of alluvial fans.
Land surface
10 feet
Figure 10. Photograph showing the degree of induration in
the West Charleston Boulevard and Buffalo Drive area.
Note the occurrence of fracturing across clasts.
Figure 11. Closeup photograph of cemented gravel in the
Charleston Boulevard and Buffalo Drive area (note dime for scale)
-------
To clarify understanding of the facies changes generally described above,
east-west stratigraphic cross-sections (Figure 12, 13, 14) were prepared from
logs of wells and soil borings. Although the cross-sections portray the
general changes in sediment type and distribution, there is insufficient litho-
logic description in the available logs to describe separate aquifer zones
in detail. Attempts to use Markovian analysis of vertical variability as an
estimate of lateral variability were also unproductive.
It is apparent from the cross-sections that the upper 300 feet of sedi-
ments in the western part of the Valley contain considerably more coarse-
grained sediments in the form of sand, gravel, cemented gravel and caliche
conglomerate. The thin but impermeable and extensive caliche units and inter-
bedded silt and clay layers create marked permeability boundary conditions.
In the eastern part of the Valley, transmissivity decreases due to the
dominance of caliche, silt, and clay. Although only one or two fault planes
are shown in the cross-sections, other faults with small throws are believed
present, particularly west of the scarp shown.
In addition to stratigraphic or lithologic definition of the near surface
zone, water level information was also utilized. Figure 15 depicts the
hydraulic potentials in the near surface zone between 1970 and 1973. In the
western part of the Valley water level data were obtained from soil boring
records and driller reports for wells completed in the near surface zone.
The exception was in the general area west of Jones Boulevard where the
bottom of the near surface zone can not be distinguished. In that area, water
levels in wells 300 feet deep or less were used. Because it was not possible
to define the near surface zone in the northeast part of the Valley on the
basis of lithologic data, a well depth criterion of 300 feet or less was also
used.
Water level data were examined to determine the influence of geologic
materials on hydraulic potentials in the near surface zone in an eight square
mile area centered on Charleston Boulevard west of Rancho Road. The area
was selected for study because of its proximity to the Las Vegas Valley Water
District's Charleston well field (20/61-32), the known presence of extensive
layers of caliche, and availability of well data. To minimize the effect of
temporal variation in driller reported water levels, wells were divided into
groups according to date drilled. Water level comparisons are shown in
Table 1.
It is evident that heads were above the bottom of the near surface zone
where it was distinguishable as such. This was true even in the vicinity of
the well field where potentials in the deep artesian aquifer were 160 feet
below land surface. The 1971 and 1972 data indicated a gradient reversal,
i.e. downward, probably as a result of pumping from the middle and deep
aquifers. The downward gradient provides opportunity for the migration of
water from the near surface aquitard into underlying middle zone aquifers.
Furthermore, the head data in Table 1 suggest this condition has existed since
the mid-1950's. Thus, downward transfer of poor quality water may be occur-
ring in this part of the Valley.
From the efforts to stratigraphically and hydraulically define the near
surface zone and from careful review of previous studies, the Valley was
30
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SEE FIGURE 3 FOR LOCATION
Figure 12. Idealized geologic cross section A-A1 from the West
Charleston Boulevard area and Nellis Air Force Base.
-------
8
WEST
w
to
SEE FIGURE 3 FOR LOCATION
Figure 13. Idealized geologic cross section B-B! from the West
Charleston Boulevard area and downtown Las Vegas.
-------
c
WfST
CO
u>
SEE FIGURE 3 FOR LOCATION
Figure 14. Idealized geologic cross section C-C1 from Las Vegas Boule-
vard South (the "Strip") and downtown Las Vegas.
-------
>o«TB«jTi— NORTHWEST
•—'MODELING AREA
-LINE OF EQUAL
WATER LEVEL
ELEVATION IN FEET
ABOVE MSL DATUM
Figure 15. Water table map of the "near surface" zone, with an outline
of the ground-water flow model areas.
34
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TABLE 1. COMPARISON OF REPORTED WATER LEVELS IN WELLS OF DIFFERENT
DEPTHS IN THE WEST CHARLESTON BOULEVARD AREA
T/R
20/61
20/60
21/60
21/60
21/61
20/61
20/60
21/60
21/60
21/60
Location
Sec
32
36
36
01
01
02
04
33
36
36
01
12
11
Quarter
231
422
321
443
444
443
41
432
444
33
434
31
34
42
42
41
41
42
42
41
42
33
22
22
22
23
23
22
22
222
323
233
334
244
342
124
232
434
123
Year
Drilled
1951
1951
1952
1955
1955
1955
1959
1960
1960
1959
1960
1961
1960
1959
1962
1954
1955
1955
1954
1955
1955
1953
1957
1955
1955
1954
1954
1955
1955
1971-
1972
"
»
,.
"
"
.,
"
"
"
Well
Depth (feet)
70
140
160
150
160
206
81
225
250
200
250
252
300
300
300
110
150
162
no
175
220
230
246
240
243
260
265
270
300
50
170
395
149
830
170
154
320
273
700±
Water level
elevation*
2100
2075
2100
2156
2160
2165
2150
2149
2135
2213
2130
2135
2130
2125
2120
2180
2157
2170
2160
2162
2150
2186
2135
2190
2190
2165
2165
2140
2155
2057
2038
2007
2151
2002
2132
2129
2031
2044
2028
Comments
Very shallow wells
indicating water
table position only
No boundary indi-
cated. Wells
located between
Decatur Blvd . and
Wilshire street
No boundary
indicated.
Boundary estimated
to be between 200
to 252 feet below
surface
Boundary estimated
to be 230 to 246
feet below surface
Boundary estimated
to be 243 to 265
feet below surface
Boundary between
shallow and deeper
aquifers indicated
Boundary between
near surface and
shallow aquifers
indicated
Boundary between
shallow and near
surface aquifers
indicated
No boundary appar-
ent from water
levels. Located
between Jones Blvd.
and med line of
21/61-11
Final static water level reported by driller at time of well completion. Static
Tevel in feet above mean sea level.
35
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divided into four separate areas, each of which have broadly similar hydraulic
and geologic conditions (see Figure 15). The lower reach of Las Vegas Wash
and environs constituted one such area whereas the remainder were in the
urbanized portion of the Valley-
36
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GROUND-WATER QUALITY
INTRODUCTION
Previous documentation of ground-water quality in Las Vegas Valley, re-
gardless of depth, is notoriously deficient. The resource, in terms of quali-
ty, has largely either been taken for granted or ignored. In-valley effluent
disposal practices are cases in point. Very limited discussions of water quality
are presented in Mendenhall (1909), Carpenter (1915), Hardman and Miller
(1934), Maxey and Jameson (1948), and Malmberg (1965). An unpublished water
quality map produced by Domenico and Maxey (1964) depicted zones or regions
of TDS as indicated by specific conductance. The water sampling program of
the District Health Department resulted in several thousand water analyses
for the period 1968 to present but there was no previous attempt to reduce
and interpret the data. The Las Vegas Valley Water District and the City of
North Las Vegas have additionally monitored their wells in the western part
of the Valley; however, few data prior to 1969 are available. The present
study, then, represents the first attempt at description of ground-water
quality in Las Vegas Valley. A subsequent effort by Dinger (in preparation)
relates shallow ground-water quality to geologic conditions.
Changes in ground-water quality with time in Las Vegas Valley might be
expected for a number of reasons, some of which are:
1. Extensive overdraft of deeper artesian aquifers resulting in down-
ward leakage of poorer quality water from overlying aquitards and
induced lateral inflow of poorer quality water in the central
portion of the basin.
2. Terrestrial disposal of sanitary and industrial wastes.
3. Septic tank waste disposal systems.
4. Importation of increasing amounts of more saline Lake Mead water
and subsequent distribution within the Valley.
5. Irrigation of lawns, golf courses, parks, and commercial crops
with potable and wastewater, resulting in leaching of highly
alkaline soils and salt concentration due to consumptive use.
6'. Discharge from evaporative coolers.
METHOD OF STUDY
For the urban and suburban areas of the Valley, ground-water quality
variations through space and time were analyzed using trend surfaces and
37
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nonparametric statistical tests., respectively. With background or ambient
conditions established, attention was then directed to specific land and water
use practices instrumental in affecting ground-water quality. In this regard,
tritium and nitrate data were used to document return flows associated with
urbanization and industrialization. Three chemical data bases were utilized:
1) historical analyses from 1909-1964 (supplemental by resampling of the same
wells or substitutes, where possible), 2) chemical data on file at the
District Health Department and representative of valley-wide sampling of
domestic and municipal wells from 1968-1972, and 3) approximately 2,000 water
analyses of shallow ground water, effluents and potable water sampled as part
of the study in the period 1970-1973.
Extensive water sampling, flow measurements, and installation of 36 new
wells in the first year of the study resulted in the generation of an essen-
tially new data base for the lower reaches of Las Vegas Wash and adjacent
areas in Henderson, Whitney, Pittman, and East Las Vegas. In the remainder
of the Valley, principal reliance was placed on available water analyses and
well records, supplemented with a limited number of shallow wells and water
analyses therefrom. Well characteristics are stated in Appendices 1 and 5.
Surface and ground-water samples from stations located throughout the
Valley as shown Figures 16 and 17 and described in Appendix 2, were collected
from February 1970 through September 1973 to characterize quality with respect
to gross chemistry, trace elements, nutrients, and tritium. This effort
focused on sampling areas and depths not included in the District Health
Department sampling program and(or) to supply new data for locations previous-
ly sampled by earlier researchers. In this way temporal comparisons could be
made. With respect to the Las Vegas Wash area, samples for gross chemical
analysis were predominantly collected on a monthly basis for ground-water
and surface water points. For all samples except those collected for tritium
analysis, the following determinations were made: pH (laboratory), specific
cpnductance (field and laboratory), temperature, bicarbonate, carbonate,
chloride, sulfate, phosphate, fluoride, nitrate, ammonia, and four principal
cations. Analytical results for water samples collected in the course of
the study are shown in Appendices 3 and 6. With the exception of the section
describing historical changes in water quality, the interpretations herein
are based on samples collected from February 1970 through September 1973.
Subsequent data shown in Appendix 3 are for information only.
Spatial variations in ground-water quality, particularly for depths
below 50 feet, were determined largely from District Health Department data.
Analyses from January 1, 1968 through 1972 were selected for depth intervals
0 to 50 feet, 51 to 100 feet, and 101 to 300 feet providing the anion:cation
ratio was in the range 0.9 to 1.1. From card decks of acceptable analyses
plots of sampling point locations were prepared to determine density of data
points in the study area for the three depth intervals selected. In areas
of high density, analyses for depth intervals 51 to 100 feet and 101 to 300
feet were averaged to one value per quarter section to avoid undue weighting
of the polynomial equations describing the trend surfaces. For these same
depth intervals, data decks containing only actual, versus averaged, data
were prepared to plot the locations where various water quality parameters
exceeded a threshold value, usually the U. S. Public Health Service (1962)
standard for drinking water.
38
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-Sompling point location;
includes surface flows, springs,
seepages, underdrams^etc.^
Defined in Appendix 2 as "|_W''
Figure 16. Locations of surface water, spring, and seep sampling stations.
39
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Sampling paint location
consists of a well
in Appendix 2 as
Figure 17. Locations of sampling wells.
40
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The data base was also used to produce hydrochemical fades maps for the
depth interval from 101 to 300 feet. The plotting routine was used in combi-
nation with a program which categorized each water analysis into 1 of 16
facies or classes of water quality resulting from different sediment composi-
tion and source areas, variations in residence time within the flow system,
and effects of ion exchange with fine-grained sediments. Domains of dominant
classes or facies were mapped to show trends throughout the area where data
were available.
The data decks were also used to generate trend surfaces depicting the
trend for various water quality parameters. Data availability varied with the
depth interval considered. In the case of the depth interval from 0 to 50
feet, only TDS, chloride, and nitrate were considered as the water was clear-
ly not potable and these parameters were considered most indicative of return
flows from developed and agricultural areas. In addition to the trend
surfaces for each parameter, CALCOMP plots of actual values by location were
made to enable a visual scan of the raw data and selection of the contour
interval and reference contour for the trend.
The trend surface technique involves fitting polynomial surfaces to map
data by means of a general linear model incorporating a least-squares fit
of a planar or curvilinear surface to the observed data. More complex sur-
faces involved higher order polynomials and more terms in the equation
collectively relating each datum (Z) to its location (X, Y) in the area of
consideration. In theory, there is no upper limit to the exponents but the
most useful trends seldom exceed, the fifth or sixth degree. The coefficient
of correlation statistic expresses the variation accounted for, which typically
is in the range of 60 to 90 percent and progressively greater for the higher
order polynomials.
In the past, trend surface analysis has primarily been applied to strati-
graphic, structural and sedimentation problems involving such topics as analy-
sis of lithofacies variations, source areas for heavy mineral assemblages, and
evaluation of economic deposits of oil, gas, and ore. Davis et al. (1969)
applied trend surface analysis to a problem involving ground-water use,
replenishment and aquifer characteristics in Indiana. A bibliography of the
applications is found in Krumbein and Greybill (1965) and in Lustig (1969).
For the present study, trend surfaces were relied upon to portray chemical
quality of ground water for several reasons. From a research standpoint,
the method had not been adequately tested and applied to ground-water quality
problems. Another consideration was the need to reduce and generalize a
great mass of chemical data, some of which were of questionable veracity.
Retrieval of raw data for manual plotting and contouring would have been ex-
tremely time consuming and inefficient. Finally, broad overall trends are
analytically more useful in describing variations in Las Vegas Valley.
DEEP GROUND-WATER QUALITY (depth interval 101 to 300 feet)
Figure 18 shows the location of water analyses taken to describe changes
in the depth interval from 101 to 300 feet. Fewer analyses available in
approximately the central portion of the study area reflect gradual destruc-
tion of wells in the older urban developments which are now relying on muni-
cipal water systems. Light density in the north-central portion is largely a
result of nondevelopment.
41
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BOUNDARY OF AREA STUDIED
• WELL LOCATION
Figure 18. Locations of domestic wells arid selected test wells used
to characterize ground-water quality at depths of 101 to
300 feet in the period 1968-1972.
42
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First order or regional trends in TDS for the three depth intervals con-
sidered are shown in Figure 19. At depths of 101 to 300 feet, the progres-
sive increase in mineralization of ground water along the valley-wide flow
path is primarily a function of natural hydrogeologic controls. This is
shown in more detail in Figures 20 and 21, which are hand-contoured and sixth
degree trends of TDS at depths of 200 to 300 feet and 101 to 300 feet, re-
spectively. Although both maps generally agree, the hand-contoured version is
less useful in depicting broad, valley-wide conditions, despite the fact that
data are averaged to one value per section. The sixth order trend (Figure
21) reveals minimum concentrations of approximately 300 mg/£ in the north-
western sector along the principal ground-water flow path into the Valley.
From this point flow is eastward across the northern half of 20/61, and
southeastward toward Las Vegas Wash. Mineralized ground water present along
the west central and southern portions of the study area reflects the presence
of soluble, gypsiferous - Mesozoic sediments in the recharge areas and contig-
uous alluvial fans in the southern portion of the Spring Mountains. Other
factors contributing to the mineral content of ground water in this part of
the Valley include longer time in the flow system, less annual recharge
o water flux, and decreased permeability associated with finer-grained shale
and siltstone bedrock and resulting detritus. In contrast, the central and
northern portions of the Spring Mountains are composed primarily of Paleozoic
carbonate strata with high secondary permeability, essentially no evaporites,
and greater annual recharge due to higher average elevation. As a result,
ground water is of higher quality.
In general, the pattern for TDS for the zone from 101 to 300 feet is
one of progressive increase along the flow path. This is an expected and
normal pattern because the dominant sink is the lowland area centered on Las
Vegas Wash, the point toward which all ground water flows. The mineral con-
tent of deep ground water in the southeasterly portion of 21/62 increases
from 1,000 to 3,000 mg/& in a distance of about four miles. Comparing this
with the change in the distance from the prime recharge area in the Spring
Mountains to the 1,000 mg/£ contour line, (roughly 30 miles), gives an indi-
cation of the role played by the composition and permeability of fine-grained
valley-fill.
The east-west trending zone of relatively good quality water extending
across the northern portion of the study area to the central portion^ of 20/62,
and then southward toward Boulder Highway is indicative of favorable condi-
tions for ground-water development. These might include rather permeable
' sediments and/or significant ground-water inflow.
Warm ground water below depths of several hundred feet in the southern
and southeastern portions of the study area also contributes to the dissolved
solids in the shallow aquifers. Warm ground water and a mineral spa are pre-
sent in 22/62-21. Water from an artesian well (LG002) 1,000 feet deep in
section 4 of the same township varied from 22.2 to 33.5°C and contained be-
tween 3,127 and 4,660 mg/£ TDS when sampled in 1970. Other wells 300 feet
deep or greater, with water containing in excess of 2,000 mg/£ TDS, are
reported in 22/62, by Domenico and Maxey (1964) and Hardman and Miller (1934).
Sulfate concentrations in ground water at depths of 101 to 300 feet are
shown in Figure 22 which is similar in pattern to the TDS plot discussed
43
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/ r—7-
0 to 50feet depth; contour interval
JOOOmg/i
••—51 to 100feel depth; contour Interval
500mg/l
— 101 to 300 feet depth; contour interval
2no rna/1.
Figure 19. First degree trend surfaces for total dissolved solids in ground
water at depths of 0 to 50, 51 to 100 and 101 to 300 feet deep.
44
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Contour Interval 400mg/l
Figure 20. Distribution of total dissolved solids in ground water at
depths of 200 to 300 feet (manually contoured).
45
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VARIABLE CONTOUR INTERVAL
AS SHOWN, mg/l
Figure 21. Sixth degree trend surface for total dissolved solids in
ground water at depths of 101 to 300 feet.
46
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Contour Interval 200mg/l,
Figure 22. Fourth degree surface for sulfate in ground water
at depths of 101 to 300 feet.
47
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above. Minimum sulfate concentrations are associated with recharge entering
the Valley from the north and northwest. Both the TDS and sulfate trends are
indicative of minor inflow from the northwest flank of Sunrise Mountain. In-
flow from the west, southwest, and south, particularly the latter, is enriched
in sulfate with the result that most of the ground water in Paradise Valley
does not meet the U.S. Public Health Service (1962) standard.
Nitrate and chloride trend surfaces had the lowest coefficients of
correlation, indicating numerous local variations are present in comparison
to broad, valley-wide trends for the parameters previously discussed. In
general, the shallow aquifer, as defined by Maxey and Jameson (1948) at depths
of 250 to 450 feet, contains 5 mg/& or less nitrate. It is probable that
wells in the depth range of 101 to 300 feet with greater than 5 mg/£ nitrate
are either producing (in part) from the upper portion of the saturated zone
and/or there is leakage along the casing. Data to check these possibilities
were not available for all wells in question.
Distribution of chloride in ground water for the interval from 101 to
300 feet is also poorly described by the trend surfaces. As in the case of
nitrate, numerous local variations are superimposed on the first order,
regional trend (Figure 23). The latter depicts a concentration gradient of
approximately 10 mg/& per mile. Actual concentration in the southeast and
northwest corners of the study area are 185 and 10 mg/&, respectively. The
low concentrations of chloride suggest prime recharge to the alluvial fill
comes from source area(s) low in chloride and is characterized by short resi-
dence time, or relatively short flow paths, or both. This in turn, suggests
that recharge to the valley fill may also be associated with movement in the
carbonate aquifers rather than only in the alluvial aprons flanking the
carbonates.
It is apparent from the first order chloride trends (Figure 23) that
absolute concentrations at any point and concentration gradients across the
Valley are very dissimilar for the three depth intervals considered. Markedly
more saline conditions prevail in the interval from -0 to 100 feet and largely
reflect natural conditions, primarily concentration by evapotranspiration and
the presence of saline soils. Both influences are - apparent in the interior
portion of the Valley characterized by shallow depths to ground water, phreato-
phytes, and fine-grained playa facies sediment types. However, man-related
factors such as waste disposal are also operative and are dominant influences
in the eastern part of the Valley.
In terms of water quality, the depth interval from 51 to 100 feet can be
considered as transitional. This, plus the scarcity of data points (as re-
flected in Figure 24), justifies discussion of this zone in conjunction with
the overlying and underlying intervals.
SHALLOW GROUND-WATER QUALITY (depth interval 0 to 50 feet)
Effects of Soil and Runoff
Water quality in the near surface zone within the study area is generally
poor. The salts present are a result of concentration by evaporation and
transpiration from areas with a high water table and former marshy areas,
48
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rt KQAD i
LIMIT OF
DATA
0 to 50 FEET
LIMIT OF } LIMIT OF DATA.?
DATA FOR S • FOR 51 to 100 FEET
101 to 3004L
FEET 3*
OloSOfeel deplh; contour inlerva! K)0
SMolOOfeet depth; contour interval 500
mg/l
I0lto300 feet depth; contour interval
50 mg/l
Figure 23.. First degree trend surface for chloride in ground water
at depths of 0 to 50, 51 to 100, and 101 to 300 feet.
49
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Figure 24. Locations of wells used to characterize ground-water
quality at depths of 51 to 100 feet.
50
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streams, and possibly shallow lakes or ponds. Dissolution of the valley fill,
sulfate in particular, is also a contributor. Sulfate in the form of gypsum
is abundant in the Mesozoic sediments in the southern end of the Spring Moun-
tains and in the Sunrise Mountain and Rainbow Garden areas to the east.
Urbanization and associated lawn watering plus limited agricultural develop-
ment have leached the salts in the soil profile directly as a result of
return flows or indirectly as a result of a rising water table. The latter
phenomenon is most pronounced in the vicinity of Las Vegas Wash. Definition
of the effects on ground-water quality due to modifications in soil profiles,
greatly increased return flows from irrigation water, and altered runoff
patterns associated with developed versus undeveloped areas was not possible.
However, a general understanding of probable influences merits discussion.
An indication of the role soil conditions should have on surface water
and shallow ground-water quality can be seen by comparing the distribution
and characteristics of major soil groups (see Figure 25 and Table 2) as
defined by Langan et al. (1967). The major soil associations reflect dis-
tinctive landscape forms, parent materials, and patterns of individual soil
types. For example, the Glendale-Land association is restricted to the level
or nearly level valley floor. It is moderately to well drained and capable
of supporting irrigated crops. The parent materials are primarily recently
reworked, fluvial and(or) floodplain sediments . The Badland-Bracken-McCarran
soil association, on the other hand, is derived from fine-grained sediments
associated with distal ends of alluvial fans or with former lakes or sluggish,
through-moving drainage in late Pleistocene time. Medial portions of the
fans contain very shallow, medium to coarse-grained soils underlain by well
cemented gravel or caliche. These are represented by the Cave-Goodsprings-
Las Vegas and the Tonopah-Pittman-Eastland-Jean associations. Soils in the
Skyhaven-Spring-Gass association are somewhat intermediate in character be-
tween those developed on the fans and those on playa materials. They are
fine to medium grained, relatively shallow, moderately to strongly mineraliz-
ed and locally underlain by a limey hardpan.
In summary, the floodplains of the major washes contain less saline,
very deep loamy soils. Between the dominant drainage courses are the highly
gypsiferous, deep loamy soils. These are bounded on the north by the
Skyhaven-Spring-Gass association developed on level and gently sloping
terraces consisting of loamy clayey soils and underlain by a hardpan. It is
likely under predevelopment conditions, that overland flow across the gypsi-
ferous soils on the interfluves resulted in significant salt removel.
Generally, medial portions of the alluvial fans surrounding the developed
areas of the Valley, and contributing significant runoff to urbanized areas
during intense, but localized, precipitation events, are characterized by low
infiltration rates. This is attributed to the presence of caliche and
cemented gravel hardpans. From a study of caliche development and the effects
on runoff and infiltration on the Red Rock Canyon fan, Cooley et al. (1973)
concluded that caliches on four representative physiographic units within the
fan apron as far east as 21/61-3ab have infiltration rates equivalent to
stratified or unweathered clay, i.e., essentially impervious. Throughout most
of the developed area in the Valley the native soils present severe limita-
tions on the use of septic tanks (Table 2) which is also indicative of low
permeability within five feet of the land surface.
51
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Figure 25. Map of the major soil associations in Las Vegas Valley.
52
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TABLE 2. SUMMARY OF THE CHARACTERISTICS OF MAJOR SOILS IN LAS VEGAS VALLEY*
Soil Association
Soil Nane and Characteristics
Unified
Classification
Septic Tank
Limitation
Glendale-Land "Very deep loamy soils on nearly level flcodplains" Glendale ML, GP, KxJerate-
soils constitute 60 percent of the association and are well drained, SM, CL Severe
medium textured, strongly calcareous, and moderately or slowly
permeable.
land soils constitute 20 percent of the association and are well
drained, moderately fine to medium textured, unusually high in
.crystalline salt and gypsum and moderately slowly or slowly
permeable.
Badland-Bracken- "reep and very deep, loamy and gravelly, highly gypsiferous OL/ML, CL, Severe
McCarran soils on nearly level to moderately sloping terraces and on SC, CH
eroded, moderately sloping to strongly sloping terrace escarpments"
Badland makes up about 35 percent of the association and consists
of highly gypsiferous, calcareous, lake laid silts and clay.
Bracken and McCarran soils each constitute 32 percent of the assoc-
iation and are well drained, gravelly, moderately coarse textured
and high in gypsum.
Cave-Goodsprings- "Shallow and very shallow gravelly and loamy soils on nearly SM, SC, ML, Severe
Las Vegas level and gently sloping terraces. Commonly underlain by hard- CL
pan or cemented gravel"
Cave soils constitute 35 percent of the association which
occupies 35 percent of the Valley. Cave soils are very shallow
to shallow, moderately coarse textured, and overlie a thick cal-
careous hardpan.
Goodsprings soils make up 30 percent of the association and are
shallow to shallow,medium textured and overlie a thick, calcareous
hardpan.
The hardpan underlying these soils inhibits installation of offsite
improvements and cannot be ripped. The soils are well drained but have
very shallow root zones and low water holding capacity.
Skyhaven-Spring- "Shallow to deep loamy and clayey soils on nearly level and CL, SM, Severe
Gass gently sloping terraces; shallow soils underlain by a hardpan." CH
Skyhaven soils form 50 percent of the association. These are
well drained, calcareous, moderately fine textured, and overlie
a calcareous hardpan.
Spring soils, forming 37 percent of the association, are imper-
fectly drained, moderately fine textured, high in gypsum and calcite.
Gass soils are moderately well drained, fine textured, calcareous.
Tonopah-Pittanan- "Very deep to shallot.',gravelly sandy and gravelly loamy soils on GW, GP, SM, Ifene
Eastland-Jean nearly level to strongly sloping alluvial fans; shallow soils GM, GW
underlain by a hardpan".
This association is most prominent as scattered spots on the
alluvial fans surrounding the Valley.
Tonopah soils, forming 37 percent of the association, are very
gravelly, coarse textured, calcareous, and excessively drained.
Pittroan soils form 37 percent of the association and are very coarse
textured, calcareous, and well drained.
Jean and Eastland soils each constitute 13 percent and are coarse
textured, well to excessively drained, and moderately deep over
gravelly parent material.
* Adapted from Langan et al., 1967.
The role of sheet runoff as a mechanism for removing surficial salts
from the soils is evident from Table 3 which was developed from a U.S. Geolo-
gical Survey (1972) study within the city limits of Las Vegas.
TABLE 3. AREAS SUBJECT TO FLOODING IN THE CITY OF LAS VEGAS
Zone
Description
Area
(square miles)
B
Bl
Subject to inundation by the base
(100-year) flood 8.58
Subject to inundation by the 500-
year flood, but not included in Zone A 1.36
Subject to inundation by sheetflow
which may occur at any time 26. 39
53
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Areas under Clark County jurisdiction are excluded, hence flooded areas
associated with the major washes, with the exception of Las Vegas Creek, are
not reflected in the figures shown above. The total area subject to flooding
and sheetflow in the Valley is unknown but can be estimated from the drainage
areas and projected floods for the major washes (Table 4). In terms of geo-
logic time, the Lesser, Intermediate Regional, and Standard Project Floods
and associated sheet runoff are likely to have occurred many times, thereby
removing much of the surficial accumulations of salt.
TABLE 4. PEAK DISCHARGES ASSOCIATED WITH FLOODS IN IAS VEGAS VALLEY*
Peak discharge (cfs) associated
with the following floods:
Drainage .Inter-
area mediate Standard
Drainage Course square miles Lesser Regional Project
Lower Las Vegas
Wash
Duck Creek
Flamingo Wash
Las Vegas Creek
1,571
1,510
1,000
807
27,000
26,500
23,000
22,000
39,000
38,500
34,000
31,500
100,000
98,000
83,000
77,500
* Taken from U. S. Army Corps of Engineers (1967).
Intense urban and suburban development in the Valley covers an area of
roughly forty square miles. Within this area many of the tributary and dis-
tributary channels have been filled in resulting in increased overland and
overstreet flood flows associated with intense, short duration storms most
common as thunderstorms in July and August. Numerous channel improvements,
particularly in certain reaches of Las Vegas Wash, Flamingo Wash, and most
recently, Las Vegas Creek have alleviated flooding problems in local areas but
a significant drainage problem remains according to Cooley et al. (1973),
Jones (1972), and the U. S. Army Corps of Engineers (1967).
At numerous locations former dry wash channels have been encroached upon
and even filled to make room for structures. Figures 26 through 29 illustrate
a typical situation where a natural wash channel has been covered with a
housing development. Overland flow from the development is at least partly
returned to the Wash, as storm sewers are nonexistent. "Improvements" of the
same channel in the downstream direction can be seen from comparing Figures
27 and 28, taken west and east, respectively, where the Wash crosses Eastern
Avenue. Note the drastic reduction in channel capacity between the natural
and "improved" state. To allow more development, land has been leveled on
either side of the "improved" channel (see Figures 28 and 29). The channel
has been completely filled in preparation for construction of another develop-
ment still further downgradient.
With the exception of areas underlain by thick, competent caliche at
very shallow depths, construction of areally extensive housing tracts, is
54
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Figure 26. Photograph of an unimproved wash channel in the
vicinity of Harmon and Eastern Avenues. Note that the subdivision in
the background straddles the wash.
Wash channel
Eastern Avenue
Figure 27. Photograph of an unimproved wash channel immediately
west of Eastern Avenue and south of Rochelle Avenue.
55
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Leveled for
development
Fill
Figure 28. Photograph of the dry wash in Figure 27 showing channel encroach-
ment as a result of fill operations in the area east of Eastern Avenue and
south of Rochelle Avenue. Note the reduction of floodplain by earth fill.
Leveled land
-
Wash channel
'
Figure 29. Terminus of the wash shown in Figures 27 and 28 in a proposed
housing development. Note the absence of stream channel in the
leveled land and the lack of a culvert beneath the street.
-------
preceded by deep leveling and grading (Figure 30) to provide proper gradients
for sanitary sewers and storm runoff and to remove expansive soils laden with
mirabilite and thenardite that are damaging to foundations. After construc-
tion the subsequent development becomes an area of recharge due to return
flows from irrigation. Patt (1977) has shown that annual recharge from such
areas is on the order of 6 to 11 acre feet per acre.
ORIGINAL LAND SURFACE
LAND LEVELED FOR DEVELOPMENT
-,^- -'.-
Figure 30. Photograph showing typical soil excavation and land
leveling in preparation for constuction of a subdivision.
To summarize, rapid urban and suburban growth in Las Vegas Valley for
about thirty years has involved consistent disruption of natural drainage
paths and associated salt flux processes in the native soils. For overland
and open channel flow, the net effect has been to collect and channelize flow
through urban portions, totally impede and block sheet flow, and to reduce
the discharge capacity of lesser tributaries. This has led to localization
of runoff and increased local recharge to the near surface zone. Similarly
removal of caliche layers and hardpans, together with nonpoint wastewater
return flows, increases the leaching of saline soils, and increases salinity
in shallow ground water. Increased infiltration of poor quality overland
flow and concentration of diffuse ground water in permeable sediments of
modern channels and ancestral washes is documented in tMs study using
nitrate and tritium data.
Impacts of Return Flows on Shallow Ground-Water Quality
Nitrate, chloride and TDS concentrations are particulary diagnostic of
return flows associated with urbanized portions of the Valley, areas of
sewage disposal, areas irrigated with sewage, and the industrial area at
Henderson. Detailed documentation of water use and return flows presented in
this study and by Malmberg (1965) reveal returns from sewage effluent, indus-
trial wastes, cooling water, and septic tank systems have infiltrated the
near surface aquifer.
57
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As early as 1912, effluent from the original Las Vegas sewage treatment
plant at Ninth Street and Harris Avenue was used for irrigation on the Stewart
Ranch located in the flat area now occupied by Lions Park and Fantasy Park.
Treatment plants were successively established in 1931 at 15th Street and
Harris Avenue, in 1942 at 25th Street and Harris Avenue, in 1948 at Harris
Avenue and Manning Street, and in 1956 at Vegas Valley Drive and Monson Road.
Primary effluent from the 1931 plant was used for irrigation until 1948 when
the plant closed. From 1948 to the present, effluent from the plants built
in 1948 and 1956 was used to irrigate acreage east of what is now the Winter-
wood Golf Course (L. Anton, City of Las Vegas, oral communication).
In 1955, 7,000 acre feet of effluent infiltrated in the eastern part of
the Valley. Whereas recharge to the near surface aquifer over the entire Valley
was estimated at 14,000 acre feet per year by Malmberg (1965) and about 18,000
acre feet by Patt (1977). From 1955 to 1969, water levels in the vicinity
of the Clark County Sewage Treatment Plant rose about 14.6 feet, or 1.04 feet
per year, largely as a result of the irrigation of alfalfa with sewage ef-
fluent in the surrounding area. The Soil Conservation Service noted that for
1,130 irrigated acres surrounding the City and County treatment plants, the
water table was six feet or less from the land surface in 43 percent of the
area (Stains, 1970). At the present time, there are over 5,000 acres in
the Valley being irrigated with 43,000 acre feet per year, only a third of
which is consumptively used.
Sewage effluent applied to the Paradise Valley and Winterwood golf courses
since 1960 and 1965, respectively, has caused little change in TDS, but nitrate
in shallow ground water increased to as much as 140 mg/£ at stations LW015 and
LW099. In the vicinity of the City and County sewage treatment plants, TDS
is on the order of 4,000 to 6,000 mg/£ which is not markedly different than
background in this area. Nitrate, however, is much elevated and typically
varies from 90 to 130 mg/£ in wells LG037, 060, and 128. Phosphate in the
latter is 8.8 mg/£ or approximately 88 times normal background concentration.
Sewage effluent from individual treatment plants associated with several
major hotels also contributed to nitrate concentrations in ground water.
Beginning in 1944 an Imhof tank and oxidation lagoons were used at the Last
Frontier Hotel on the Las Vegas Strip. The ponds proved to be under capacity
and thereafter until 1954 the combined effects of evaporation and infiltration
disposed of 50,000 to 100,000 gallons of effluent per day (G. B. Maxey, oral
communication). During this period and particularly after 1954, the District
Health Department noted contaminated wells in the area. The Flamingo Hotel,
built in 1947, had onsite treatment facilities and an outfall line which
allowed effluent to flow along Flamingo Raod and infiltrate and evaporate in
the desert. At the Tropicana Hotel a treatment plant was built and the
effluent was used on its nine-hole golf course. Any excess was held in de-
tention ponds at the site of the present day Paradise Hotel. Effluent from
a treatment plant constructed at the Desert Inn in 1950 was similarly used
for irrigation and filling a lake on the golf course. Effluent from the
Sands Hotel was formerly used for golf course irrigation or allowed to f^ow
to the nearby desert. Prior to 1955, effluent from an activated sludge plant
was used for irrigation of the Dunes Hotel golf course.
58
-------
Septic tanks are also believed to be a significant source of nitrate con-
tamination. By 1973 approximately 4,000 septic tank installations were known
in the Valley and contributed an estimated 1,750 acre feet per year of wastes
to the near surface aquifer (Patt, 1977).
Other miscellaneous nitrate sources include the LDS Church Farm and adja-
cent farms. Located between the City and County Sewage Treatment Plants, an
area of about 1,160 acres has been irrigated with effluent since 1957. The
sewage treatment plant at Nellis Air Force Base operated from 1940 to 1971.
Leakage from the lagoons and return flow from the nine-hole Base golf course,
which was partially irrigated with effluent until 1971, have contributed to
anomalous nitrate concentrations in the area immediately south of the oxida-
tion lagoons. This is an area that otherwise has relatively high quality
water in the upper 300 feet of valley fill.
The importance of other sources of nitrate such as fertilizers, buried
evaporites, and leaky sewer lines is poorly understood but believed to be
minor. Another source may be the oxidation of buried organic mats associated
with depostis at springs in the northwestern part of the Valley where nitrate
concentrations in shallow ground water in the last few years have gone from
less than 5 mg/£ to 450 mg/S, and are cause for concern. Detailed studies
of this phenomenon are being conducted (Patt and Hess, 1976). The effects of
livestock, horses in particular, is unknown but may be locally significant
considering that 10,000 horses are estimated in the Valley.
Because numerous sources of nitrate are or have been present, concentra-
tions in ground water were initially analyzed through use of trend surfaces
to ascertain variations for depth intervals 0 to 50, 51 to 100, and 101 to
300 feet. The second approach consisted of plotting nitrate levels equal to
or greater than 10 mg/& and comparing the results with known distributions of
septic tank and cesspool waste disposal systems and areas of sewage disposal.
In a negative fashion, the trend surfaces for nitrate (Figures 31 and 32)
proved to be rather revealing. Concentrations above 10 mg/A in the zone from
0 to 50 feet are common, particularly in the eastern part of the Valley. In
contrast, nitrate at depths of 101 to 300 feet is irregularly distributed
and generally quite low in concentration. This implies that waste disposal,
and primarily that in the eastern part of the Valley, dominates the shallow
nitrate pattern.
The threshold value of 10 mg/£ was selected to distinguish between back-
ground and polluted levels of nitrate. The value is arbitrary but conserva-
tively so because natural values average less than 5 to 7 mg/S- according to
raw data plots and trends initially generated. By determining deviations
from background and relating them to causal factors of land and water use,
conclusions can be drawn concerning the impact of septic tanks and other
sources of nitrate pollution on shallow ground-water quality.
In the course of calculating the return flows to the near surface aqui-
fer, highly detailed maps of areas served by on-site disposal facilities were
prepared by Patt (1977) from an examination of septic tank permits issued by
the Clark County Health Department. Indirect confirmation of this approach
for the period 1943-1972 was made by using aerial photographs and comparing
developed areas versus areas served by the City and County Sanitation Districts.
59
-------
Contour interval 20mq/lK
Figure 31. Fifth degree trend surface for nitrate in ground water at
depths of 0 to 50 feet.
60
-------
Contour Interval 2mg/l
Figure 32. Fourth degree trend surface for nitrate in ground water
at depths of 101 to 300 feet.
61
-------
Developed areas not served by sewers were assumed to contain septic tanks. A
generalized version of the detailed maps plus nitrate concentrations in ground
water is shown in Figure 33. Also shown are additional areas which are or
were recharged with wastewater. These areas were identified from previous
reports (Maxey and Jameson, 1948; Leeds, Hill and Jewett, 1961; Malmberg, 1965;
Boyle et al., 1969 a, b) and from interviews with local officials and hotel
personnel (see Patt, 1977). High nitrate concentrations from industrial and
sanitary waste return flows in the vicinity of the lower reach of Las Vegas
Wash are discussed separately-
It is evident that distribution of septic tank disposal systems is ir-
regular but widespread. The distribution is indicative of the suburban
sprawl, or "leapfrog" form of development which typifies surburnan growth in
Las Vegas. Numerous developments with on-site sewage disposal and either
public water supply or individual wells have been and will continue to be
common in the Valley. Although the volume of return flow from such sources
is relatively small, the water quality effects in terms of higher concentra-
tions of nitrate are readily noticeable.
In the zone from 101 to 300 feet deep, nitrate typically averages five
rag/Si or less and rarely exceeds the arbitrary limit of 10 mg/&. Slightly
higher average concentrations for the same depth zone are evident in domestic
wells in the area between Warm. Springs Road on the north and Paradise Spa to the
south. For the period from 1965 to January 1968 there are only about a
dozen values greater than 10 mg/£ for this area. Insofar as development was
minor prior to 1968, nitrate is apparently a recent addition and attributable
to the rapid proliferation of septic tanks and, possibly, horses in an area
of granular soils and a gradually declining water table. In general,
horses in the Valley are coincidentally located in areas served by septic
tank disposal systems.
Ground water in those portions of Paradise Valley east of Eastern Avenue
is generally under slight artesian head, hence return flows of any type are
unlikely to affect ground-water quality at depth. Comparison of the pre- and
post-1968 nitrate data for the central and western portions of the Valley
reveals that more recent analyses tend to be higher. The pre-1968 data are
commonly associated with nitrate sources that are now inactive. These in-
clude areas with septic tank disposal systems which were converted to munici-
pal sewer systems or areas used for sewage disposal only for a short period
as in the case of certain Strip hotels. Nitrate concentrations of 10 to 158
mg/£ associated with recent developments in the northwestern part of the
study area attest to the rapidity with which septic tank leachate appears in
ground water, probably due to faulty well seals. Thin but extensive permea~
bility barriers in the vadose zone contribute to lateral flow and surfacing.
Nitrate concentrations exceeding 10 mg/& in the interval from 0 to 100
feet are not well known. Domestic wells in this depth range were drilled in
the early 1950's to effect necessary land improvements and thereby gain title
to acreage released under the Desert Land Entry Act. Most of these wells
were never sampled or were destroyed, hence water quality data are scarce.
Wells of this type were relatively shallow and many have gone dry as a result
of heavy pumping on the west side of the City. Thus, for a variety of reasons,
limited data exist concerning very shallow water quality at depths of 0 to 100
62
-------
rn t-i
0UI U-th
"•/; V
CONCENTRATION (NO,)
SOURCES (Past a Present)
fm.-MS.AS OF ON-SITE SEWAGE
t"fll DISPOSAL
a I0to20mg/l
2lto45mg/l
A 46lolOOmg/l
a IOI mg/l or more
AREAS IRRIGATED WITH SEWAGE
- LAND DISPOSAL OF SEWAGE
FROM MUNICIPAL OR PRIVATE
STP
Figure 33. Generalized map showing the sources and concentrations of
nitrate in ground water.
63
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feet. As a result, emphasis was placed on sampling natural or man-induced
springs and seeps and installing wells that just penetrated the water table.
The locations of wells and other sampling points considered to tap shallow
ground water to depths of 50 feet are shown in Figure 34.
Water quality and head data from domestic wells 100 feet or less in
depth in 20/62-21 indicate shallow high quality water moves into this area
from the north and west. Contamination of this water by septic tank leachate,
leakage from the Nellis Air Force Base sewage treatment plant (20/62-05db),
and return flows from the Base golf course which was irrigated with sewage, is
evidenced by nitrate concentrations ranging from 10 to 90 mg/& in 11 of the
wells 100 feet or less deep and from 10 to 80 mg/£ in wells 101 to 300 feet
deep (Figure 33). Septic tanks have been in use in this area since the early
1950's. The Nellis treatment plant was active from 1940 to mid-1971 and
treated an average of 0.55 million gallons per day (MGD) from 1958 to 1971.
The impact of return flows from an oxidation lagoon providing primary treat-
ment for approximately 50,000 gallons a day (gals/day) of sewage from Lake
Mead Base, about a mile northeast of Nellis Air Force Base, is unknown.
Another closer source of nitrate is return flow from the leachfield of the
Meikle Manor trailer court (20/62-12a) which was established in 1958.
High concentrations of nitrate are common in shallow ground water beneath
areas irrigated with or receiving sewage. These include the Winterwood and
Paradise Valley Golf Courses, the alfalfa fields in the vicinity of the City
and County Sewage Treatment Plants, and the underflow of Las Vegas Wash
beginning in the reach where sewage return flows first appear. Values of
nitrate beneath such areas are variable, with averages ranging from about 40
to 80 mg/£ nitrate, several times greater than typical values associated with
domestic wells in areas of septic tanks. For this reason, nitrate polluted
ground water downgradient from Nellis Air Force Base is believed to be pri-
marily a result of return flow from the Base sewage treatment plant rather
than from septic tanks.
Nitrate data summarized in Table 5 show that, with few exceptions, concen-
trations of 10 mg/H or more in very shallow ground water are present only at
sampling points within or closely proximal to a recognizable source, usually
sewage effluent. This is particularly true for the LW series of sampling
points (springs and seeps). This association is not true for wells LG098,
100, 106, and 110 where low nitrate is present in areas with septic tanks.
Conversely, wells LG109 and 109 are in areas without septic tanks but have
nitrate well above background. Infiltration of nitrate enriched runoff from
fertilized lawns may be the source. Other sources of nitrate include direct
recharge by industrial waste (LG031) or sewage effluent (LG034, 037, 060)
and return flows area areas irrigated with sewage effluent (LG099, 129,
LW015).
Patterns of TDS distribution in ground water at depths of 51 to 100 feet
(the eastern portion of which is shown in Figure 35) and 101 to 300 feet
(Figure 21) reflect gradual enrichment eastward across the Valley and rapid
increase in the vicinity of Las Vegas Wash. This is believed to demonstrate
mainly natural influences on water quality. In contrast, both the hand-
contoured (Figure 36) and trend surface maps (Figure 37) for TDS in the in-
terval from 0 to 50 feet indicate large differences in terms of absolute :
64
-------
O SHALLOW WELL PENETRATING THE
UPPERMOST PART OF THE SATURATED
ZONE (DESIGNATED AS "LG" IN APP.2)
A SPRING, SEEPAGE, EXCAVATION, UNDER-
DRAIN TAPPING THE WATER TABLE
Figure 34. Locations of wells and springs used to characterize
ground-water quality at depths of 0 to 50 feet.
65
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TABLE 5. NITRATE CONCENTRATIONS IN SELECTED GROUND-WATER
SAMPLES AS RELATED TO NEARBY LAND USE
Sampling
Point
LW 10
LW 11
LW 12
LW 13
LW 14
LW 15
LW 19
LW 20
LW 31
LW 33
LW 39
LW 54
LW 60
LW 72
LW 34
LW 85
LW 86
LW 87
LW 88
LW 89
LW 90
LW 91
LW 92
LW 94
LW 96
LW 99
LW100
LG 30
LG 31
LG 32
LG 34
LG 37
LG 39
LG 41
LG 43
Nitrate
mg/S. NO 3*
«0.5)
(<0.90)
( 2.1)
(<6.99)
«1.47)
(17.8)
«1.17)
«0.6)
«5.01)
(27.0)
(<0.6)
<1.26)
<1.19)
( 3.0)
3.3
8.9
9.1
13.3
12.3
<0.1
29.3
3.4
<0.1
18.6
(13.2)
12.7
0.2
( 1-54)
(32.9)
«1.44)
(38.6)
(65.3)
«0.46)
«0.50)
«0.54)
Nearby
Sourcei
no
no
no
no
no
Paradise Valley
Country Club
no
no
possibly
possibly
no
no
no
no
no
no
no
yes
yes
no
yes
no
no
yes
yes
yes
no
no
yes
yes
yes
yes
no
no
no
Remarks
Golf course irrigated by sewage effluent
Lawn runoff and possibly some septic
tanks
Discharge from tile drain; area to west
may have been irrigated with sewage in
past
•
Discharge from spring or tile underdrain
Septic tanks present in area since 1950
Underdrain discharge, inflow partially
from area with septic tanks
Underdrain discharge; inflow from golf
course and grassed areas
Underdrain discharge; high nitrate
expected from a nearby golf course,
formerly irrigated with sewage
Underdrain discharge; nitrate source is
unknown
Lawn runoff and septic tank leachate
Septic tanks present in the area since
1958
Local recharge by industrial effluent
containing nitrate
n
Recharged by sewage effluent in Las Vegas
Wash
Return flow from irrigation with sewage
effluent
TABLE 5 (continued)
66
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Sampling
Point
LG 46
LG 48
LG 60
LG 98
LG 99
LG100
Nitrate
mg/il NO 3*
«0.37)
(<0.19)
(87.6)
( 0.9)
(83.2)
( 2.1)
Nearby
Sourcet
no
no
yes
yes
yes
yes
Remarks
Sewage effluent from Clark County STP
Background nitrate concentration in
return flow despite nearby septic tanks
and livestock; three other local wells
contain from 17 to 35 mg/X.
Irrigation return flow; sewage effluent
Background concentrations are unexpected
LG101
LG102
LG103
LG104
LG105
LG106
LG107
LG108
LG109
LG110
LG128
LG129
LG138
LG139
( 6.6)
( 0.57)
( 5.97)
(93.5)
( 0.47)
( 0.95)
( 1.17)
(61.7)
(43.2)
( 1-52)
91.0
9.3
40.0
52.0
possibly
no
no
yes
no
yes
no
possibly
possibly
yes
yes
no
possibly
yes
insofar as the adjacent area contains
septic tanks since the 1950's
Occasional high nitrate may be irrigation
return flow from lawns in the nearby
residential development
Rapid increase between April and Septem-
ber may be result of nitrogen fertilizer
in runoff from a nearby golf course
Background nitrate concentration is pre-
sent in the return flow despite nearby
septic tanks in use since the 1950's;
8 local wells contain 10 to 38 mg/Ji, NO
Source of high nitrate is possibly runoff
from lawns in nearby development;
recent recharge is indicated by a con-
centration of 16.4 TU in shallow
water table
Same comments as above; no tritium data
collected
Area contained septic tanks since the
early 1940's and shallow ground water
has 16.3 TU indicating some recent
recharge; lack of nitrate unexplained
Return flow from an area irrigated with
sewage effluent
Sample collected from very shallow water
table downgradient from International
Hotel golf course
Septic tanks
The values shown are from one-time grab samples except for averaged data shown in
parentheses. All chemical data are from Appendix 3.
Land use patterns summarized by Patt (1977) were examined to determine if a source of
nitrate could be identified in the immediate area (of the well or spring) or in the
area hydraulically upgradient therefrom.
67
-------
Contour Interval SOOmg/!
Figure 35. Fifth degree trend surface for total dissolved solids in
ground water at depths of 51 to 100 feet.
68
-------
Contour Interval 2000mg/l
• LG sampling point
A LW sampling point
Figure 36, Distribution of total dissolved solids in ground water at
depths of 0 to 50 feet (manually contoured).
69
-------
Contour Interval IOOOmg/1
Figure 37. Sixth degree trend surface for total dissolved solids in
ground water at depths of 0 to 50 feet.
70
-------
concentrations and pattern or regularity. The trend surface shows that min-
eralized waters occur near parallel, northwest trending highs located across
1) Paradise Valley, the Las Vegas Strip and the BMI complex, and 2) the north-
eastern portions of the urbanized area. In the western, northern, and north-
eastern portions of the study area, about 1,000 mg/£ TDS may constitute the
ambient condition. Increasing mineralization along the flow path is evident
as TDS reaches 3,000 mg/5- within a few miles. This increase is, in part, a
result of natural factors, including the presence of mineralized soils and
concentrating effects of evapotranspiration. Human influence may be indicated
by peak concentrations of TDS which occur in patterns roughly coincidental with
previous sewage disposal in the area of the Las Vegas Strip, in part of the
upper reach of Las Vegas Wash in the vicinity of old and recent sewage dispo-
sal areas or areas irrigated with sewage, and in the southeastern part of the
Valley near the BMI complex. Return flows from nonpoint urban and suburban
sources solubilize salts formerly deposited in the shallow soil profile by
discharging ground water. The magnitude of change in water quality is poorly
defined but is expected to be sizeable, particularly in the eastern third
of the Valley where saline soils are highly developed and where ground-water
levels are closest to the land surface. Presence of sanitary wastes in
Shallow ground water is already indicated by chloride and nitrate, in particular.
Chloride at depths of 0 to 50 feet (Figure 38) increases in concentration
from about fifty mg/H northwest of the urban area to between 500 and 1,000
mg/& in the upper reaches of Las Vegas Wash. Concentrations at stations
LW019,, LW020, LG031, and LG050 are noticeably higher than the regional trend
due to the presence of industrial wastewater return flows in the shallow
aquifer. From 1971 through 1973, waste discharges from the BMI complex ex-
hibited a wide range in chloride concentrations (178 to 168,310 mg/£). An
average value is difficult to define but is probably at least 5,000 mg/£ and,
therefore, well above background. This influences the concentration gradients
for chloride in the very shallow aquifer in the southeastern part of the
Valley.
UTILITY OF THE TREND SURFACE TECHNIQUE
Trend surfaces and statistics for various depth intervals proved useful
for evaluating and portraying lateral ground-water quality variations and
the degree of variability. Judgements are made in rejecting anomalous raw
data and in comparing plots of raw data to determine what order surface pro-
vides the "best fit." Effects of such judgements were apparent, as evidenced
by the increased value of the correlation coefficient derived from selected
versus raw data (Table 6). Nevertheless, if there was poor initial correla-
tion (in the case of magnesium, chloride and nitrate for the interval from
10J. to 300 feet) little change was effected in the coefficient following the
data selection procedure.
The highest correlation coefficient was generally associated with the
sixth order surface, but only in a few instances was this surface judged the
best indicator of overall trends. This decision was made on the basis of
visual comparison of various surfaces with plots of the actual data. Absolute
values of the coefficients were indicative of the order or trend, or lack
thereof, in the data.
71
-------
L • -
Boundary of / ^
areastudied/ T
| Variable contour interval shown in mg/l
Figure 38. Fourth degree trend surface for chloride in ground water
at depths of 0 to 50 feet.
72
-------
TABLE 6. SUMMBJRY OF CORRELATION COEFFICIENTS FOR THE TREND .SURFACES
Depth (feet) Surface
From To Order
0 50 1
2
3
4
5
6
51 100 1
2
3
4
5
6
101 300 1
2
3
4
5
6
Ca
.432
.672
.694
.741
.743
.744
.466
(.530)
.516
(.589)
.554
(.626)
.581
(.669)
.593
(.587)
.586
(.671)
Mg
,306
.511
.547
.660
.668
.674
.294
(.365)
.367
(.425)
.409
(.481)
.427
(.521)
.429
(.486)
.320
(.502)
Parameter
SOtt Cl
.285
(.302)
.424
(.510)
.506
(.525)
.558
(.500)
.517
(.510)
.5,99
(.581)
.469
.687
.709
.755
.760
.763
.427
(.513)
.498
(.587)
.530
(.635)
.548
(.673)
.553
(.583)
.465
(.657)
.531
(.705)
.650
(.834)
.687
(.886)
.707
(.909)
.698
(.904)
.688
(.932)
.451
.711
.829
.857
.882
.905
.375
(.377)
.434
(.440)
.452
(.468)
.466
(.477)
.480
(.474)
.327
(.039)
NO 3
.049
(.032)
.158
(.424)
.468
(.552)
.684
(.697)
.686
(.696)
.683
(.704)
.134
.249
.441
.500
.627
.651
.022
(.128)
.096
(.252)
.185
(.355)
.232
(.437)
.235
(.201)
.142
(.246)
TDS
.516
(.538)
.536
(.604)
.601
(.618)
.625
(.608)
.619
(.602)
.611
(.665)
.486
.737
.769
.785
.798
.805
.424
(.500)
.483
(.582)
.499
(.619)
.518
(.656)
.524
(.628)
.346
(.670)
Note: Numbers in parentheses derived after removing anomalous data and using
no more than one analysis per location.
73
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Several shortcomings in the use of trend surfaces and their statistics
to display ground-water quality variations were apparent. For the present
study, at least, there was an inverse relationship between the amount of data
and the "goodness of fit" for a given surface and parameter. Similar results
were reported by Rockaway and Johnson (1967) in their analysis of water level
data. For example, the interval from 0 to 50 feet had fewer data points,
generally resulting in a higher correlation coefficient compared to the inter-
vals from 51 to 100 and 101 to 300 feet. This erroneously indicated there
was greater regularity or order in the very shallow system when in fact the
opposite was true.
High data values for nitrate and chloride at depths of 0 to 50 feet were
consistently associated with sanitary and industrial wastes in the eastern
part of the Valley. Away from areas of waste disposal and for most samples
collected below a depth of 50 feet, nitrate is 5 mg/& or less and this is
considered background. Where well depths exceeded 50 feet or were unknown,
the chemical data were not used in the trend surface portrayals for the
interval 0 to 50 feet. The combination . of few data points and the associa-
tion of high nitrate in areas of waste disposal, therefore, partially account-
ed for the high (0.704) correlation coefficient for the interval from 0 to
50 feet versus only 0.246 for the interval from \01 to 300 feet. The low
coefficient of correlation for nitrate at depths of 101 to 300 feet suggests
very little variation, i.e., background conditions, whereas in the shallow
aquifer there is obviously a high positive correlation that can be attributed
to urbanization.
Another weakness clearly demonstrated by some of the trend surfaces was
that the best fit to the available data frequently had unrealistic values in
marginal areas where data were scarce or nonexistent. This even resulted in
negative values (see examples, Figure 31 and 32), which indicated failure
of the surface to "fit" the actual data. Perhaps a final problem of using the
technique was the tendency for misunderstanding the difference between a
trend surface and maps or surfaces manually contoured from real data. Where-
as both approaches showed concentration increase or decrease, trend surfaces
did not always clearly express true values and local deviations.
ANALYSIS OF TEMPORAL CHANGES IN GROUND-WATER QUALITY
Description of Study Method and Data Base
Ground-water quality data from previous studies by Carpenter (1915),
Hardman and Miller (1934), Maxey and Jameson (1948), and Malmberg (1965) were
supplemented with analyses collected during the study to determine if signifi-
cant changes had occurred with time. The chemical data, well characteristics,
and sampling locations are shown in Appendices 4 and 5, and Figure 39, respec-
tively. An unpublished survey made by L. Reed of the Desert Research
Institute to determine chemical stratification in ground water and unpublished
work for the Nevada State Engineer by Domenico and Maxey (1964) were also
referred to. The latter contained data and conclusions concerning changes
in ground-water quality in the period from the early 1940"s to 1963. Prior
to the present study, this was the only attempt to document temporal change
in ground-water quality in the Valley. From comparisons of chemical data from
1942-1944 and 1963, Domenico and Maxey (1964) concluded quality had not
74
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— DATA SOURCE
-WELL DEPTH (FEET)
DATA SOURCES
C —CARPENTER (1915)
DM- DOMENICO 8k MAXEY (1964)
DRI- DESERT RESEARCH INSTITUTE
(UNPUBLISHED DATA)
HM-HARDMAN 8 MILLER (1954)
MB-MALMBERG(I965)
MJ-MAXEY a JAMESON (1948)
LG^PRESENT STUDY (I9TO-1974);
SHOWS WELL NUMBER
O— GROUPING OF ANA'LYSES CONSIDERED
V FOR STATISTICAL TESTING
PITTMAN-
EAST LAS
N^ VEGAS
Figure 39. Locations of wells sampled between 1915 and 1972.
75
-------
deteriorated in the areas of major withdrawals but there was evidence of
deterioration in the southern and southwestern parts of the Valley-
Beginning in 1962, the District Health Department began an extensive
ground-water sampling program to ascertain the quality of public and private
potable water supplies in Clark County, with emphasis on Las Vegas Valley-
Data from this program, which was most active from 1968-1972, were ex-
tremely valuable to the present study in defining spatial variations in
water quality attributable to land and water use patterns and natural hydro-
geologic conditions.
In contrast, there are few historical data to ascertain temporal
changes. Excluding: 1) recent (1969-present) analyses from producing wells
in the Las Vegas Valley Water District and North Las Vegas well fields, 2)
water quality data collected by the Health Department, and 3) the present
study, there are approximately 412 analyses extending over the period 1921-
1967. The analyses extend over an area of 150 square miles and were collected
from wells ranging from 8 to 1,700 feet deep.
Tables 7 and 8, respectively, summarize the depth intervals sampled for
the various townships and periods of sampling for the same areas. Table 7
shows that 44 percent of historical water quality data prior to 1968 pertain
to wells of unspecified or unknown depth. Therefore, much of their scientif-
ic value is lost. Furthermore, only 2 percent of;available analyses document
very shallow water quality in the 0 to 100 foot depth interval whereas 22
percent are from wells deeper than 400 feet. The remaining 32 percent of the
analyses are from wells ranging in depth from 101 to 400 feet. In townships
21/62 and 22/62, deteriorating ground-water quality from return flows and
solution of evaporites from a rising water table are difficult to document
because there are essentially no chemical data for the unconfined aquifer.
Townships 20/60, 21/60, and 22/60 similarly are devoid of baseline water
quality data, hence changes in the system, from a multitude of causes, are
and will continue to be extremely difficult to document.
Historical records for all depth intervals are noticeably absent in
20/60, 21/60, and 22/60. The impact of this shortcoming may be substantial
considering the rapid urbanization underway in the eastern portions of 20/60
and 21/60. For 20/61, 21/61, and 22/61, data extend over a period of approxi-
mately 45 years. However, paucity of analyses makes it difficult to define
the chemical state of the system at given points or certain periods. With the
exception of 20/61, 21/61, 21/62, and 22/61, nothing is known about
historical ground-water quality prior to the 1955 to 1962 period. Since the
early 1940's sewage and industrial wastes were deliberately allowed to infil-
trate in 20/62, 21/62, and 22/62 with essentially no monitoring data.
A recognized shortcoming of the approach chosen to compare historical
trends in water quality was the comparison of wells of greatly varying depths
that, in all likelihood, tapped different aquifers. To overcome this, analy-
ses would have to be additionally segregated by well depth thereby further
reducing each sample group and, in turn, degrees of freedom.
As stated earlier, previously sampled wells were field located or sub-
stitute wells constructed to provide recent chemical data for comparison with
76
-------
TABLE 7. NUMBER AND DISTRIBUTION OF CHEMICAL ANALYSES OF GROUND WATER
FOR THE PERIOD 1912-1967 INCLUSIVE
Total
number
nf
analyses Unknown
Township
20/60
20/61
20/62
21/60
21/61
21/62
22/60
22/61
22/62
TOTAL
1912-1967 # %
12
61
67
9
124
40
NO
68
22
412
5
14
27
3
61
20
CHEMICAL DATA
39
12
181
41
23
40
33
49
41
COLLECTED
57
55
44
0-100
#
0
0
6
0
2
0
%
0
0
9
0
2
0
PRIOR TO
1
0
9
1
0
2
Well Depth Range (in feet)
101
#
3
0
16
0
10
9
1968
10
5
53
-200
%
25
0
24
0
8
18
15
23
13
201-300
#
1
0
9
5
13
1
9
3
41
%
8
0
13
55
10
2
13
14
10
301-400
#
2
14
2
0
9
6
5
0
38
%
16
23
3
7
12
7
0
9
401+
#
1
33
7
1
29
13
4
2
90
%
8
54
10
10
23
27
5
9
22
-------
TABLE 8. YEAR AND LOCATION OF CHEMICAL ANALYSES OF GROUND WATER
FOR THE PERIOD 1912-1967 INCLUSIVE
Year
1912
1926
1927
1929
1930
1931
1932
1934
1935
1938
1941
1942
1943
1944
1945
1946
1947
1951
1952
1953
1955
1956
1957
1962
1963
1964
1965
1966
1967
Sub-
Total
20/60 20/61
1 2
1
3
2
2
1
3
1
6
9
3
1
1
3
2 11
6
2
2 3
1 6
5 4
11 70
Township
20/62 21/60 21/61
1
2
3
1
1
1 2
1
3
3 6
9
1
1
4
5 3 18
7 20
7 10
329
10 2 19
24 1 15
65 8 121
21/62
2
1
14
1
2
4
2
1
6
1
3
1
9
48
22/60 22/61
3
1
1
1
2
3
2
9
14
10
4
9
9
68
22/62
1
3
5
2
1
6
3
22
TOTAL
412
78
-------
historical analyses. Pertinent data concerning both the original and sub-
stitute wells are shown in Appendix 5. There are inconsistencies in determin-
ing and reporting TDS concentrations in previous studies. This parameter was
recalculated and presented as the sum of the principal ionic constituents,
with bicarbonate expressed as carbonate, following the conversion specified
in Hem (1970). Table 9 summarizes how TDS was determined in previous studies
and how the original data are presented in Appendix 4. For consistency all
historical and recent data in this report show TDS calculated by summation,
with bicarbonate converted to carbonate.
TABLE 9. METHODS USED TO DETERMINE TOTAL DISSOLVED SOLIDS
IN PREVIOUS STUDIES
Reference
Original determination
Original value
presented in
Appendix 4 under heading;
Carpenter, 1915
Hardman and
Miller, 1934
Maxey and
Jameson, 1948
Desert Research
Institute, 1963
(unpublished
data)
Domenico and
Maxey, 1964
M&lmberg, 1965
Residue on evaporation
Residue on evaporation
Summation of dissolved
constituents without
conversion of bicar-
bonate to carbonate
Summation of dissolved
constituents without
conversion of bicar-
bonate to carbonate
Residue on evaporation
1. Analyses by U.S.
Geological Survey
reported residue upon
evaporation at 180°C
2. Analyses by Uni-
versity of Nevada, Reno
calculated total dis-
solved solids from
specific conductance and
as residue upon evaporation
Evaporation
Evaporation
Total
Total
Evaporation
Evaporation
Total
Groupings of wells in various parts of the Valley for which historical
chemical data are available are shown in Figure 39. Groups were selected
using criteria of: 1) generally similar hydrogeologic and water quality con-
ditions within each area; 2) sufficient number of wells to constitute a
minimal sample size for statistical tests; and 3) different time periods in
which changes in water quality could be compared.
79
-------
Within each areal grouping of historical ground-water quality data, the
values for TDS and chloride were analyzed for temporal change by means of two
nonparametric tests, the Mann-Whitney test and, in cases where sufficient
data were present, the Kruskal-Wallis test for one-way analysis of variance.
Nonparametric statistical techniques were chosen because of uncertainty con-
cerning the normality of the sample distribution, the sample size, and the
fact that data were not on interval or ratio scale. Detailed explanation of
the tests and their application to hydrogeo logical problems are found in
Siegel (1956) and Siddiqui and Parizek (1972) , respectively -
The Mann-Whitney test was used to evaluate whether two independent samples
of chemical data from the same general area of the Valley, but from different
time periods, belonged to the same population. A two-tailed test at the
five percent level of significance was specified and compared to the probabil-
ity associated with the test statistic, U or z. The raw chemical data are
arranged in ascending order, assigned ranks and then the latter are grouped
according to year to calculate the statistic U using either of the following:
n (n + 1)
or
n (n + 1)
U = nln2
where IL = sum of the ranks assigned to the group with sample size n
R = sum of the ranks assigned to the group with sample size n
Depending on the values for n\ and nz, either critical values of U or proba<-
bilities associated with the observed U are used to accept or reject the
null hypothesis at the preset level for <*. If the larger group (nz) exceeds
20, u is calculated as shown and then used to determine z:
U - (nln2)/2
which is almost normally distributed with zero mean and unit variance (Siegel,
1956). Tabular values of probability associated with the observed value of
z are compared with the previously set level of significance (oc= 0.05) to
accept or reject the null hypothesis.
The Kruskal-Wallis one-way analysis of variance by ranks, tests whether
k independent samples are from the same population. As in the case of the
Mann-Whitney test, the null hypothesis states the k samples are from the same
population. That is, the differences among samples are either genuine popula-
tion differences or they are chance variations likely to occur among random
samples. In the Kruskal-Wallis test, three or more groups of data are tested,
whereas the Mann-Whitney test compares two groups at a time.
80
-------
The H statistic used in the Kruskal-Wallis test is defined as follows:
12 k Ri
where R = number of samples
n. = number of cases in the jth sample
N = Z n . ; the total number of observations
j = sum of ranks in jth sample (column)
k
E = sum over the k samples (columns)
Where the k samples are from the same population or identical populations,
H0 is true. H is distributed as Chi square (x2) with N-l degrees of freedom
(df).
Significance of Test Results
Initial results of the Mann-Whitney test are presented in Table 10 for
each subarea of the Valley containing sufficient analyses for comparison
purposes. Values for TDS and chloride from previous studies were compared to
see if statistically significant changes occurred between each time period.
For the time periods and depths considered (range 8 to 1,700 feet; mean 468
feet, standard deviation 262 feet), essentially no significant change in
ground-water quality from 1912 to present is shown to have occured anywhere
in the Valley. At first glance this may demonstrate the slowness with which
a large, heavily developed ground-water reservoir exhibits change in water
quality due to a variety of stresses. It is the author's contention that
insufficient data exist to depict change and that the tests, in fact, are not
diagnostic.
In a second attempt to test the data and to reduce the shortcomings in-
herent in statistical testing with a sparse data base, larger sample sizes
were generated for the six subareas by grouping and comparing the available
chemical data for the periods 1912 to 1945 and 1962 to 1972. This grouping
is hydrologically justified in the northwest and central areas. Although the
period prior to 1946 was characterized by gradually increasing ground-water
withdrawal, overdraft did not occur (Maxey and Jameson, 1948). Recharge to
the deeper, artesian aquifers was believed to be primarily by lateral inflow
without significant vertical leakage from the shallow aquifer. Similarly,
chemical data for the period 1962 to 1972 represents different hydrologic
conditions in that overdraft conditions are believed to have prevailed
since 1946 and significantly since 1962, when 55,500 acre feet of water were
pumped. Peak pumpage of 70,000 acre feet occurred in 1973. Since 1971 there
has been a gradual decline in ground-water withdrawal by the Las Vegas Valley
Water District because Lake Mead water became more widely available with
completion of Stage I of the Southern Nevada Water Project.
81
-------
TABLE 10. SUMMARY OF THE MANN-WHITNEY TEST RESULTS TO EVALUATE
HISTORICAL CHANGES IN GROUND-WATER QUALITY
Sanpling Area: NORTHWEST
Date 1912 1934 1942 1947 1962 1968 1972
1912
1934
1942
1947
1962
1968
NS
S
NS
NS
NS
NS
NS
NS
NS
S
NS
1C
NS
NS
NS
NS
NS"
S
NS
NS
NS
NS
NS
NS
NS
NS
NS
NS
00
to
Area: CENTRAL
Area: PARADISE VALLEY
Sampling Area: SOUTH
Date " 1912 1934 1942 1947
1962 l%d 1972
1912
1934
1942
1947
1962
1968
NS
NS
NS
NS
NS
NS
NS
NS
S
NS
NS
NS
NS
NS
1912
1934
1942
1947
1962
1968
NS
NS
NS
MS
NS
NS
MS
NS
NS
NS
US
NS
SS
NS
SIS
.NS
NS
_JiS
1912
1934
1342
1947
1%2
1963
I'JiD
NS
WE
, , NS
NS
NS
re
MS
US
NS
NS
NS
NS
NS
NS
KS
NS
NS
NS
NS
NS
MS
NS
NS
NS
NS
Area: NORTHEAST
1912
1934
1342
1947
19 G2
1968
ns
US
iiS
us
KE
NS
!•£•
llM
NS
R<
KS
I2i
S
;-ss
SS
__^_
'•£,'
NS
NS
s I
Area: PITTKAN-EAKT LAS VEGAS
1912
1934
1942
1947
1962
1
1968 \
NS
NE
NS
KS
NS
KS
.
!
1
I r |
Notations "NS" and "S" indicate not significant or significant, respectively, and refer to observations for the paired year
groups considered. Blanks indicate no data or insufficient data for test. Values in the upper left and lower right of each
box refer to TDS and chloride, respectively.
-------
Results of testing for various subareas delineated in Figure 39 are
shown in Table 11. Significant change in TDS and chloride has occurred in
the northwest area. Deteriorating "water quality through time is indicated by
increased mean values of 118 and 21.2 mg/Jl for TDS and chloride, respectively.
In the central area, significant change did not occur. Despite the absence
of statistically significant change, TDS and chloride increased 83 and 11.6
mg/&, respectively. The central area has not been the locus of heavy pumping
because high yield wells are uncommon and water quality is less satisfactory
than in the main well fields to the west and northwest. Changes in ground-
water quality may be a result of induced lateral or vertical influx of poorer
quality water.
TABLE 11. RESULTS OF THE MANN-WHITNEY TEST TO DETERMINE SIGNIFICANT
CHANGE IN GROUND-WATER QUALITY FOR THE PERIODS
1912-1945 AND 1962-1972
Area
Northwest
Central
Paradise
Valley
South
Northeast
Pittman-
East Las
Vegas
Parameter
TDS
Cl
TDS
Cl
TDS
Cl
TDS
Cl
TDS
Cl
TDS
Cl
1912-1945
# samples
17
17
24
24
16
16
8
8
3
3
5
5
1962-1972 Statistic values
# samples c t c t Result*
19
19
16
16
9
9
12
12
10
10
3
3
77
83
58
57
47
42
12
2
5
7
99
99
1.19 1.28
0.36 1.28
37
37
22
22
3
3
0.572
1
S
s
NS
NS
NS
NS
NS
NS
NS
S
NS
NS
* S = Significant; NS = Not Significant; « 0.05.
With the exception of chloride in the northeast area, analyses from the
remaining four areas (Paradise Valley, south, northeast and Pittman-East Las
Vegas) showed no significant change in water quality. Considering the small
sample sizes for the northeast, the change in chloride may simply be coin-
cidental .
The general lack of significant change compared to constituent increases
in the northwest and central areas suggests only minor hydraulic response of
the shallow aquifers as a result of local and valley-wide water use patterns
through time. In general, the long term . trend in the other four areas cited
has involved reduction of artesian head due to overdraft elsewhere in the
Valley. Typically, development of single family domestic ground-water supplies
has been the rule, although in the past there was irrigated agriculture in
Paradise Valley involving both flowing and pumped wells (Maxey and Jameson,
1948). In the vicinity of East Las Vegas, a slight increase in artesian
83
-------
pressure was observed in the period 1952 to 1964 (Domenico, et al., 1964).
Marked changes in head and reversals of flow gradients between confined and
water table aquifers, as is the case in the western part of the Valley, are
not evident. Rather, the greatest hydraulic and water quality responses are
due to increased irrigation return flow and infiltration of sanitary and in-
dustrial waste representing additions to shallow ground-water storage
(Kaufmann, 1971; Westphal and Nork, 1972). An adequate number of shallow
sampling points does not exist to monitor expected changes over time.
Table 12 summarizes Kruskal-Wallis test results for TDS and chloride
concentrations in selected areas (see Figure 39). The probabilities shown
in column 5 are tabular values (Siegel, 1956) associated with the observed
value of H for two degrees of freedom. In all cases the observed values of
H with two degrees of freedom have a probability of occurrence greater than
the preset level of significance («) of 0.05. Therefore, the result was to
accept the null hypothesis that samples are from the same population, i.e.,
no significant change in ground-water quality has occurred.
TABLE 12. RESULTS OF THE KRUSKALL-WALLIS TEST TO DETERMINE SIGNIFICANT
CHANGE IN GROUND-WATER QUALITY FOR PERIOD 1944-1972
Area
Northwest
Central
South
Paradise
Valley
Pittman-
E. Las
Vegas
Years
Considered
1944-1963-
1972
1944-1963-
1972
1956-1963-
1972t
1944-1963-
1972t
1944-1963-
1972t
Parameter
TDS
Cl
TDS
Cl
TDS
Cl
TDS
Cl
TDS
Cl
H
Statistic
5.46
3.446
3.14
1.79
2.14
3.00
1.01
3.17
0.66
1.06
Probability
associated with H
V).069
,10
-------
WATER IN THIS AREA ©HSNT
H. ' /y
® -ft GENERALLY MEETS osl
/
STANDARDS EXCEPT AS NOTED
INSUFFICIENT DATA
/A/ TH/S
\ i .
WATER IS OF
UNACCEPTABLE
QUALITY AT ALL
• Analysis location; parameters
exceed those shown in the field
© Analysis location; parameters
shown are in excess
H- Hardness exceeds 500 mg.//
S- Sulfate exceeds 250mg/f
N- Nitrate exceeds
T- IDS exceeds 1000 mg/^
Figure 40. Locations of wells 101 to 300 feet deep with inferior water quality.
85
-------
A nitrate threshold of 10 mg/£ was chosen because concentrations at
depths of 101 to 300 feet are normally below 10 mg/£. Thus, although nitrate
concentrations to data rarely exceed the maximum permissible limit (45 rag/ft)
in drinking water, nitrate trends shown in Figure 40 are believed indicative
of areas where bacterial contaminants or dangerous nitrate concentrations are
most likely. This is particularly true of areas served by shallow domestic
wells and septic tank systems as in 20/61, 20/62, 21/62, and 22/61.
Hardness, sulfate and TDS are the most common parameters exceeding the
recommended levels in the Valley and are probably the result of natural fac-
tors. For example, excessive hardness and sulfate generally coincide with
the Duck Creek drainage area in Paradise Valley, an area of gypsiferous soils,
high evapotranspiration and poor to moderately permeable sediments. As
expected, wells with excessive TDS are located farther eastward, i.e., in
the downgradient position of the flow system. In 21/62, high TDS is associ-
ated either with high nitrate or is present along the extreme eastern edge of
the study area. The association with nitrate is considered indicative of
infiltrated sewage effluent and(or) septic tank leachate whereas minimal
recharge and highly gypsiferous sediments on the flanks of the Frenchman
Mountain block could account for hardness-sulfate-TDS association.
Further utility of the data bank created in the course of the study can
be seen in Figure 41 which was generalized fEom a computer generated plot of
water analyses classified as to hydrochemical facies. The hydrochemical
facies concept was developed by Chebotarev (1955 a, b, c) and utilized by
Back (1961 and 1966) and Seaber (1965) in studies of ground-water quality
in the Atlantic Coastal Plain. Briefly, 16 possible facies are identified
on the basis of relative concentration (in milliequivalents/liter) of the
principal ions expressed as a percentage of total anions and total cations
(Table 13). For example, water containing 90 percent or more of sodium +
potassium cations and 90 percent or more bicarbonate -I- carbonate anions is
defined as belonging to the sodium + potassium: bicarbonate + carbonate
facies. Chemical facies are a result of lithologic variations along the flow
path, residence time in the flow system, and changes in mineral composition
along the flow path due to solubility, ion exchange, precipitation, etc.
TABLE 13. CLASSIFICATION OF HYDROCHEMICAL FACIES
(adapted from Back, 1961 and Seaber, 1965)
Range in HCOs+COa content Range in Cl+SOij content
Anion facies (as % of total anions) (as % of total anions)
HCO3+CO3
HCOs, Cl+SOi,
Cl+SOit, HCO3
Cl+SOi*
90-100
50-<90
10-<50
0-<10
0-<10
10-<50
50-<90
90-100
TABLE 13 (continued)
86
-------
Flow line along
which water quality
changes are
considered; see
Figure 42 also =
HC03) CI4S04
Cl+SCU.HCOs
HC03,CI+SO,
CI+S04|HC03
CI+S04
CaMg
CaMg
CaMg.NaK
CaMg.NaK
CaMg.NaK
LOCATION OF CHEMICAL ANALYSIS
Figure 41. Hydrochemical facies in ground water at depths of 101 to 300 feet.
87
-------
Range in Ca+Mg content Range in Na+K content
Cation facies (as % of total cations) (as % of total cations>
Ca+Mg
Ca+Mg, Na+K
Na+K, Ca+Mg
Na+K
CH<10
1Q-<50
50-<90
90-<100
90-100
50-<90
10-<50
0-
-------
Radius of Circle Indicates
TDS(mo/|) as Follows-
0° 8°
So 2 o.
Locations of Data Points are
Shown on Figure 41.
Cations
Anions
PERCENTAGE REACTING VALUES
Figure 42. Piper diagram showing variations in ground-water quality
along a selected flow path through Las Vegas Valley.
89
-------
This involved assessment of lithologic boundary conditions and water quality1
(Kaufmann, 1971), waterlogging (Kaufmann, 1972), and combined paper analog
and digital analysis of the flow regime (Westphal and Nork, 1972).
Ground-water inflow was first estimated by Kaufmann (1971) by taking into
account the total monthly surf ace water flows into the Wash during 1970 as
well as the Wash flow at Pabco Road and North Shore Road (located at stations
LW003 and LW007, respectively). These are summarized in Figure 43. The
hydrograph separations reveal ground water enters the Wash in the reaches
above and below Pabco Road. Considering only the months when sewage effluent
demand (for irrigation) and evapotranspiration losses are minimal and correc-
ting total flow differences for other known surface water inputs, net flow
differences are attributable to ground water. Net average ground-water
return flow in the upper reach of the Wash is 3.37 MGD (10.3 acre feet per
day), much of which exits the tailing ponds. Lesser amounts are from commer-
cial irrigation with sewage, and "other" general return flow from sources
such as lawn watering or golf course irrigation. Accretion in the reach
below Pabco Road is approximately 5.67 MGD (17.4 acre feet per day) for a
total accretion of 9.04 MGD (27.7 acre feet per day). This compares well
with the value 10.68 MGD (32.8 acre feet per day) derived from a more detail^-
ed budget analysis of Westphal and Nork (1972).
1300
1200
1100
o 1000
0>
0 900
\ N --'"'N
\ *' \
\
A \
3 8°°
700
°
R 500
400
A-U.S.G.S. gaging station at Pabco Road, Henderson, Nevada
O-U.S.G.S. gaging station at North Shore Road near Boulder City,
Nevada
d —Sewage flow from the Las Vegas and Clark County sewage
treatment plants (
M
M J
MONTH
N
Figure 43. Hydrograph showing Las Vegas Wash discharge in 1970.
Recognizing that marked ground-water inflow occurs in the reach conta^n-
ing the tailings ponds, an effort was made to ascertain the flow path. The
90
-------
initial effort (Kaufmann, 1971) concluded that industrial return flow infil-
trating via the tailings ponds and ditches entered the Wash after flowing
laterally through thin (20 to 100 feet thick) and highly permeable sand and
gravel deposits. Although this was true, the subsequent modeling study
(Westphal and Nork, 1972) indicated that underlying, less permeable sediments
also were involved and 7.3 MGD (22.4 acre feet per day) of effluent infiltrat-
ed. This latter explanation is shown in Figure 44 which depicts the shallow,
saturated materials between the upper tailing ponds,and Las Vegas Wash, and
probable directions of ground-water flow. From the location of the trough
between the southern boundary and the mound, the presence of wastewaters in-
filtrating from the upper ponds is indicated as far as 2,300 feet south of
the ponds. It also appears that ground water in saturated materials down-
gradient from the mound is derived principally from percolation of effluent
from the upper ponds. Significant vertical transfer of water into low-yield
sediments must occur to satisfy the boundary conditions, aquifer characteris-
tics, and system stresses.
1800
1750
1700
1650
1600
1550
1500
1450
o
ffi
<
>
UJ
APPROXIMATE
LAND SURFACE
TOP OF X\ STEADY STATE
LOW YIELD SEDIMENTS *\\ WATERi LEVEL
HrDRAULIC POTENTIAL
IN LOW YIELD SEDIMENTS
\
2000
I
4000 Feet
Direction of Ground-Water Flow
HORIZONTAL SCALE
fr-0tT>
f /Vor/k
Figure 44. Ground-water flow system cross-section in the area
between the BMI tailings pond and Las Vegas Wash.
Variations in ground-water quality were determined with respect to
lateral and vertical position relative to Las Vegas Wash and particularly in
relation to the BMI tailings ponds and lagoons. Peak concentrations of
91
-------
chloride, nitrate, and TDS are located in areas extending from the plant
area to Las Vegas Wash as shown in Figures 45, 46, and 47. It is apparent
that pollutants have migrated extensively from the northern portion of the
plant area and from the tailings ponds. This is confirmed by tritium data,
particularly for stations LW020, LG030, and LG050.
Effects of industrial wastes on natural ground-water quality below the
lagoons and lower ponds include greatly increased sodium and chloride (wells
LG027 and LG028) compared to natural shallow ground-water quality tributary
to the Wash from the south (LG029, LG030, LG019, and LG020) and the north
(LG015 and LG016). Total dissolved salt concentrations are also noticeably
increased. Ground water below the lagoons near the plants and in the lower
ponds contains 5,000 to 32,000 mg/H TDS in contrast to 2,000 ± 500 mg/£ in
ground water free of industrial wastes as at LG015, LG016, and LG031.
At the time of the study influent to the upper ponds had a mean pH of
4.08 and increased concentrations of sodium (527 mg/£), chloride (948 mg/&)
and nitrate (102 mg/£) relative to natural shallow ground water in the sur-
rounding area. The industrial effluent contains large concentrations of TDS,
chloride, and nitrate, the latter originating as nitric acid used in ore
processing. As expected, ground-water quality in the area north of the upper
ponds is enriched in nitrate and chloride relative to background levels.
Detailed relationships between effluent quality and ground-water quality are
difficult to assess because of the lack of historical information. Tremendous
variability in the quality of water discharged during the course of the study
is apparent from analyses for stations LW022, 042, 043, and 044. Similar
variability over the last three decades can be assumed. Also unknown is the
volume of effluent discharged, the locus of discharge, i.e., upper ponds or
lower ponds, and duration of use.
The quality of ground-water discharge into the Wash is shown in Table 14.
Wells are at the depths indicated and are situated along or immediately adja-
cent to the Wash. They are arranged from left to right in the downstream
direction and are paired, i.e., LG029 and LG030 constitute a piezometer
nest, as do LG019 and LG020, etc. Wells on the southern edge of the channel
and downstream from the treatment plants contain TDS concentrations ranging
from 5,000 to 7,000 mg/JL Nitrate data for well LG037 near the Clark County
Sewage Treatment Plant indicate effluent infiltration and an increase in
nitrate in the shallow zone from background levels of 0.1 to 3 mg/£ to 130
mg/£. However, from this point downstream toward the tailings ponds, nitrate
decreases to background level (wells LG029 and LG030) and then increases
again in the vicinity of Pabco Road crossing (21/63-30c) due to : influx of
contaminated water evident in well LG020.
Further indications of high salt and nitrate loads in ground water trib-
utary to the Wash downstream from Pabco Road include analyses from obser-
vation wells (LG004 through LG007) and from dewatering wells installed in
connection with the Southern Nevada Water Project pipeline. The pipeline
crossed under the Wash near station LW004, requiring dewatering of 30 to 35
feet of sediments over a period of several weeks. At the peak of the de-
watering effort, approximately 20 to 30 MGD (61.3 to 92.2 acre feet per day)
were withdrawn from the well network. Well LG051 contained about 4,500 mg/Jl
TDS, primarily calcium, sodium, and sulfate. With increasing distance
92
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•SCALE IN MILES
•2000*- IDS
concentration
contour, 2000 mo,/1
— Locotion of gnolysis
Figure 45. Distribution of total dissolved solids in shallow ground
water adjacent to the lower reach of Las Vegas Wash.
93
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LEGEND
—1000'- Chloride
concentration contour
1000 mg/l
—Location of onolysis
Figure 46. Distribution of chloride in shallow ground water adjacent
to the lower reach of Las Vegas Wash.
94
-------
INDUSTRIAL
COMPLEX
&
SCALE IN MILES
LEGEND
^ Nitrate (as N03)
isoconcentration contour, 100 mg/l
• Location of analysis
Figure 47. Distribution of nitrate in shallow ground water adjacent to
the lower reach of Las Vegas Wash.
95
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TABLE 14. GROUND-WATER QUALITY IN THE UNDERFLOW OF LAS VEGAS WASH*
UPSTREAM
Well LG035
Depth 102 '
Cl 46
0?
^ SO 704
VD •« 4 "
tn ^
g NO 0.12
Id Na 87
M
c K n
g Ca 146
o
u Mg 96
TDS 1193
LG034
35'
427
3087
53
674
41
446
354
5352
LG036
45'
856
2754
58
751
26
488
318
5317
LG037
25'
980
3602
130
1165
30
552
353
6911
LG029
97 >
507
2678
<0.1
480
70
562
306
4811
LG030
30'
1168
3228
1.59
885
111
632
456
6753
LG016
47'
150
1837
<0. 1
<0. 1
247
25
330
215
2993
LG015
25'
239
1010
0.11
252
26
255
103
2213
LG019
60'
1180
3208
<0. 1
<0. 1
764
177
523
420
6320
LG020
21'
2339
2670
16.7
1560
46
588
269
7734
LG007
134'
1178
1950
73
689
82
585
270
5069
LG006
41'
1489
2103
89
782
83
619
302
5658
DOWNSTREAM
LG005
95'
1476
2373
36
1023
72
516
341
6130
LG004
47'
1775
2383
<0.1
875
88
724
436
6615
* Values shown from June 1971 samples. Well locations are shown in Figure 17.
-------
southward from the Wash, nitrate, chloride, potassium, and sodium increase
whereas calcium, magnesium, and sulfate decrease.
Considering these ground-water quality data, the ionic shifts in Wash
water quality in the vicinity of the tailing ponds are understandable. As
shown in Table 15, the most significant quality change by percentage is
nitrate, which is low in concentration in the channel substrate at a depth
of 42 feet or more (wells LG015, LG016, and LG017) but very high in shallow
wells adjacent to the pond area (wells LG052, LG053, LG054, and LG055).
These contained 152, 134, 168, and 116 mg/£ nitrate, respectively. A similar
comparison can be made for chloride.
TABLE 15. LAS VEGAS WASH WATER QUALITY IN THE VICINITY OF HENDERSON
Cl
S°4
P°4
N°3
Na
K
Ca
Mg
TDS
LW003*
(mg/£)
654
988
20
25
495
30
260
107
2833
Station
LW004t
(mg/£)
860
1178
16
30
591
40
324
139
3439
LW005?
(mg/Jl)
1000
1366
12
63
594
51
408
179
3909
Percentage change
LW005-LW003
LW003
+53
+38
-40
+152
+20
+70
+57
+67
+38
* Mean of 17 analyses for samples collected between February 1970 and July
1971.
t Mean of 11 analyses for samples collected between June 1970 and July 1971.
T Mean of 10 analyses for samples collected between April 1970 and July 1971.
High nitrate concentrations are characteristic of return flows from the
upper ponds and part of the lower ponds. In addition, well LG055, which is
flowing and, only 35 feet deep, contains 407 TU, indicating the influx of very
young ground water in this reach of the Wash (hydrologic significance of
tritium is discussed in detail in the following section). Further downstream,
head and tritium data from wells LG006 and LG007 indicate the spring pond
adjacent to the Wash is also fed with tritiated, nitrate rich ground water
indicative of industrial return flows.
The chemical load in Las Vegas Wash attributable to industrial waste
seepage was determined as follows: 1) direct measurement of chemical
97
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concentration and discharge, and 2) indirectly as the mass flux difference
between two adjacent stations on the Wash (Kaufmann, 1971). Stations LW029,
LW048, and LW049 were established as sampling and gaging sites to monitor
surface water flow of industrial effluent to the Wash. The remaining stations
on the Wash are, in downstream order, LW003, LW041 and LW045, and LW004 and
LW063. Calculated salt loads are shown in Table 16.
Table 17 shows effects of waste loading by comparing chemical conce'ntra-
tion and mass already in the Wash to that from other sources at three points
in the Wash (in consecutive downstream order: LW003, LW041-LW045, and LW004-
LW063). Each station is alternately considered as a "basepoint" where mass
flux is compared to mass flux at points upstream or downstream. The differen-
tial (between points in the Wash or between the Wash and the tributaries^
divided by the mass flux at the basepoint indicates the contribution from
ground-water or surface water sources tributary to the Wash in the reach con-
sidered (see also footnotes, Table 17). Using TDS for example, stations
LW048 and LW049 contributed 107,306 and 126,281 pounds per day on March 11
and 30, 1971, respectively. This represents 24 and 31 percent additions of
TDS to the Wash relative to the load present upstream from the influence area
of the tailings ponds.
Mass flux calculations show significant contributions of salts and nutri-
ent in the form of nitrate originating in the tailing ponds seepage. Consider-
ing mass flux in the Wash reach hydraulically above the ponds equal to 100
percent, additional contributions calculated for three segments (above Pabco
Road, between Pabco Road and the gravel pit, from the gravel pit) of the
reach influenced by the ponds are shown in Tables 16 and 17. In general terms,
the salt flux or loading attributable to ground water contaminated by waste-
water discharge approximately equaled that from all other sources. This
underscores the need to consider ground water in any basin water quality
management program to control pollutant discharge from Las Vegas Wash.
98
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TABLE 16. EFFECTS OF GROUND-WATER RETURN FLOWS ON WATER QUALITY AND
CHEMICAL MASS IN LAS VEGAS WASH
Date
Station
Discharge .
cfs MGDT
Concentration , mg/H
Na Cl SO.+ TDS
Chemical mass, Ibs/day
Na Cl SOu TDS
March 11,
1971*
March 30,
1971*
July 7,
197lt
LW048
049
003
041
045
048
049
003
041
045
048
049
003
004
063
029
1.231
1.38
34.149
11.903
25.154
1.399
1.703
35.95
15.02
23.03
0.68
0.773
14.33
15.508
0.972
6.17
0.796
0.892
22.07
7.693
16.256
0.904
1.1
23.22
9.70
14.88
0.439
0.500
9.26
10.02
0.628
3.99
1860
1880
483
495
526
1880
1890
464
460
500
1824
1764
618
704
704
526
2378
2437
643
646
694
2355
2359
585
596
637
2392
2408
860
1170
933
1907
2404
2141
1131
1071
1091
2409
2189
985
1009
1064
2482
2074
1432
1681
1504
1588
7794 T-
7467 J
3020
3227 >
3108 J
7735"}-
7411 J
2720
2753 "V
2934 J
7835 >
7183 J
3749
4571"}-
4037 J
5535
26337
88872
103074
31506
90016
99264
14032
47728
62522
17505
33921
118312
135540
39389
113490
127268
18796
66418
103836
63465
31892
208104
216633
38237
191090
213670
17733
110593
148362
52849
107306
555680
628595
126281
527680
586827
66464
289535
403152
184205
* Based on one set/station of discharge measurements and water samples, collected from 0900-1040H.
t Based on mean values for water quality and discharge. Two water samples and two discharge measure-
ments collected at stations LW029, LW048, LW049 whereas stations LW003, LW004, LW063 were each gaged
and sampled three times. All data were collected in the period 0930-1700H.
One MGD = 3.069 acre feet per day.
-------
TABLE 17. PERCENTAGE OF SODIUM, CHLORIDE, SULFATE, AND TOTAL DISSOLVED
SOLIDS ADDED TO LAS VEGAS WASH BY GROUND-WATER RETURN FLOWS
Date
March 11, 1971
March 30, 1971
July 7, 1971
Mean % *
t
*
Na
42
16
54
10
42
_28_
46
13
28
Cl
40
14
53
12
39
61
44
13
61
SOi,
18
4
25
12
19
36
2-1
8
36
TDS
24
13
31
11
30
46
28
12
46
Remarks
*
t
*
t
*
t
Total %
87
118
65
86
Represents mass contributions (by percentage) to the Wash by the ponds in
the reach above Pabco Road (LW003). Calculated from chemical mass loading
(Table 16) as follows:
LW048 + LW049
LW003 - (LW048 + LW049)
X 100
Represents mass contributions (by percentage) to the Wash in the reach
between Pabco Road (LW003) and Gravel Pit Road (LW041, LW045). Calculated
from chemical mass loading as follows:
(LW041 + LW045) - LW003
LW003
X 100
Represents mass contributions (by percentage) to the Wash attributable to
water exiting the Stewart Brothers gravel pit. The mass added is cal-
culated as the percentage addition to that already present in the Wash at
stations LW004 and LW063 as follows:
LW029
LW004 + LW063
X 100
100
-------
TRITIUM AS AN INDICATOR OF RETURN FLOWS
Introduction
The foregoing sections describing ground-water quality variations through
space and time are largely developed from analysis of gross chemical data. In
the lower Las Vegas Wash area, tritium data proved particularly diagnostic
of the presence of return flows. Subsequent phases of the study also utilized
this technique in the remainder of the Valley, portions of which have received
tritiated Colorado River water since 1955.
Under certain conditions, tritium, a radioisotope of hydrogen, can be a
useful tool in determining age and source of ground water. Use is made of
environmental tritium rather than artificial introduction as a tracer. Atmos-
pheric detonation of the first hydrogen bomb in March 1954, and other hydrogen
bomb tests between 1954 and 1961, in particular, introduced large quantities
of tritium to the atmosphere and subsequently to precipitation. For Las Vegas
Valley, recharge occurs primarily from precipitation in the Spring Mountains,
the Sheep and Las Vegas Ranges, and, to lesser extent, from rainfall and run-
off incident to the Valley floor. Because of relatively long travel times,
tritium in Las Vegas Valley ground water derived from recharge in mountainous
areas is absent or at background levels of less than five tritium units (TU;
one TU is equivalent to one atom of tritium in 1018 atoms of hydrogen). Tri-
tium of higher concentrations could be found in areas of the Valley where
recharge has been from infiltrated runoff, or return flow from imported
Colorado River water. Because Colorado River water has been distributed in
roughly the eastern half of the Valley since 1955, tritium is expected in
return flows from such water usage. The concentration of tritium in the
Colorado River has been significant but highly variable (< 100 to 750 TU) in
the period 1955 to 1973. Colorado River water was used as the only source
of water in the Henderson area beginning in 1942. For the remainder of the
Valley, but excluding North Las Vegas as well as western and northwestern
Las Vegas, River water was used from 1955 through the summer of 1971 for
summer peaking purposes only and at a maximum flow rate of about 57 acre feet
per day. After September 1971, the Southern Nevada Water Project (Phase I)
was completed and river water was used on a year-round basis in the eastern
part of the Valley, i.e., roughly east of Las Vegas Boulevard.
Of interest to the present study is use of Colorado River water in the
period 1955 through the summer of 1971. During this period there was rapid
growth in population and widespread introduction of tritiated river water
for use in lawn watering. Although use of such water increased greatly in
1972, effects of this usage were not recognizable within the time frame of the
study.
Because of the complex distribution system in the service area of the
Las Vegas Valley Water District and because River water was used only inter-
mittently for peaking purposes from 1955 to 1971, quantitative estimations
of the concentrations of tritium entering shallow ground-water resources is
impossible. Only Henderson and the BMI industrial complex used Colorado
River water exclusively.
101
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Certain areas of low density residential development are served by indi-
vidual domestic wells generally 300 feet or less in depth and tapping the
unconfined aquifer. Tritium is therefore not particularly diagnostic of
return flows under these conditions. Instead, nitrate was used as an indica-
tor insofar as these same areas are also served by septic tank disposal
systems. For the remaining areas of the Valley and for the bulk of the
population and water uses dependent on public water supplies, comparisons
of tritium content in ground water were made considering the probable source
of local recharge and the age of nearby developed areas which range from the
early 1940's to the early 1970's. In this manner, tritium was used to quali-
tatively assess the occurrence of recharge by irrigation return flows.
Despite the foregoing complications and limitations, tritium is diagnos-
tic of return flows under the following circumstances:
1. Tritium in ground water beneath areas served partly by Colorado
River water is indicative of return flows from irrigation and
other urban-related sources.
2. Shallow ground water in areas not served by Colorado River water
but containing higher concentrations (i.e., >5 TU) is probably
recharged by in-valley precipitation and runoff.
3. Areas served wholly by Colorado River water are expected to have
maximum levels of tritium in ground water; this assumes that dilu-
tion is comparable to other areas in the Valley.
Water Sampling Network
Locations and descriptions of all the stations sampled for tritium are
provided in Figure 48 and Appendix 6. If all of the tritium data are con-
sidered, the sampling points fall into six categories (Figure 49): 1)
Colorado River (Lake Mead), 2) deep ground water from artesian aquifers,
3) Las Vegas Wash surface flow, 4) shallow ground water adjacent to irrigated
areas in the Valley, 5) return flow from point sources tributary to Las Vegas
Wash, and 6) influents and effluents from the City and County sewage treat-
ment plants (LW027, LW034, LW061, and LW062) and localized, high volume
return flows from the BMI tailings ponds (LW032, LW048, and LW049) or in-
fluent to the upper ponds (LW022).
Some points in categories 3, 4, and 5 fit into more than one group, by
virtue of their location. For the most part, samples in category 4 are from
a variety of drains, seeps, springs, wells, and excavations throughout the
Valley. The data in category 5 are from very shallow wells penetrating the
uppermost few feet of the water table and are immediately adjacent to estab-
lished residential areas irrigated, for the most part, with River water.
Tritium in Las Vegas Valley Water
When considering source and distribution of tritiated water, it is
necessary to consider precipitation and runoff within the Valley, sources of
recharge to the deeper ground-water reservoirs, and general relations of the
Colorado River system water. Tritium rainout in the United States through
102
-------
0 -NEAR SURFACE AQUIFER (WELL
SAMPLES)
A - NEAR SURFACE AQUIFER (SPRING &
SEEPAGE SAMPLES)
Figure 48. Locations of surface water and ground-water stations
sampled for tritium.
103
-------
500
100
50
10
5
0 215
0213 02.4
"
•"•
-
-
A -SURFACE WATER (LW)
0 -GROUND WATER (LG)
0- COLORADO RIVER (LM)
"
.
••»
COLORADO R.
AND
LAKE MEAD
056
0061 °
A057 n'3'
0057 O002
0 058 ° 05g
A097
OQ93
DEEP
GROUND
WATER
A007
A002
LAS VEGAS
WASH SURFACE
FLOW
o055
A020 u
A 030
©027 Q006
0013
0007
0050
A089
A084 A095
£i /\
030
§130
054
A ^096
A060 A085
A082 A058
A 009
A086
A
A033
-017 115
O ©
A011
0035 0044
0OI8 0026
O041 o048
©042
0017
«°29
SHALLOW
GROUND
WATER
A091
0101
123
O
A087
QI05
©'02
103
£088 o l04
..100
O
O099 A
098 ,08
BIIO ©
o132
SHALLOW
GROUND
WATER
ADJACENT
TO IRRIGATED
AREAS
A032
A022 A049
A 048
027 A 062
A
~~
A034
A06I
"
.
^™"
-
"
-
-
RETURN FLOW
FROM POINT
SOURCES
TRIBUTARY
TO LAS VEGAS
WASH
500
100
50
tr
z
10
111
o
o
o
Figure 49. Tritium concentrations versus water type.
104
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1968 has been summarized by Kaufman and Libby (1954), Libby (1962), Thatcher
(1962) , Thatcher and Hoffman (1963), Stewart and Hoffman (1966) and Stewart
and Farnsworth (1968). Unpublished data since 1968 were supplied by T.
Wyerman (written communication). Concentrations in precipitation over
southern Nevada for the last decade are only approximately known. Atmospheric
tritium was first monitored at the Nevada Test Site in early 1969. In 1971
and 1972 spring peaks were about 150 TU and 90 TU, respectively, compared to
75 TU and less than 50 TU, respectively, for 1969 and 1970 (H. Classen, U. S.
Geological Survey, oral communication).
Long-term precipitation records for Las Vegas Valley indicate above aver-
age rainfall from 1912-1923 and from 1930-1941. In the intervening years,
and particularly from 1942-1971, there has been a long-term deficit in rain-
fall with noticeable positive departures from the average occurring only in
1949, 1952, 1955, and 1965. Long-term average precipitation is 4.4 inches
per year, whereas pan evaporation is about 90 inches.
Estimated local tritium rainout from 1952-1971 is shown in Figure 50.
Due to weapons testing, the largest pulse over most of the northern hemisphere
was in 1963. A second peak in 1965 was a result of above average rainfall
over much of the country, despite the reduced concentrations of tritium rela-
tive to 1963. Although large rainout pulses occurred in 1963 and 1965, they
followed over two decades of below normal precipitation in the Valley. From
1959-1963, cumulative precipitation was 5 inches below average. This deficit
increased to 8.4 inches by 1965. Therefore, except along wash channels and
in areas of ponded water, it is unlikely that rainfall of 7.96 inches in
1965 resulted in widespread, in-valley recharge.
Prior to September 1971, deep aquifers supplied the majority of water
distributed in the Valley. This is particularly true for the area west of
Main Street and in North Las Vegas. Average tritium content in the deeper,
artesian aquifers is 4.6 TU. The range for 5 samples is 4.1 to 5.1 TU and
comparable to values for Corn Creek Springs (4.8 TU) in an area of the Valley
20 miles northwest of Las Vegas, and to a composite sample of the West
Charleston well field of the Las Vegas Valley Water District (3.3 TU). The
discharge from Corn Creek Springs most likely is via conduits originating
in deep-seated carbonate strata subcropping beneath the valley fill. There-
fore, this water is regarded as "dead", i.e., not recently recharged. This
is also true for deep, artesian aquifers underlying Paradise Valley (LG093)
and Pittman (LG002) which contained 2.0 and 4.5 TU, respectively.
Relatively shallow observation wells were installed in the course of the
study along the upper reach of Las Vegas Wash (LG041, 042) and along the
main scarp through the Valley (LG043, 044, 047, 048). Tritium in these ranged
from 2.9 to 5.3 TU, indicating that recent recharge of tritiated water to the
water table at depths of 48 to 168 feet did not occur. Stations LG041 and
LG042 are within 100 feet of the Wash axis which is expected to be a locus of
recharge insofar as this reach has a depressed water table and carried flow
for practically every runoff event in the Valley. However, at another loca-
tion (LG055), bed infiltration of stormwater runoff apparently was related
to improvement of the Flamingo Wash channel upstream from Nellis Boulevard.
Before the drainage ditch was constructed, no through-flowing streams or
stream channels traversed the area. After construction of the east-west
105
-------
YEAR
1958
Year
TU*
Precipi-
tationt (mm)
Year
TU*
Precipi-
tationt (mm)
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
2.5
12
140
20
60
50
250
250
70
100
177
15
121
152
52
126
115
106
112
81
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
500
1300
900
350
200
190
130
140
100
80
37
98
28
202
49
141
28
129
109
65
Precipitation before 1952 is estimated to contain 2 to 10 TU
depending on location and local weather patterns (Kaufman and Libby, 1954;
Libby, 1961). Values from 1953 through 1971 are based on contour maps
of the U. S. including correlation with Ottawa, Canada (T. A. Wyerman,
written communication; Stewart and Farnsworth, 1968; Stewart and Hoffman,
1966; Stewart and Wyerman, 1970; Wyerman et al., 1970). Unpublished
U. S. Geological Survey data for the Nevada Test Site (H. Claassen, oral
communication) and U. S. Environmental Protection Agency data (D. Wruble,
written communication) for Las Vegas Valley were also utilized.
U. S. Department of Commerce, Environmental Data Service Records for Las
Vegas, Nevada.
Figure 50. Approximate Tritium Rainout at Las Vegas, for the period of
1952-1971.
106
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trending channel across the north quarter of 21/61-8, perennial spring dis-
charge originating in the vicinity of stations LW084, 072, 008, 009, 060, and
077 (in downstream order) and occasional flash floods flowed in the ditch.
As a result, TDS in a well 90 feet deep and located just south of the ditch
and west of Nellis Boulevard tripled in a six month period causing the well
to be abandoned in 1971 after many years use. Subsequent sampling yielded
55.5 TO, clearly indicative of recent recharge to the water table. Samples
from three of the stations cited above and located upstream from the well in
question contained from 21.9 to 35.6 TU, again indicative of the addition of
recent, tritiated return flows to the near surface aquifer and subsequent
discharge in small springs. As discussed below, some of these stations may
reflect recharge from overland flow as a result of precipitation, whereas
others with significant tritium are more likley due to irrigation return flows.
In summary, the foregoing comments concerning rainfall and runoff indi-
cate the probability of local, in-valley recharge. Attention is now directed
to what is believed to be the more significant recharge source, namely return
flows from urban irrigation and from industrial waste disposal, both of which
are closely related to the Colorado River water supply source.
Beginning in 1965, the concentration of tritium in the Colorado River
was monitored monthly at Cisco, Utah and at Imperial Dam, California. Random
samples were collected as early as 1961 and 1964 at the Cisco station and
Imperial Dam, respectively- The 1961 to 1968 data presented by Wyerman et
al. (1970) and unpublished data for 1969 to 1973 (T.A. Wyerman, written com-
munication) are summarized in Figure 51 to show average annual tritium con-
centrations in the Colorado River. Annual average tritium content at Imperial
Dam near Yuma in the last 13 years ranged from 52 to 710 TU, whereas concen-
trations in the upper basin at Cisco, Utah ranged from 141 to 1,126 TU.
The variation between the Cisco and Imperial Dam stations on the Colorado
River reflect difference in latitude, continental effects, and more impor-
tantly, transit time in the river system, which is increased because of the
major impoundments. The highest level at Cisco was in 1963 and 1964, whereas
at Imperial Dam the peak occurred in 1966-1967. Tritium in Colorado River
water distributed within the Valley since 1961 can be roughly estimated as
the straight line average of the Cisco and Imperial Dam values (T.A. Wyerman,
written communication).
From Figure 51, it is estimated that tritium in the Colorado River water
imported into Las Vegas Valley peaked at about 750 TU in 1963 and 1964, with
a uniform decline to approximately 200 TU in 1973. Concentrations in the
period 1953-1963 are little known but probably are on the order of 10 TU or
less in 1953 and early 1954. Peaks of several hundred TU may have occurred
in 1958 and 1959 followed by a second period of decline before levels reached
a maximum in 1963.
The service areas of the City of Las Vegas and Clark County Sanitation
Districts and the Las Vegas Valley Water District distribution (pressure)
zones are shown in Figures 52 and 53. Tritium in the influent to the City
and County sewage treatment plants as of June 29, 1971 was about 70 TU and
200 TU, respectively, which is indicative of the tritium concentration in
return flows at that time. This difference (70 versus 200 TU) is expected
because about one-half of the service area for the City plant was supplied
almost solely with deep well water, whereas the County plant services an area
107
-------
1500
I960
1965
1970
1973
a) Samples collected only in September and October
b) Samples collected only in August
c) Average of 9 monthly samples
d) Average of 10 monthly samples
e) Average of 11 monthly samples
f) Sample collected only in November
g) Concentration in water delivered to Southern California in
February 1960 (Libby, 1961)
Figure 51. Average annual tritium content of the Colorado River water.
largely dependent on River water or a mixture of River water and
ground water. Insofar as the Colorado River contained about 350 TU in 1971,
the concentration of 70 TU in influent to the City Sewage Treatment Plant
indicates that about two-thirds of the water delivered was ground water with
the balance from the Colorado River. For the County Treatment Plant, there
are about equal proportions of river water anc| ground water. Prior to 1971,
the approximate areas receiving river water and the volumes delivered
are shown in Figures 53 and 54, respectively. Although much more widespread
use of River water began in September 1971 as a result of the Southern
Nevada Water Project, the author believes that 1973 tritium data accurately
document ground-water conditions prior to any significant influences from
Project water. This assumption is believed justified considering the time
necessary for infiltration and migration of return flows from areas of appli-
cation to sampling points.
There is abundant evidence of tritiated Colorado River water recharging
shallow ground water in the area of the BMI complex in Henderson. Here,
tritium concentrations range from 212 to 411 TU in shallow ground water. At
least locally the shallow ground-water reservoir contains the probable upper
limit for tritium concentrations, considering original concentrations in the
Colorado River and decay of 5.5 percent per year. In other words, dilution
of return flows has been essentially nil in this area. Recharge from the
tailings ponds was estimated to be 9.3 MGD (28.5 acre feet per day) in Decem-
ber 1971, and at least 230,000 acre feet over the operating lifetime of the
complex, hence extremely high concentrations of tritium in return flows are
expected.
108
-------
VEGAS
/ //r/VV/Y ///////////
U c/ry OF
HENDERSON
Figure 52. Map of the sanitation district service areas in Las Vegas Valley.
109
-------
COLORADO RIVER WATER ONLY
t==-J- COLOR ADO RIVER WATER IN
w*"1 SUMMER; GROUND WATER FOR
BALANCE OF YEAR
PRIMARILY GROUND WATER; SOME
COLORADO RIVER WATER IN
SUMMER
,;, -PRIMARILY COLORADO RIVER
WATER IN SUMMER; GROUND
WATER FOR BALANCE OF YEAR
I8I01-L.V.V.W.D. PRESSURE ZONE
Figure 53. Approximate distribution of Colorado River water in Las Vegas
Valley Water District pressure zones from 1955-1971.
110
-------
15,000
COLORADO RIVER WATER AS % OF
TOTAL MUNICIPAL WATER USE IN
LAS VEGAS VALLEY; BALANCE
DELIVERED FROM DEEP SROUNDHWTEg,
COLOMBO RIVER WATER DELIVERY
MILLION GALLONS
I 1 1 1
1955
I960
1965
1970
B73
Figure 54. Colorado River water deliveries to Las Vegas Valley
from 1955 through 1973 (exclusive of deliveries to BMI and Henderson).
Many indications of recharge from the ponds and ditches are described by
Kaufmann (1971). For example, well LG050, which is 30 feet deep and located
essentially downgradient from the plant area, was recharged by the effluent
ditch leading from the plant area and then past station LW018 to the lower
ponds. When the effluent was rerouted to the upper ponds in early 1971, well
yield decreased sharply. The concentration of 212 TU probably reflects
slight mixing of low-level, natural ground water with infiltrated industrial
effluent. Station LW020, which contains 384 TU, is located at the terminal
end of a french tile drain field extending generally southward toward Boulder
Highway. Installed to allow farming in an area with a high water table, the
tiles now collect shallow ground water heavily contaminated with wastewater
originating in the plant area.
Tritium concentrations in ground water below and adjacent to both upper
and lower tailings ponds indicate widespread contamination. Prominent springs
(LW032, LW048, and LW049) created as a result of waste disposal contain tri-
tium concentrations of 411, 329, and 358 TU, respectively. Below the upper
pond area, which has most consistently received effluent since the early
1940's, piezometer LG013 (247 feet deep) contained 285 TU. This substantiates
one of the early modeling results of this study, i.e., contamination has
111
-------
entered the less permeable sediments beneath the shallow sand and gravel.
Contamination of the shallow, permeable sediments extends from the plant area
northward 1.8 miles and from the upper ponds northeastward 1.5 miles. The
overall area affected is about 16 square miles and consists of a swath 2 to 3
miles wide in an east-west direction and extending northward from the plant
area to Las Vegas Wash.
Springs adjacent to the ponds discharge contaminated water isotopically
similar to that from the Colorado River. Water from deeper zones along the
Wash in the reach above the ponds contains 3.9 to 5.4 TU. To the west, the
first wells showing increased tritium are in the vicinity of Duck Creek.
Well LG030, at a depth of 30 feet, has 47.1 TU whereas an adjacent flowing
well (LG029) completed in the low yield sediments at a depth of 97 feet con-
tains 3.9 TU. Thus, water discharging from depth and upgradient of the ponds,
contains essentially background tritium concentration and is unaffected by
industrial wastes. In the vicinity of the lower ponds, two deep wells
(LG017, 019) contain background levels of tritium, which may signify that
contamination in the less permeable, deeper sediments has not yet reached
the Wash.
Industrial effluents entering the Wash transform the underflow of the
Wash from older, largely natural water discharging from the Valley, to one
which is predominantly young and from the Colorado River. Water from wells
LG006, LG007, and LG055, in or near the Wash channel and downgradient from
the ponds, contains 250 to 407 TU.
Tritium concentrations in 23 shallow ground-water sampling points just
tapping the water table beneath urban and suburban portions of the Valley
also indicate that return flows are present. As expected, concentrations are
higher in the eastern half of the developed area where Colorado River water,
in various degrees of dilution with ground water, has been delivered since
1955 (see Table 18 and Figure 53). Heaviest use of Lake Mead water has been
along Boulder Highway and surrounding areas and in the downtown area (in
order, pressure zones 1810, 1845, 1960, 2055, and 2168). Shallow wells pur-
posely located within or adjacent to irrigated areas average 54.7 TU whereas
springs, seeps and underdrains sampled regardless of location contain 45.4
TU.
It is apparent from the tritium data (Table 18) that recent recharge
has occurred in the urban and suburban areas. Markedly elevated values of
125 and 166 TU characterize return flows in the downtown area and a residen-
tial development adjacent to Boulder Highway. Both areas received Lake Mead
water in the summer months from 1955-1971. Very shallow ground water beneath
Winterwood Golf Course, which is irrigated with treated sewage effl^emt from
the County Plant, contains 24.7 TU and is therefore low but of similar magni-
tude to other locations known to be irrigated with the same effleunt (e.g.,
LW015) or receiving Colorado River water (e.g., LW059, 087, 088; LG098, 100,
102, 105, 107). Station LW015 (a spring) contains 38.7 TU and 17.7 mg/£
nitrate. The probable source for the discharge of 18.8 gallons per minute
(0.083 acre feet per day) is irrigation return flow from Paradise Valley
Country Club. For the last 14 years, the course has mainly been watered
with effluent from the Clark County Sewage Treatment Plant. Spring flow in
Flamingo Wash (LW009, 060) may be recharged in part by return flows of
112
-------
TABLE 18. TRITIUM CONTENT OF SHALLOW GROUNDrWATER RECHARGED BY IRRIGATION
RETURN FLOWS FROM URBAN AND ^SUBURBAN DEVELOPMENTS
Sampling
Point
LW 009
015
059
060
084
085
086
087
088
089
090
092
094
LG 098
099
100
101
102
103
104
105
107
130
Tritium
Content
(TU)
21.9
28.7
40.6
.
23.7
35.6
22.6
13.3
98.9
41.1
125
25.4
21.1
91.8
17
24.7
30.9
166
53
45
40.1
79.1
36
55.5
Nearby source of recharge
Suburban developments and golf courses*
Paradise Valley Country Club
Flamingo Reservoir (contains Colorado
River water) ; Paradise Crest Housing
tract (served by Colorado River water)
Flamingo Wash underflow*
Stardust Country Club Golf Course
Downtown Las Vegas
11
Housing tract
Nonet
Downtown Las Vegas
Desert Inn Country Club Golf
Course; Convention Center
Sahara Hotel; nearby homes and
businesses
Nonet
Housing tract
Winterwood Golf Course
Housing tract
Housing tract
Huntridge Park homes
Housing tract
Desert Inn Country Club Golf Course
Royal Crest Rancheros homes
Southgate homes
Flamingo Wash drain ditch
Year(s)
developed
_
1960
Pre-1943
Pre-1943
Pre-1943
1965-1969
1965
1947
1965
Pre-1943
1965
1963
* Stations LW084, 009 and 060 (in downstream order) are situated on Flamingo
Wash which is the locus of springs and flowing wells and irrigation return
flow from nearby golf courses and housing tracts.
t Ground-water discharge from an uriderdrain in the basement of a department
store. Nearby recharge sources include return flow from housing tracts,
apartment houses and on-site landscaping.
113
-------
Colorado River water in that upgradient service areas are pressure zones 2168
and 2055.
Four samples of shallow ground water from observation wells just tapping
the water table in areas west of Interstate Highway-15 and adjacent to resi-
dential development contain between 9.7 and 38.8 TU. The lowest concentration
occurs in perched water at a depth of five feet beneath the Eastland Heights
residential area. This development is served by private water supply wells
and septic tank systems. Well LG108 with 16.4 TU is adjacent to a develop-
ment served almost solely with deep ground water. Therefore, local recharge
of runoff is believed to be the source of tritium. The maximum value of
38.8 TU is from a well immediately downgradient from the Charleston Estates
development which was on ground water until 1972. The elevated tritium is
indicative of either very rapid introduction of Colorado River water to return
flows or it is a result of precipitation and infiltration of overland flow.
Ground-water seepage at the intersection of the Union Pacific Railroad
and Bonanza Road (LW096) contains 38.3 TU compared to 9.5 TU in another seep
(LW095) at the junction of Lake Mead Boulevard and Interstate Highway-15.
Both sampling points are in or immediately adjacent to the 2168 pressure zone
of the Las Vegas Valley Water District; therefore, Lake Mead water mixed with
ground water has been present since 1955. There is very light residential
development in the surrounding area and minimal lawn watering.
In summary, the tritium data are indicators of in-valley recharge to
the shallow ground-water zone. Usefulness as a quantitative tool to determine
volume of recharge is generally not possible due to uncertainties with respect
to dilution, initial tritium concentrations, and timing of infiltration.
Qualitatively, the tritium results corroborate conclusions reached using
gross chemical analyses and water budget methods. More intensive tritium
sampling would be necessary to define tritium content of shallow ground water
completely removed from return flow sources or natural runoff infiltration,
and to establish the importance of in-valley recharge from precipitation,
concentrated runoff, and localized flooding. Data developed indicate that
concentrations of greater than 20 TU are likely a result of irrigation return
flows. The utility of using environmental tritium for detailed studies of
recharge will decrease with time because environmental tritium concentrations
continue to decrease due to termination of the atmospheric thermonuclear
testing. Also, radioactive decay is gradually lowering concentrations in
shallow ground water to marginally significant concentrations.
114
-------
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119
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Appendix 1. Characteristics of Selected Observation Wells
120
-------
SYSTEM FOR LOCATING DATA POINTS AND AREAS
Data points referred to in this report are identified or located by town-
ship, range, and section according to the rectangular subdivision of the public
lands. Locations are south of the Mount Diablo base line and east of the Mount
Diablo meridian. The three-part system used to locate a data point consists
of 1) the township (T) south (S) of the base line, 2) the range (R) east (E)
of the meridian, and 3) the section number. The section number is followed by
letters that indicate the quarter section, quarter-quarter section, and so on.
The letters a, b, c, d or the numbers 1, 2, 3, 4 are used to designate the
northeast, northwest, southwest, and southeast quarters, respectively. The
form incorporating letter characters is more familiar to the general user,
whereas the form employing only digits is more readily adaptable to computeri-
zed data handling techniques. The systems are interchangeable and both are
used herein, as appropriate.
A data point can be located to an area as small as 10 acres insofar as a
quarter section is 160 acres, a quarter-quarter section is 40 acres, and a
quarter-quarter-quarter section is 10 acres. For example, a well in the SVfii
NWtoE3* section 7, T.20S., R.60E. is designated 20/60-07abc or 20/60-07123.
If the data point location were only known to within 40 acres, it would be
identified as 20/60-0712. A fourth digit may be used to sequentially identify
up to nine sampling points in a given 10-acre area but this digit has no
location significance. To eliminate confusion, two digits are always used to
indicate the section involved. Thus, section seven is indicated as 07.
In addition to the system described, sampling points were also located
according to latitude and longitude down to degree, minutes and seconds
(Appendix 2).
121
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Well
LG001
002
003
OD4
Location
23/61-04dadl
22/62-Olcbal
22/62-08cbdl
21/63-14dbd3
Depth drilled/
depth cased
(feet)
48/48
•O
->
O M -P
Depth
* H - (feet)
0-48
4J ^
-------
to
s-' (d Q) § W
tl Q 6 ~
-> Q W Cn ^
1-5 > H 4-> M C 4-1
• 0 Id 0) 4-> 3 -H 0)
• 0) o in X! x: (d in
Description w.QfH>--w~— u-—
clay, cream
clay, blue; with gypsum 5.46/80/17/75
sand and gravel, medium-fine; volcanic;
with gypsum
sand, coarse, volcanic
not logged
11
gravel, volcanic; with sand, coarse-medium,
volcanic
sand, fine-medium; with gravel (20) medium,
volcanic 35.6/45/36/43
sand, fine-medium; with silt (25)
clay, beige, silty
sand, coarse, volcanic; with clay, brown, with
manganese stain
clay, brown, silty
clay, brown, silty; with clay, white
clay, reddish-brown, silty
clay, light brown, silty
clay, beige, silty; with clay, light green with
manganese stain 36.8/90/17/69
clay, cream 37.8/105/17/95
clay, beige and light green, gpysiferous
clay, beige, gypsiferous
clay, bluish-green 36.8/165/17/115
clay, brown, gypsiferous
clay, dark brown, gypsiferous 48.5/220/19/170
clay, blue, gypsiferous 38.9/250/16/234
sand and gravel, volcanic
sand, fine-medium, volcanic; with gravel
(20) medium volcanic 35.6/45/36/43
Appendix 1 (continued)
-------
Well Location
Depth drilled/
depth cased
(feet)
Perforated
Interval
(feet)
Depth
(feet) Description
-p
o
-------
Well Location
Depth drilled/
depth cased
(feet)
•0
-.
0 M -P
^ -P 0)
flj I* ILJ
*w n ^"*
PL, H —
Depth
(feet) Description
•p ^^
m § 5
•-- (fl Q)
>O Q
l-j > H 4J
13 5 5 Q)
• O O 4-1
§
s
I— I
"3
w
en
c
•H
-p
w
Wfn ^— ».
^J 1 ^^^
H C -P
o "in a>
*C ^0 ^H
0"20 21/63-31bab2
021 21/63-31ccal
ro
ui
022^ 21/63-31cca2
i
023 22/63-06dbal
024t 22/63-06dba2
20/18
40/40
22
45/45
30/30
025 21/63-07bcb2 24/24
026 21/63-07bcbl 100/91
Appendix 1 (continued)
45-57 clay, cream
57-62 clay, buff green, very adhesive
62-70 clay, blue flowing
0-20 sand, fine; with some clay 4.11/20/2/17.5
4.07/20/17.5/17.5
37-39 0-10 alluvium, disturbed
10-17 not logged
17-20 gravel, coarse, brown, composed of scoria,
basalt, and chalcedony quartz; with medium
sand (15)
20-27 sand, coarse-fine, brown; with clay (15)
27-30 clay, brown, sandy; with gravel, fine, (15)
composed of scoria, basalt, etc.
30-40 clay, hard, pinkish-brown with some manganese
stain; with clay, plastic, green
1-22 0-20 sand, brown, silty
20-22 sand, red-brown, silty
43-44 0-35 sand and gravel, volcanic
35-45 silt and gravel
1-30 0-0.5 salts, evaporative
0.5-1 transitional
1-2 sand, brown
2-6 sand, red-brown, gravelly
6-9 sand, light red-brown, silty
9-10 sand, red-brown, gravelly
10-11.5 sand, light red-brown
11.5-30 sand, red-brown, gravelly
0-24 sand and gravel, fine-medium, reddish, volcanic
11.4/21/41/10
87-90 0-37 sand and gravel, fine-medium, reddish
37-42 sand and clay, fine, maroon; with gravel (10)
medium, volcanic
-------
Well Location
Depth drilled/
depth cased
(feet)
0)
•P H
m «j
n > ^
o 1-1 -P
4-1 0) 0)
M -P 0)
o> s
TI a
Depth
(feet)
Description
^ Q In
S i-H 4-1 H
O (ti <1J 4-1 3
-I 4-1 (1) 3 O
Q) O 4-1 ij 43
A H ^^ co v-'
c
•H
CO
Cr> ^-,
•H 0)
OT 0)
fO 4-<
u -~-
(O
027 21/62-36baal
028^ 21/63-36baa2
029 21/62-26dbal
62/62
20/20
100/100
030 21/62-26dba2
031 22/62-llcbbl
30/30
63/63
032 22/62,-lldacl 155/147
Appendix 1 (continued)
6.98/26/41/16
6.16/45/17/32
5.6 /62/17/62
42-25 gravel, coarse, volcanic; with sand, medium
grain
45-58 sand, fine, volcanic; with gravel, (5) coarse
58-90 clay, brown silty 19.5/83/17/67
90-93 sand and gravel, fine
93-100 clay, brown; with sand (10) coarse grain
57-62 0-13 not logged 7.95/13/ -/O
13-25 sand and gravel, coarse, volcanic, intermixed
with cobbles
25-55 sand, medium, volcanic
55-62 siltstone, reddish-brown, sandy
1-20 0-1 sand, light brown, silty
1-5 sand, brown, gravelly
5-14 sand, light brown, gravelly
14-20 sand, brown, gravelly
95-100 0-23 sand and gravel, medium-coarse, light gray,
volcanic 7.17/15/20/11
5.79/23/0.5/11
23-30 sand, very fine, tan; with clay
30-34 sand, very fine, volcanic
34-42 gravel, medium, volcanic 4.83/34/17/34
42-100 siltstone, reddish-brown, sandy; with gravel
(10) fine, volcanic 1.17/100/17/38
27-29 0-23 gravel and sand, coarse, volcanic
23-30 sand and gravel, volcanic 5.28/30/17/30
47-62 0-30 gravel, medium, volcanic; with sand (10)
medium-fine, volcanic
30-38 gravel, medium-fine, volcanic; with sand
and silt (20)
38-63 silt; with sand (25), coarse 36.7/63/17/35
0-68 sand and gravel, volcanic 38.1/41.6/17/40
-------
•p *•"»»
Well Location
Depth drilled/
depth cased
(feet)
*U
0 M +J
ii i- rtj rt\
fc -P
^ -O Q
a & -H 4J
. 0 (T> Q)
• Q> o m
6 -1-1
Is co
Q In en ^
^ CJ -P
-P 3 -H
-------
Well Location
Depth drilled/
depth cased
(feet)
Perforated
Interval
(feet)
Depth
(feet) Description
•P —
0) E ,C
-------
41 *-
ro
vo
Q)
•P H
(0 m
Depth drilled/ o M £
depth cased & c <« Depth
Well Location (feet) ft H — (feet)
37-43
43-59
59-70
70-110
041 20/62r-32abal 67/67 61-64 0-35
35-37
37-42
42-57
57-60
60-67
042 20/62-32aba2 170/170 159-169 0-41
41-63
63-80
80-108
108-126
126-137
137-148
148-157
157-170
043 21/62-29dcdl 56/56 46-56 0-25
25-28
28-29
29-35
35-42
Description
0) 3 +3 M
m 4-> ft c -M
*-* nj 0) > w
•O Q 0 —
. Q (tf d) 4J p -H Q)
• (DO ^w ,n .n tl ^w
sandstone and conglomerate, light gray
siltstone , brown , sandy
siltstone, gray, sandy; with
(50)
siltstone , brown-tan
silt and gravel, light gray,
caliche
silt and gravel, light gray,
silt, light beige, sandy
silt, light green, sandy
clay or silt, cream and beige
silt, light gray, sandy; with
silt, light beige, sandy
clay, cream; with clay, beige
silt, beige, sandy
silt, cream, sandy
silt, light beige, sandy
silt, white, sandy
silt, tan, sandy
silt, beige, sandy
silt (50) , sandy
6.50/85/20/40
sandy
sandy
, sandy
grave 1 , coar se
siltstone, tan, sandy; with pea gravel (10)
siltstone, beige, sandy
sandstone, reddish^brown, intraf ormational ,
cemented
siltstone, beige, sandy
siltstone, light pinkish-brown, sandy; with
sand, (35) coarse grain
42-56 siltstone, beige, sandy; with gravel (10),
medium
Appendix 1 (continued)
-------
Well Location
044 21/62-29dcd2
045 21/62-19aaa
046 21/62-19aaa2
047 20/61-36dddl
048 20/61-36ddd2
$ r-l
2 2
Depth drilled/ o £ +>
depth cased
-------
Well
049
050
055t
056
057
058
059
060
061
062
063
064
065
066
067
068
069
070
071
072
073
074
075
076
077
078
079
080
081
082
tn
4J — C
_, M
-------
Well Location
Depth drilled/
depth cased
(feet)
T3
•*j
2
.2
M
0)
ft
JtaJ
?
M
0)
4J
5
^^^
4J
0)
0)
w
fn . .
^ i *- --•
C -P
•H (1)
083 21/62-03cabl
084
.093
098 21/62-08dcal
200/
25/24
to
099 21/62-09abal
26/25
100 20/61-35adal
12/11
101 21/62-21cdal
Appendix 1 (continued)
31/30
log available from DWR
ii
not logged
23-24 0-2 silt, sandy
2-3 soil, organic
3-4.5 caliche
4.5-8 clay, sandy
8-11 silt, clayey
11-12 sand
12-14 clay
14-14.5 sand<|>
14.5-17 clay
17-17.5 sand4>
17.5-21 clay
21-25 sand<}>
24-25 0-1 clay, silty
1-3.5 sand, silty
3.5-5 clay
5-18 sand, silty
18-20.5 gravel, sandy, calcareous
20.5-26 sand<}>
10-11 0-2.5 fill
2.5-7 clay, silty
7-8 sand, medium
8-8.5 clay, silty
8.5-11 sandtj)
11-12 clay, sandy
29-30 0-5 sand, silty, grading downward to sandy silt
with calcareous gravel
5-11.5 clay, gypsiferous in upper portion
11.5-14 clay, sandy with caliche gravel
-------
OJ
tJ
(0 (Q
Depth drilled/ ° $} ^
..depth cased «j c »S Depth
Well Location (feet) ft H -' (feet)
14-15.5
15.5-26.5
26.5-27
27-28
28-30.5
30.5-31
102 21/61-02bacl. 20/17 16-17 0-4
4-9
9-11.5
11.5-14.5
14.5-15
15-16
16-20
103 21/61-Olcacl 10/9 8-9 0-4.5
4.5-7.5
7.5-10
104 21/61-13bbcl 8/7 6-7 0-3
3-3.5
3.5-6
6-8
105 21/61-23dabl 36/35 34-35 0-5.5
5.5-11.5
11.5-20
20-23
23-25.5
25.5-26
26-27
27-28
28-28.5
28.5-33
33-34
appendix 1 (continued) 34-3€
Cn
•P ~ C
5 A '""I
0) P +J M
IM -P QJ ti 4J
*•* id
clay
-------
U)
•c
flj (d
Depth drilled/ £ g +[
depth cased S-H(D
Si-t-PO)3Oin(U
_ •j^. • HI O >H JH •£< H> 'H
Description W.QE-I-- w^o~--
sand
silt, sandy
caliche
silt, sandy
caliche
caliche, friable
caliche
clay
caliche
clay
clay, silty, with calcareous gravel<|>
clay, sandy
silt, sandy
caliche conglomerate
silt, sandy
caliche
clay
clay, silty with 6 to 8 inch thick sand and
gravel lensestj)
fill
silt, sandy, gypsiferous
gravel , calcareous
caliche conglomerate
silt, sandy, with calcareous gravel
clay
limestone conglomerate
silt, sandy, with calcareous gravel(|>
silt, sandy, with caliche gravel
caliche
sand, silty, with calcareous gravel
clay, silty
Appendix 1 (continued)
-------
Ui
Well
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
Depth drilled/
depth cased
Location (feet)
20/61-33cdbl
21/62722bba
20/60-24aaa
19/60-2 3bbc
19/60-27aab
20/62-19cab
20/62-19bbb
20/61-13adb
20/62-04add
20/61-04add
22/61-12bbb
20/61'-19bba
20/61-33cca
20/61-35cbb
21/61-04dacl
35/21
312/312
560/
605/
200/200
289/289
300/300
800/800
900/900
295/295
226/
46 O/
650/
•a
*-*
O & +•>
(4*1-44-1 1-1 C -P
• o
-------
Ul
Well
125
126
127
1-28
129
130
131
132
133
134
135
136
137
138
139 x
140
Depth drilled/
depth cased
Location (feet)
21/61r-04dac2
20/61-18bcc
20/61-29cbc
21/62-15ccb
20/61-30ddb
21/62-08aad
19/60-2 3add
20/60-1 9dca
20/61-31abal
2 1/61-3 Iaba2
20/62-21cdal
21/62-Q8dcal
21/61-12cdb
21/61-10addl
20/60-19dbbl
19/60-2 3aabl
810/
500/500
600/
30/30
10/10
90/
90/
5/5
91/90
20/19
215/
100/
375/
6/
17/
208/
*J ~ C
Cn ~
£| 5) 0) JSH4->!-iq4->
o! ^
-------
Well Location
Depth drilled/
depth cased
(feet)
Perforated
Interval
(feet)
Depth
(feet) Description
" 1 -3
Water bearing.
§ Estimated.
00
-------
Appendix 2. Location and Description qf Water Sampling Stations
138
-------
ABBREVIATIONS USED IN APPENDIX 2
ADJ - adjacent
AK - A S K Construction Company
AP - airport
ARTES - artesian
B - Boulder
BC - Boulder City
BLDR - Boulder
BMI - Basic Management, Inc.
BTN - between
CC - country club
CCSTP - Clark County Sewage Treatment
Plant
CEN - central
CHRAL - Charleston
COMP - complete
CONV CNTR - Convention Center
COR - corner
CORTZ - Cortez
CROSS - crossing
CRS - course
CURT MAN - Curtis Manor
CUT - cutthroat (flume)
CYP - Cypress
DEPT - department
DISC - discountinued
DRI - Desert Research Institute
E - east
EFFL - effluent
EMRSN - Emerson
ESTERN - Eastern
EXPWY - expressway
FLAM - Flamingo
FRWY - freeway
GC - golf course
HARRS - Harris
HEND - Henderson
HO - hotel
HWY - highway
INFL - influent
L - lake
LC - lower crossing of Las Vegas Wash
and SNWP
LIQ - liquid
LM - Lake Mead
LN - I«ane
LOW - lower
LT - lot
LV - Las Vegas
LVBM - Las Vegas Building Materials
LVBN - Las Vegas Blvd. North
LWWD - Las Vegas Valley Water
District
LVW - Las Vegas Wash
MAT - material
MONT WARD - Montgomery Ward
MRLND - Maryland
N - north
ND - and
NLV - North Las Vegas
NO - number
OGD - Ogden
OKY - Oakey
OUTFL - outfall
P HOL ADAIR - Pot Holiday Authority
(Carlton Adair)
PRKNG - parking
PRWY - Parkway
RES - resvoir
RS - rock/sand
S - south
SAND - Sandhill
SHRA - Sahara
SNWP - Southern Nevada Water Project
SP - spring
STA - station
STP - sewage treatment plant
SUP - supper
SW - southwest
TERM - terminal
TIMET - Titanium Metals Corporation
TL and PROS - Telephone Line (Holly-
wood Blvd.) and .Pabco Roads•
TR PK - trailer park
TRIE - tributary
UP - upper
UPRR - Union Pacific Railroad
V - valley
VEHCLS - vehicles
W - Valley View
W - West
WINTRWD, WW - Winterwood
WY - way
139
-------
EXPLANATION OF SAMPLING LOCATIONS
DESIGNATION OF SAMPLING LOCATIONS (S. P. Designation)
The following conventions were employed in numbering sample location
and containers:
Type Sampling Point Designation
Surface water in Las Vegas LW & 3 digit number commencing
Valley with 001
Ground water LG S 3 digit number commencing
with 001
Surface water is defined in the present study to include all samples
collected from other than wells. The designation of LG (ground water)
points is therefore restricted to locations where the sample is removed
directly from the subsurface. Springs, seeps, ground-water fed streams
and various wastewater discharge points are classified as surface water
(LW) and further subdivided according to type.
SAMPLE POINT INDEX (S. P. Index)
Code Sample Point
1 Stream, river, creek
2 Lake, pond, reservoir
3 Well
4 Precipitation
5 Spring
6 Mine
7 Cave
8 Composite
9 Ditch
0 Other or unknown
A Sanitary waste (occurs as surface water)
B Industrial waste (occurs as surface water)
C Industrial wastes mixed with ground water (occurs as
ground water)
D Industrial wastes mixed with ground water (occurs as
surface water)
E Power plant cooling and blowdown water discharge
F Liquid fraction of sewage sludge
140
-------
Location
21/62-232311
21/62-234241
21/63-303411
21/63-293241
21/63-293311
21/63-281121
21/63-144111
21/61-131221
21/61-131211
21/62-314111
21/62-294343
21/62-294221
22/62-051411
22/62-043221
22/62-042331
21/62-273421
22/62-114131
22/62-021431
21/62-354141
21/62-363441
21/62-363411
22/63-072311
22/63-071221
21/62-113231
21/62-104221
21/62-222241
21/63--313131
21/63-^293325
21/63-281421
X
d>
•g
H
*
ft
W
1
1
1
1
1
1
1
1
1
5
5
5
5
5
5
A,
B
B
C
C
A
B
A
B
E
A
C
D
2
S.P. Desig
nation
LW001
002
003
004
005
006
007
008
009
010
Oil
012
013
014
015
016
017
018
019
020
021
022
023
025
026
027
028
029
LW030
Description
LAS VEGAS WASH 1
LAS VEGAS WASH 2
LAS VEGAS WASH 3
LAS VEGAS WASH 4
LAS VEGAS WASH 5
LAS VEGAS WASH 6
LAS VEGAS WASH 7
FLAMINGO WASH 1
FLAMINGO WASH 2
STEVENS SPRING
UNNAMED SPRING
GRAPEVINE SPRING
WHIT. MESA SP. 1
WHIT. MESA SP. 2
WHITNEY MESA SEEP
CLARK STA OUTFALL
STAUFFER DITCH A
STAUFFER DITCH B
LV BLDG MAT POND
HEND STP GW DRAIN
HEND STP OUTFALL
TITANIUM DITCH
BMI STP OUTFALL
NEV RS DISCHARGE
SUNRISE STA OUTFALL
CLARK COUNTY STP EFFL
BMJ SEEP PABCO-RD
GRAVEL PIT DRAIN
POND ADJ LV WASH
Lat.
360638
360614
360518
360521
360524
360556
360720
360745
360747
360437
360513
360530
360358
360314
360353
360518
360244
360351
360431
360421
360427
360308
360316
360810
360813
360646
360440
360519
360S46
Long.
1150131
1150059
1145901
1145825
1145810
1145629
1145416
1150626
1150624
1150445
1150412
1150418
1150353
1150348
1150346
1150226
1150051
1150056
1150046
1150010
1150010
1145926
1145854
1150141
1150206
1150236
1145916
1145824
1145632
Appendix 2 (continued)
141
-------
Location
20/61-363431
21/63-322341
21/62-224421
21/62-103441
22/62-021441
22/62-024321
21/63-304311
22/62-123231
22/62-123321
22/62-123232
21/63-304312
21/63-312241
21/63-312211
21/63-312221
20/62-302431
21/62-102331
21/62-354131
21/62-103442
21/62-344431
22/62-123241
17/59-341121
22/58-023321
21/62-191113
21/61-124131
21/62-103421
21/62-222221
21/63-293242
21/62-274341
21/63-281313
X
V
-d
c
H
cu
w
1
c
1
A
B
D
1
B
B
B
1
D
D
D
1
1
D
F
2
B
5
5
5
5
A
A
1
E
1
&>
•H
tn
& C
o
• -H
^
W G
LW031
032
033
034
035
039
041
042
043
044
045
047
048
049
050
051
052
053
054
055
057
058
059
060
061
062
.063
064
LW065
Description
CHARLESTON DITCH
GRAVEL PIT SEEP
TRIE TQ DUCK CREEK
LV STP OUTFALL
BMI NO. 1 (disc.)
GRAVEL PIT
LAS VEGAS WASH 9
STAUFFER EFFL 3
STAUFFER EFFL 6
STAUFFER EFFL 2
LAS VEGAS WASH 9A
BMI POND SEEP 1
BMI POND SEEP 2
BMI POND SEEP 3
E. WASH AVE DITCH
WINTRWD GC STREAM
LVBM USED WATER
LVSTP SLUDGE LIQ
LVBM NEW POND
STAUFFER CUT FLUME
CORN CREEK SPRING
BONNIE SPRINGS
FLAM RES COMP GW
FLAM WASH 3
LVSTP INFL
CLARK CO STP INFL
LVW-4 NORTH
DUCK CR AT US 93
LVW ABOVE LW030
Lat.
360934
360453
360610
360748
360352
360303
360518
360247
360243
360246
360516
360459
360507
360511
361052
360757
360427
360748
360422
360245
362620
360312
360653
360810
360840
360718
360531
360506
360545
Long . ,
1150630
1145825
1150154
1150218
1150046
1150106
1145850
1150032
1150031
1150039
1145856
1145922
1145924
1145928
1150532
1150245
1150043
1150114
1150149
1150028
1152120
1152712
1150457
1150611
1150225
1150243
1145825.
1150200
1145636
Appendix 2 (continued)
142
-------
Location
X
0)
•o
c
H
i
A
CO
S.P, Desig-
nation
D6 script ion
Lat.
Long.
.1 , -
21/62-363442
22/63-071111
23/64-094311
23/64-094312
21/62-^053221
21/63-313313
21/61-131231
21/63-312222
21/62-191114
21/62-191li5
21/62-222421
21/62-072411
21/62-092231
20/61-263221
20/61-273431
20/61-294431
20/61-312141
21/63-281313
21/61-14142
20/61-263311
20/61-263312
21/61-02111
21/61-01211
20/61-34131
21/61-10331
21/61-20114
21/61-09111
21/61-14223
20/61-22421
A
A
A
A
1
D
1
D
5
5
4
9
9
9
9
9
9
1
5
5
5
5
5
5
5
5
5
5
5
LW066
067
068
069
070
071
072
073
074
075
076
077
078
079
080
081
082
083
064
085
086
087
088
089
090
091
092
094
LW095
HEND STP INFL
BMI STP INFL
BC STP INFL
BC STP EFFL
FLAM WASH AT LAMB
UPPER P
-------
Location
20/61-27341
20/61-31113
20/61-34211
20/62-31341
20/61-34133
23/61-044141
22/62-013211
22/62-083241
21/63-144241
21/63-144242
21/63-281311
21/63-281312
21/63-304141
21/63-293321
21/63-293322
21/63-293341
21/63-293342
22/63-053221
22/63-053222
21/63-303231
21/63-303232
21/63-311221
21/63-311222
21/63-312121
21/63-312122
21/63-313311
21/63-313312
22/62-064211
22/63-064212
X
-------
Location
K
0)
•O
G
H
•
ft
W
S.P. Desig-
nation
Description
Lat.
Long.
21/63-072322
21/63-072321
21/62-362111
21/63-362112
21/62-264211
21/62-264212
22/62-113221
22/62-114131
22/62-114132
21/62-154411
21/62-154412
21/62-222411
21/62-222412
22/62-042321
22/62-042322
22/62-042323
20/62-321211
20/62-321212
21/62-294341
21/62-294342
21/62-191111
21/62-191112
20/61-364441
20/61-364442
21/63-293323
21/62-354411
21/63-293231
21/63-293232
21/63-293233
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
LG025
026
027
028
029
030
031
032
033
034
035
036
037
038
039
040
041
042
043
044
045
046
047
048
049
050
051
052
LG053
TIMET DITCH 24
TIMET DITCH 100
BMI L PONDS W 62
BMI L PONDS W 19.5
DUCK CK AT LVW 100
DUCK CK AT LVW 30
GIBSON RD 63
STAUFFER DITCH 150
STAUFFER DITCH 45
AK UP CROSS 35
DRI UP CROSS 105
COUNTY STP 50
COUNTY STP 31
WHITNEY MESA 112
WHITNEY MESA 40
WHITNEY MESA 110
UPPER LVW 67
UPPER LVW 170
NO NAME SP 56
NO NAME SP 129
CAMPBELL RES 125
CAMPBELL RES 40
CHARLESTON BLVD 100
CHARLESTON BLVD 40
AK NO 20 LC 35
LVBM WELL WATER 20
AK LC COMP 30
AK LC-COMP 30
AK LC COMP 30
360308
360307
360506
360507
360529
360529
360253
360243
360245
360245
360703
360640
360640
360356
360354
360355
361019
361020
360514
360514
360649
360648
360933
360933
360520
360532
360525
360524
360^22
1145926
1145927
1150011
1150011
1150101
1150100
1150141
1150050
1150048
1150047
1150149
1150215
1150216
1150337
1150342
1150344
1150407
1150407
1150410
1150411
1150500
1150500
1150551
1150552
1150130
1150041
1145826
1145826
1145826
Appendix 2 (continued)
145
-------
Location
K
0)
•o
c
H
p!
•
w
S.P. Desig-
nation
Description
Lat.
Long .
21/63-293331
21/63-293324
21/62-112321
20/61-034121
20/61-154331
20/61-29333
21/62-222242
19/60-04341
19/60-09341
20/61-36222
20/62-18222
20/62-08121
20/61-03412
20/61-20311
20/61-20311
20/61-20312
20/61-28341
21/61-04211
20/61-33332
20/61-33331
20/61-34232
21/61-01221
21/62-29333
21/61-24114
21/61-24114
21/61-25313
22/61-03441
22/61-01413
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
a
3
3
3
3
3
3
3
3
3
3
3
3
LG054
055
056
057
058
059
060
061
062
063
064
065
066
067
068
069
070
071
072
073
074
075
076
077
078
079
080
LG081
AK LC COMP 30
AK NO 16 LC 30
NEV RS WASH WATER
NO 2 NELLIS AFB
NLV LOSEE WELL
NO 34 LWWD
CCSTP DEWATER
CITY LV, TULE 706
CITY LV, TULE 612
T. H. GEE 325
3115 LVBN 300
4229 LVBN 120
NELLIS AFB 350
3086 W L MEAD 665
3001 W L MEAD 300
226 ANDERSON 400
1531 W BONANZA 440
1823 W CHARL 400
2040 COLORING 425
1824 COLORING 400
UPRR NO 157, 780
2500 BLDR HWY 400
4200 E RUSSEL 404
3340 ROCHELLE 160
3360 ROCHELLE 100
5326 TOPAZ (was
coded as 5360)
7117 PARADISE 335
7044 TOMIYASU 101
360517
360521
360912
361420
361215
360946
360646
361923
361835
361025
361227
360605
361342
361144
361144
361141
361036
360928
360947
360947
361012
360926
360511
360643
360643
360526
360338
360345
1145824
1145825
1150206
1150815
1150827
1151124
1150231
1151607
1151613
1150806
1150412
1150551
1150812
1151054
, 1151046 _
1151105
1150937
1150957
1150900
1150957
1150905
1150654
1150451
1150606
1150603
1150648
1150814
1150613
Appendix 2 (continued)
146
-------
Cn
Location
c
H
W
en
a c
o
• -H
04 -M
• tti
W C
Description
Lat.
Long.
21/62-30422
21/62-03312
21/62-31133
21/62-30241
21/62-08433
21/62-09122
20/61-35144
21/62-21314
21/61-02213
21/61-01434
21/61-13223
21/61-23412
22/61-02221
21/61-26332
21/61-08134
21/61-05323
20/61-33342
20/60-24111
19/60-23223
19/60-27112
20/62-19312
20/62-19222
20/61-13142
20/62-04144
20/61-04144
22/61-12222
20/61-19441
20/61-33331
3
3
3
3
3
3
3
3
3
3
3
3
3
3
, ,. ~ 3
a
3
3
3
3
3
3
3
3
3
3
3
3
LG082
083
084
093
098
099
100
101
102
103
104
105
106
107
108
109
110
112
113
114
115
116
117
118
119
120
121
LG122
5372 SANDHILL 390
6000 E CHARLESTON 200
6100 S PEARL 600
CASEY ND SANDHILL
DILLINGHAM 25
W W GOLF CRS 26
SW 25TH ND ELM 12
BILLMAN 31
STIBOREK 20
MOTOR VEHICLE 10
PETERSON 8
JARRETT 36
ENGELSTAD 46
MCSTRAVIK 31
115 MILO WY 36
W AND OKY 39
JOSEPHS 35
CURT MAN #2, 312
7000 GILCREASE 560
RANCH SUP CLUB 605
LA PAZ TR PK 200
2343 N PECOS 289
2934 LVBN 300
NELLIS AFB #1, 800
628 W CRAIG RD 900
DAY DREAM RANCH" 600
CLUB 95, 295
716 SHADOW LN, 226
360513
360857
360443
360536
360757
360835
361008
360610
360922
360855
360738
360625
360416
360522
360817
360830
360943
361208
361750
361313
361142
361209
361248
361430
361945
360353
361133
360940
1150525
1150227
1150524
1150529
1150412
1150935
1150657
1150323
1150749
1150645
1150700
1150720
1150756
1150805
1151040
1151119
1150950
1151222
1151422
1151243
1150532
1150549
1150602
1150240
1151535
1150657
1151117
1150953
Appendix 2 (continued)
147
-------
Location
20/61-35322
21/61-044131
21/61-r044132
20/61-18233
20/61-29323
21/62-15332
20/61-30442
21/62-08114
19/60-23144
20/60-19431
20/61-304421
20/61-304422
20/62-21341
21/62-08431
21/61-12342
21/61-10144
20/61-19422
19/60-23112
21/62-28412
X
-------
Appendix 3. Chemical Analyses of Las Vegas Valley Water Samples from
February 1970 to April 1976
149
-------
EXPLANATION OF WATER QUALITY CODES
gODING CONVENTIONS
Analytical data preceded by a minus sign (-) , other than the categories
immediately below, indicate the presence of this constituent in amounts
"less than" the number shown. For example, -0.10 indicates a concentration
less than one-tenth of a milligram per liter. The following codes are also
used:
000000 analysis not regularly run for this constituent at
this sampling point
-666660 constituent in solution not fully ionized. Milli-
equivalents were not calculable.
-77777 analysis or theory indicated none of this constituent
to be present, e.g., it is chemically impossible for
bicarbonate (HCOs~) to exist in aqueous solution at
pH = 12
'-88888 analysis revealed "trace" amounts of this constituent
and was reported as "trace" by the lab
-99999 analysis usually run for this constituent at this
sampling point, but not run for this sample
SAMPLE PRESERVATION
Samples taken for nitrogen compound analysis and preserved with
mercuric chloride were coded M in the water analysis data system. All
other analyses were done on unpreserved samples unless otherwise indi-
cated- Code C indicates a seperate i sample taken for phosphorus compound
analyses and preserved with chloroform. All other analyses were done on
unpreserved samples unless otherwise indicated. In general, only surface
water samples expected to contain unstable nitrogen and phosphorus com-
pounds were preserved.
ADDITIONAL INFORMATION
The Water Analysis Data System (WADS) of the Water Resources Center,
Desert Research Institute, is well documented. Readers are encouraged to
check the appropriate references for retrieving additional data concerning
sampling and analyses that could not be put into this appendix because of
space limitation. Information concerning sample preservation, trace element
analyses, and elemental form (soluble, organic, suspended, colloidal) is
available.
150
-------
POINT IDFNTTFTEP ANf) LOCATION
*0 18 YP NUMB TE1P CON1 PH
HC03
CL
POU
NO 3
NA
CA
MG
NH<4
F OS-SUM
LG 1 NFW HFITO AP WitL 23S 61E 0* i»l<» 1
3-35-70 13 -99.0 11-M. 7.78 150 180
1-80 -.11)
7.8 135
60
31
.0
.8
678
LG 2 PITMAN ARTES WE'LL ?_?S 62E 01 321 1
3-31-70 21. 33.5 1,108 7.86 92 1,03 1353 .20 -.5 615 37 333 1,50
10-17-70 292 22.3 5196 7.67 159 766 31,07 -.10 116.0 <,2U 30 M* 1,33
1.1,
3.0
3136
it660
LG 3 PARADISE V CC
5-18-70 68 28.1.
235 63E 08 321, 1
1070 8.00 153 101
333 -.10 3.0
100
12
U3
755
LG
P HOL AOATR
21S 63E
1,31, 3
6- 7-71
9-16-71
I?- 3-71
5- 3-73
8- 3-72
1,73
775
961.
11.20
1591.
33.3
19.0
16.7
20.0
23.3
LG 5 P HOL A-CMIR 100
6- 7-71
9-16-71
1?- 2-71
5- 2-73
8- 2-72
LG 6 OLD
6- 7-71
.9
.7
33.0
875
885
910
881
871
1033
1033
1033
1001
1031,
782
787
777
71.5
771,
750
753
71,9
732
689
685
678
661
657
638
655
61,0
627
88
83
85
89
8<»
72
79
71,
78
71,
83
80
81,
89
85
88
86
86
101,
83
80
83
87
83
83
85
83
100
721,
561,
586
569
530
516
1.61,
1,1,3
1,70
1,50
619
591,
583
618
1,91,
566
672
602
596
585
51,9
530
5fc'l
535
551,
517
507
567
«»36
1,21.
(.36
«,13
MI,
31.1
31,0
31,0
333
331,
302
303
300
283
381
38*
399
301,
306
370
369
369
363
271,
367
373
275
376
.0
.0
.8
.8
.8
.0
.0
2.0
2.0
3.0
.0
.0
1.0
1.0
1.0
1.0
.9
5.1
.3
.0
.0
3.5
.1,
.it
. 1*
.6
.5
.3
1.6
1.0
1.1,
.a
.7
l.S
1.7
1.7
1.7
1.7
1.1
1.0
1.1
1.1
.7
.8
1.0
-99.0
-10.0
1.1
1.1
1.0
1.0
1.0
.1
1.0
-99.0
-10.0
61. <»6
6310
6319
6381,
6272
5983
5919
5908
5788
5917
5561
51,51
51.20
5350
5210
5183
551.5
5515
51.38
I.9I.7
1.91,3
1,803
1,887
1,965
1,913
1,919
1,900
5081
-------
POINT lOFNTTFTER AND LOCUTION
HO HA YR NU'Mn TEMP OONT PH
HC03
CL
POI» NO 3
NA
CA
MH«,
f OS-SUH
Ol
IVJ
LR q "5MMP LC 91
9-16-71 765 21.9
1?- 2-71 88? 22.2
?- 2-7? 1130 -21.7
5- 6-7? ?P56 2*. 5
7-31-7? IV!* 23.3
10-31-7? 171,3 22.2
?- 8-73 1930 -99.0
LG 10 SNWP LC 1,2
9-15-71 76U 23.9
1?- 2-71 91,8 21.1
?- 2-7? 1126 21.0
3- 2-72 1303 22.2
7-31-7? 1^55 31.7
•5- 7-73 2055 2*. 5
LG 11 AK MO 36 LC 39
9-16-71 766 21.6
12- ?-71 91,7 20.6
2- 2-72 1111 18.1
5-2-72 11,26 22.2
7-M-72 155? 21,. I,
10-11-7? 171,1 ?2.2
l-?9-73 1928 -99.0
5- 7-73 ?058 21. 1
LG 12 AK NO 37 LC 38
9-23-71 778 21.1
12- 2-71 965 19.1.
2- 2-7? 1110 17.0
5- 2-72 11.25 21.7
7-31-7? 1553 ?2.2
5- 7-73 2059 22.2
LG 13 8MI E UPPONO 250
6- 8-71 1.81. -99.9
9-16-71 767 26.0
l'-??-71 98U 23.3
?- 3-7? 111.2 '26.0
*- 2-7? 1298 26.1
5- ?-7? 11,31 27.8
8- 1-7? 1559 27.8
11- 2-7? 1765 25.6
?- 8-73 1939 23.9
5- 7-73 2069 26.?
8- 2-73 2200 29.1.
71.56
71,18
7307
8 11.1,
101.11.
121.86
9505
8075
901. 1.
8136
7580
8177
7535
6591.
6363
691.1.
6763
8387
8261.
781,1.
7269
6098
651.6
7255
751.5
8969
7259
7160
7152
7031
691.1.
6738
6576
7073
52(U
6691,
67DB
108?
21^ 63E
8.75
8.53
6.51
9.06
8.87
*.03
7.77
21S 63E
8.35
8.20
7.15
7.1,7
5.57
7.71
21S 63E
7.72
7.61
7.1,1
7.65
7.67
7,87
7.85
7 * t* Q
21S 63E
7.31
7.31
7.31
7.30
7.63
7.1,5
22S 63E
7.1,0
7.68
7.26
7.56
7.61
7.1,6
8.22
7.25
7.511
8.38
7.37
29 332 1
-77 1579
-77 1766
7 171,2
-77 2031
1,5 21,87
-77 3290
95 2193
29 332 2
1,5 1808
10 2072
51 1720
63 1633
l» 1715
39 1656
29 331, 1
11,7 1282
152 1381
178 161.8
156 1713
Hi9 2003
121 2078
111 181,7
177 1795
29 33", 2
208 1722
17,3 1630
153 1796
155 2019
150 221,2
177 1795
05 322 1
121 1532
192 11,83
91, 1517
60 11,61.
101. 11,78
150 11.1,7
?t» 11,72
108 131,3
20 11,1,2
25 11,53
156 1599
1871
1630
11,61,
1685
1887
2016
2292
191,5
2370
2015
1921
2031
1925
1600
11,56
1208
11,13
11,38
1516
1632
1251
896
1110
1301
11,68
1252
1221,
1533
1868
1807
1918
1909
1859
1878
1962
181,5
1795
1939
-.10
-.10
-.01,
-.01,
-.01,
-.10
-.10
-.10
-.10
-.01,
-.01.
-.01.
-.01.
-.10
-.10
-.01,
-.0*
-.01.
• -.10
-.10
-.01.
-.10
-.10
-.01.
-.01,
-.01,
-.01,
-.10
-.10
-.10
-.01.
-.01.
-.01.
-.01,
-.01,
-.01,
-.01,
-9.99
6.0
5.2
1.6
2.3
17.3
121.0
26. 0
.5
51.0
11,3.0
170.0
62.0
77.0
11,9.0
179.0
115.0
107.0
78.0
110.0
120.0
152.0
120.0
136.0
85.0
57.0
95.0
162.0
152.0
66.0
128.0
79.0
89.0
118.0
-.1
155.0
ii>. n
5.1.
6i>. a
831
767
690
81,5
1163
1751
960
832
1076
875
855
880
81,1
529
520
530
•558
639
615
567
71,8
506
535
617
657
793
802
1,85
568
553
520
502
511
509
1,81.
521.
515
662
161,
153
173
118
181,
21,1
175
85
88
79
77
71,
70
93
93
78
86
89
112
105
75
53
53
63
65
67
57
51
82
68
93
88
65
61,
69
67
73
85
1,88
531
523
506
",71
519
680
612
61.0
537
51,1
520
1,73
621
588
556
665
700
761,
778
515
518
503
607
689
667
1,90
700
689
686
665
681.
71.2
560
671
589
56?
596
260
276
206
283
328
309
391
325
376
301,
295
301
291,
21,9
21,6
271,
292
322
338
296
21,1,
321
313
2*7
332
305
229
299
321
306
291
300
303
303
313
291,
300
287
.0
15.0
21.6
25.0
25.0
31.7
20.0
.0
26.0
*.3
*.8
*«8
1*.0
.0
.2
1.0
1.0
1.0
.2
.2
.2
.0
.0
.0
.0
.0
.2
.0
.0
2.0
8.6
8.6
3.5
25.0
5.7
2*.0
27.0
3.5
^
!«.
-.1
-99.0
.3
-99.0
-99.0
.8
1.2
1.2
1.2
1.1
-99.0
.
-------
POIMT IOFNTTFIFR AND
MO n« YP NUMC 'TFHP
CONH
PH HC03
CL
SO*
PO*
NOT
NA
HG
NH*
F OS-SUM
Ol
U>
LG m BMI
'9-?i-7n
8- 1-7?
?- 1-73
5- 7-73
LG 15 TL
6- S-7t
9-15-71
1?- 2-71
?- 2-7?
7-31-7?
11- 1-72
2- (5-77
5- 7-73
R- 2-73
LG 16 TL
10- 2-70
6- 1-71
S-15-71
1?- 2-71
?- 2-72
7-11-7?
11- 1-72
2- 8-73
5- 7-73
1- 2-73
LG 17 «.»l
10- 3-70
10- 3-70
10- 6-70
6- 8-71
9-15-71
12- 2-71
2- 2-72.
3- 2-72
5- *-72
1- 1-72
It- 1-72
?- 8-73
5- 7-73
«- 2-73
LG Ifl P'U
6- 8-71
'J-15-71
1?- 2-71
E UP
302
1560
19*<)
2070
AMD P
*83
762
«8*
11 ?5
1550
17*9
1933
2060
2195
AMD P
789
*8?
761
883
112*
1551
1750
1932
2051
219I»
PONfl l»5
28.9
25.6
22.2
21.7
ROS ?5
-99.9
20.0
16.7
13.1
2*.*
19.*
16.7
16.7
20.0
ROS *7
18.9
-99.0
18.9
16.7
16.0
2*.*
16.7
13.3
20.0
20.6
L PONOS E 90
28*
286
287
*79
757
885
113?
-0
1*00
1611
17*7
193*
2062
219*
27.5
29.*
25.6
-99.0
25.0
21.1
23.0
23.3
23.9
26.7
22.2
22.2
22.2
25.6
L PONOS E19.
1.7ft
758
886
-99.9
26.7
22.8
22S 63E
*015 7.66
6973 7.62
583J 7.9H
6571 7.38
21S 63E
29H* 7.50
2739 7.35
2605 7.*7
2902 7.5*
27*9 7.77
7517 7.29
78*7 7.*7
283? 7.29
29*6 7.*1
21S 63E
19*5 7.26
3531 7.65
3398 7,*7
3338 7.38
3389 7.**
351.1 7.86
3095 6.90
3372 7.*2
375* 7.*1
3663 7.1*
21S 63E
5386 7.*7
65*3 7.62
7*13 7.16
30776 7.*0
3550* *.78
31850 6.76
3057U 7.18
2979* 6.88
29022 6.77
32*06 7.25
306*1 5.66
J0996 5.61
30788 8.11
37131 *.9fl
5 21S 63E
7581 7.*5
7**6 7.25
61
-------
in
pirn nci
HO TA YP
7- 7-7?
1- 2-7?
5- 4-7?
8- 1-7?
11- 1-77
7- 8-71
5- 7-71
8- 7-73
LG 19 PHI
10- 8-70
in- 9-70
'.-71-71
6- 8-71
9-15-71
1'- 2-71
7- 7-72
8- 1-7?
10-11-7?
?- 8-73
5- 7-73
1C 70 HMI
6- 8-71
9-15-71
17- 2-71
7- 2-7?
3- 2-7?
5- 4-72
8- 1-72
10-31-72
7- 8-73
5- 7-73
^TTFIIf? AND L1CATION
NI/Hn TE1P
1131 1C.O
-o 20. n
11.01 21.1
1619 31.. 4
171.8 74.1.
1935 18.9
2061 21.1
7707 27.8
L PONO E 70
296 23.6
297 23.3
460,. 70.0
480 -99.9
759 71.1
950 18.9
1127 23.1
1616 32.2
171.6 20.6
1<336 20.0
7065 73.3
L PONDS £ 20
481 -99.9
760 22.3
949 20.0
1125 20.0
1299 20.6
1402 21.1
1617 25.6
1745 -99.0
1937 18.9
2064 70.0
f, 71 L UPPER PTJNOS 40
9-30-70
6- 8-71
9-15-71
17- 7-71
7- 2-72
5- 2-72
8- 1-72
11- 2-72
?- 8-73
5- 7-73
8- 1-73
291) 25.6
476 -99.9
756 26.7
98* 21.1
1133 23.0
1437 23.3
-0 24.1.
1766 22.8
1938 22.2
2071 73.3
2199 24v4
COtin PH MC03 CL ^04
706ft 7.U2
6777 7.43
6669 7.70
7471. 7.68
7?81 7.76
6906 7.70
6964 5.57
7436 7.18
21S 63E
10861 7.70
7191 7.67
7605 7.39
7992 7.50
7679 7.01.
7267 7,74
7586 7.49
80?6 7.88
7711. 7.88
7704 7.95
7662 7.42
21S 63E
U584 7.65
11160 7.65
10282 7.41.
11089 7.1.1
10833 7.66
10629 7.12
11588 7.51
11166 7.93
11446 ,8.00
12413 7.41.
21<5 63E
800ft 7.65
11715 8.1.5
8500 8.85
10530 8.20
10779 8.80
10046 8.76
11397 9.27
11277 8.96
10733 9.70
10583 9.17
117*0 8.72
79 1766
9U 1 78 3
88 1247
81 1733
86 174?
82 1203
77 1256
81 1259
31 21? 1
198 2817
113 1843
77 1115
69 1108
76 1110
81 1172
71 1092
57 1126
74 1087
75 1097
69 1094
31 212 2
» 244 23J9
254 2422
256 2359
252 7457
252 21.89
249 7489
192 2427
11.3 2463
137 2597
222 2899
31 331 1
72 161.4
45 2192
56 2307
30 2256
60 2184
53 2144
52 2182
-77 76D6
-77 7168
-77 2149
173 2178
7265
7779
771.0
?4 76
??9?
2309
773?
7203
2757
1827
3160
3208
3194
3078
3217
3377
3348
3335
3241
2670
2670
2612
7779
7775
7736
2773
7772
2829
2702
7817
3391
3366
326D
330?
3165
3385
3103
3386
3278
32 OD
P04
-.01.
-.04
.28
-.08
-. 04
-.0".
-.04
-9.99
-.10
-.10
-.10
-.10
-.10
-.10
-.04
-.08
-.10
.12
-.04
-.10
-, n
-.10
-.04
-.04
-.fl4
-.04
-.10
-.10
-.04
-.10
-.10
-.10
-.10
-. 04
-,04
-.414
-.04
-,4)4
-.04
-J). 9*3
NO 3
145.0
150.0
154.0
138.1
132.0
126.0
142.0
123.1)
14.0
3.8
.1
-.1
.3
.3
1.7
1.0
.3
.3
.3
16. r
11.4
11.0
6.2
4.9
5.6
.7
12.0
3.3
2.6
2,1
50.0
79.0
83.0
72.0
56. t)
47.0
39.0
56.0
44.0
31.0
NA
699
703
750
745
737
708
692
696
1942
837
708
764
743
767
741
744
728
773
753
1560
1810
1830
1787
1837
1643
1832
1792
1890
1935
1062
1440
1275
1440
1358
1390
1360
1310
1314
12^1
1250
K
5
i*
4
I,
5
7
6
48
48
62
170
177
168
159
202
190
176
168
201
46
49
52
52
57
55
51
84
108
60
136
342
297
208
293
278
237
751
746
221
307
OH
673
671
700
649
664
639
664
710
658
570
593
573
558
557
555
549
567
554
549
588
592
585
610
580
636
577
515
590
666
674
594
619
596
606
605
587
598
557
576
554
MC
248
249
246
248
245
244
252
242
326
360
422
420
415
418
409
421
419
413
420
269
284
259
264
281
276
267
278
280
ZV)
370
460
493
490
461
423
474
481
494
4-62
452
NH4
-.1
-.1
-.1
.1
.1
.1
.1
.1
.0
.0
.0
.0
.0
1.6
1.6
1.6
.3
.2
..4
.0
.0
1.7
.1
.1
.1
.1
.3
.2
.2
.0
.0
.0
9.9
7.3
7.3
9.5
10.6
ID. 2
11.0
45.8
F 1
.6
.6
.8
.8
.8
.6
-99.0
-10.0
.9
.8
,(,
.4
.4
.4
.4
.4
-99.0
-99.0
-99.0
.9
.9
.9
.9
.9
.9
.8
-99.0
-99.0
-99.0
.5
.5
.5
.5
.5
.3
.3
.3
.4
-99.0
-U). 8
1S-SUH
5341
5386
5386
5360
5277
5282
5321
8660
5559
6206
6284
6226
6143
6255
6438
6362
6378
6293
7610
7965
7836
8030
8149
7964
8023
7987
8364
8673
6741
8492
8464
8358
8313
8095
8308
8419
8232
79H2
-S3B82
LC 22 L UPPER PONH5 2? 27S 63E 31 331 2
5- H-71 477 -99.fl
-------
POINT IOFNTIFTEP BNO LOCBTION
MO 14 YR NUMB TFMP CONn PH
HC03
CL
SO*
PO* N03
NA
ca
NH*
F OS-SUM
Ul
LG ?3 RMI
fi- 8-71
1-16-71
17- 2-71
tl- 2-7?
H UPPOND *5
*«•; -99. 0
768 ?2.5
985 20.6
1761. 22.8
LG 25 TIHFT HITCH 2*
9-16-71
12- 2-71
?- 3-7?
5- 2-7?
8- 1-7?
11- 1-7?
2- 8-73
5- 7-73
770 25.0
951 21.7
1136 20.0
1291 20.6
-0 30.0
1763 25.6
19<»1 IB. 9
2066 21.1
LG 26 TIME? DITCH 100
6- 8-71
•>-16-71
1?- ?-71
?- 3-7?
3- 2-7?
5- 2-7?
8- 1-7?
11- 1-7?
2- 8-73
5- 7-73
LG ?7 UMI
10-16-70
6- 9-71
9-t*-71
12- "-71
?- 2-72
3- 2-72
5- li-7?
8- 1-7?
It- 1-7?
?- 8-73
5- 8-73
LG ?8 BMI
5- 9-71
1-l*-7t
12- 3-71
?- 2-7?
3- 2-7?
5- *-72
8- 1-7?
«t86 -99.9
769 23.1
95? 22.V8
1137 19.0
129? 23.9
11,31, 2*.*
1557 Zlt.it
1762 25.0
191,2 23.9
2067 26.7
L PONDS M 62
293 21t.l»
<»9& -99.9
753 -99.9
959 in. 9
1131) 20.0
1296 21.7
11,03 21.1
1613 22.8
1767 22.2
19<»5 21.7
2075 26.7
L PONDS W19.
1,95 -99.9
75l» 21.7
958 20.0
1135 17.8
1?95 18.3
lit Oh 18.9
1617
7816 11.35
8S?B 11.10
06 1.21 1
281 171.6
261. 1550
2?7 1578
155 ?0l»9
07 232 2
129 1***
52 863
108 1151
127 877
92 636
1*0 538
132 587
105 270
07 232 1
11. 2307
1.0 21.19
51. 2378
51 2*38
52 21.15
50 21.07
52 2*31
58 2367
23 2367
50 23"»7
36 211 1
-77 2062
150 2159
11.2 238*
156 2302
167 1911
165 1915
179 1713
183 1623
135 11.1.3
161 1>*2I.
186 1223
36 211 2
-77 2501
-77 2*13
-77 2*07
-77 2106
-77 19**
-77 18*9
-77 166*
87?
6?9
9*6
757
599
5*3
607
681
685
6*8
6*5
826
213
2*0
237
250
256
260
270
3
3
252
1333
1238
1330
1379
1329
133*
1292
1**2
1516
1*95
1365
931
131*
1277
1298
1275
1253
1*16
-.10
-.10
-.10
-.0*
-.10
-.10
-.0*
-.0*
-.0*
-.10
.10
-.0*
-.10
-.10
-.10
-.0*
-.0*
-.0*
-.0*
-.10
-.10
-.0*
28
- 10
- 10
- 10
- 0*
- 0*
- 0*
- 0*
- 10
- 10
- 0*
.62
.56
.*0
.58
.72
1.7?
-. 66
138.0
*8.0
76.0
122.0
186.0
**.o
110.0
72.0
9.2
15.6
17.0
1.9
.6
-.1
1.1
2.0
*.*
.5
.2
,2
.2
-.1
6.r
6.1
2.3
8.0
3*.0
.2
2.*
.9
.2
.3
-.1
3*.0
8.*
2.3
10.8
10.3
*.*
?.*
530
510
5*8
787
36*
3*0
386
3*5
3*3
328
393
3*9
539
537
529
530
521
510
521
506
5*2
505
2017
181*
1665
1683
1*35
1*65
1353
1325
1275
1271
1107
2355
2525
2*10
21*5
2083
2023
1915
25
22
22
30
**
28
2*
20
18
13
10
8
26
29
?6
26
27
26
26
27
36
2*
35
20
2*
26
2*
29
23
23
29
30
19
8
8
9
to
13
7
8
501
357
382
*75
328
1*5
2*0
19*
119
129
123
87
570
515
507
529
522
5*6
516
526
*62
*9*
83
221
321
38*
305
280
289
277
28*
253
2*2
11
1*
?*
-0
20
*
22
326
283
338
2**
305
176
237
193
139
110
9*
78
280
295
29*
291(
296
292
298
290
26*
265
-1000
*2
73
9*
81
80
73
81
80
83
67
1
-0
-0
-0
1
0
2
.0 1.*
.0 1.5
1.2 1.6
1.2 .8
.0 .5
*.2 .6
.1 1.0
.1 1.1
.1 1.1
.1 -99.0
.2 -99.0
.5 -99.0
.0 .3
.0 .3
1.2 .3
1.2 .*
1.2 .3
1.2 .3
1.2 .3
1.2 -99.0
1.2 -99.0
1.2 -99.0
.0 1.*
.0 2.0
.0 2.0
1.7 1.9
1.7 2.1
1.7 2.0
1.7 2.2
1.7 2.3
.0 -99.0
.* -99.0
.* -99.0
.0 .7
.0 .8
2.2 .9
.2 1.0
.2 1.0
.2 1.0
.2 1.0
*278
3530
*00*
*5*2
333*
2169
2809
2**6
1996
1851
193*
1671
3893
(,055
*001
*096
*068
*067
*089
37*9
3687
3913
5538
5576
5872
5956
5205
5189
*838
*867
*69*
*636
*116
58*1
628*
6133
5572
53*9
51*3
5031
-------
POINT IHENTIFIER ANO LOCATION
(Jl
MO TA YR NUMB TEMP
11- 1-72 1768 23.*
CONO PH
816* 10.98
Lfi 29 DUCK CK AT LVW1DO 21S 62E
*-?2-71 *51 -90.9
6-10-71 «t99 -99.9
9-l*-71 752 20.6
12- 3-71 961 17.8
2- 2-72 1099 10,8
7-11-72 15*9 21.1
11- 2-72 1770 18.9
5- 8-73 2077 21.7
LG TO DUCK CK AT LVH
6- 9-71 1.97 -99.0
9-l*-71 755 19. l»
12- 3-71 960 17.8
2- 2-7? 1098 17.0
7-31-7? 151.8 23.3
11- 3-7? 1769 18.9
2- 8-73 191.6 17.8
5- 8-7t 2fl76 25.6
8- 1-73 2203 22.2
LG 31 GIBSON RO 62
6- 8-71
-------
POINT IOENTJFIFR «NO LOCATION
HO OA YP
1- ?-7?
It- 2-7?
*- 8-73
5- 7-73
a- 1-73
UG 11. «K
f>-10-7t
9-14-7!
13- 3-71
?- 3-72
3- 2-7'
5- 4-7?
7-31-7?
11- 3-72
2- 9-73
5- 8-73
8- ?-73
LG 35 ORI
10-12-70
6-10-71
9-14-71
12- 3-7t
2- 3-72
3- 2-7?
7-31-72
11- 3-72
2- 9-73
5- 8-73
8- 2-73
NUM5 TEMP
150(1 30. n
1761 25.0
!<)<> 7.1,0
6341 7.79
56*5 7.53
5785 7.5<»
61,8? 7.58
6831 7.52
215 62E
1761 7.1,3
1663 7.65
15?5 7.81,
1475 6.80
1575 7.53
1569 7.77
1605 7,98
1561, 7.57
1511, 7.75
1571, 7.65
1867 7.57
21S 62E
6828 7.50
555". 7.28
8080 8.11
1,81,5 7.65
3959 7.52
3800 7.1,5
36«»7 7.47
1,013 7.82
3891, 7.71
4039 7.56
1.318 7.52
1,833 7.50
2tS 6?F
81,51 7.55
7fl7 7.98
HC03
100
238
120
11?
181,
15 1,1,1
268
268
265
265
272
291,
301
270
271
310
333
15 1,1,1
125
202
170
193
203
214
130
132
152
123
107
22 241
65
84
40
54
91
125
36
49
30
39
46
48
22 ?41
98
157
CU
470
2327
529
437
1674
1
427
388
378
367
436
489
456
372
488
481
481
2
267
46
45
44
45
49
50
46
46
51
62
1
856
708
981
688
614
603
597
592
612
623
656
683
1
980
8
S04 P04
314 -.04
1380 -.04
384 -.04
318 -.04
1041 -9.99
3087 -.10
3050 .14
2830 -.10
2874 -.04
3094 -.04
3329 -.04
3236 -.06
28T5 -.04
3075 -.04
3378 -.04
3327 -9.99
2741 -.10
704 -.10
657 .10
599 -.10
677 -.04
698 -.09
694 -.04
680 -.04
671 -.04
696 -.04
815 -9.99
2754 -.10
2278 -.10
3455 -.10
1999 -.10
1338 -.04
1327 .34
1274 -.04
1292 -.04
1213 -.04
1453 -.04
1500 -.04
1613 -9.99
760? -.10
2?0 -.04
M03
-.1
-.1
-.1
.3
-.1
53.1
51.0
41.0
32.0
42.0
35.0
28.0
22.0
36.0
35.0
50.0
18.0
.1
-.1
-.1
-.1
1.9
-.1
-.1
-.1
-.1
.3
58.0
1.3
.9
.4
2.7
3.1
5.6
-.1
-.1
-.1
-.1
-.1
1?0.0
.6
NA
308
1310
344
276
905
674
638
625
575
649
659
671
555
605
667
705
429
87
81
79
75
77
79
81
78
77
93
751
527
1117
447
265
264
271
268
259
313
326
364
1165
12
K
8
21
10
8
15
41
37
37
30
39
39
42
42
30
40
43
28
11
12
10
11
11
11
10
11
13
10
26
24
33
18
15
18
15
17
16
17
17
18
30
4
C«
71
4?3
91
77
283
446
432
399
388
417
471
443
464
419
445
424
475
146
126
117
137
142
119
119
126
120
139
488
471
455
420
317
336
288
767
265
281
292
318
552
72
HG
49
264
57
45
184
354
341
340
353
359
420
389
325
391
429
405
289
96
91
88
93
95
95
94
91
98
107
318
270
326
256
206
203
206
205
207
223
234
244
353
39
NH4
.1
.1
.1
.1
.1
.0
.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
.2
.1
.0
.0
.0
1.8
1.8
1.8
1.8
1.8
.1
.2
.2
.0
.0
.0
10.0
1.0
5.2
6.4
6.4
6.4
6.4
11.0
10.8
.0
.0
F
.8
2.0
.9
-99.0
-10.0
1.6
1.6
1.6
1.8
1.6
1.6
1.8
1.9
1.8
-99.0
-10.0
1.5
1.7
1.7
1.7
1.8
1.8
1.6
1.6
1.7
-99 . 0
-10.0
1.0
1.0
.9
1.0
.9
1.1
.9
.9
.9
1.0
-99.0
-10.0
1.0
.4
OS-SUM
1270
5844
1475
1218
4193
5215
5070
4784
4753
5174
5590
5417
4752
5101
5627
5599
4310
1191
1096
1035
1141
1182
1116
1098
1100
1115
1280
5284
4322
6388
3866
2805
2822
2681
2673
2594
2936
3059
3274
6861
434
-------
POINT inf»ITIFTER AND LOCATION
MO HA YR NL'MR TFHP COMO PH
HC03
CL
SOI.
POit
N03
NA
MG
F OS-SUH
Ul
00
LG 38 WHITNFY MESS 112
6-11-71 508 -99.0
1-1I.-71 75D 21.1
I?- .1-71 951. 20.6
2- 2-7? 101.1. 20.0
8- 2-7? 1589 ?8.3
11- 1-72 1759 21.7
?- 9-73 1950 15.6
5- <»-73 201.6 22.2
LR 39 HHITNF.V MESA <»0
ft-ll-71 507 -99.0
9-1I.-71 71(9 20.6
f- 3-71 987 19. 1.
2- 1-72 10<»5 20.0
8- 2-72 1538 25.0
11- 1-72 1758 20.0
?- 9-73 19^9 19. 1»
5- 1.-73 201.5 20.6
LG "(0 WHITNEY MES« 110
6-11-71 506 -99.0
9-1I.-71 71.2 21.7
1?- 3-71 955 20.6
2- 1-72 1097 21.0
8- 2-72 1608 22.2
11- 1-72 1757 -99. 0
Z- 9-73 19<«* 18.3
•5- 1.-73 201.1. 22.2
LG '.1 UPPFP UVH 67
6- 9-71 1.90 -99.0
9-27-71 788 -99.0
12- 3-71 989 18.9
3- 1-72 11M 18.9
7-31-72 151.1 21.1
11- 1-72 175«t 20.0
2-12-73 1961 20.0
5-
-------
P-OINT JUFNTIFTER AND LOCATION
U1
MO *>A YR
8~- 2-7r
tG 41 MO
6-tt-M
9-14-71-
12- 3-71
2- 1-7?
8- 1-72
8- 2-7-2
It- 2-72
2- 9-73
5- 4-73
LG 44 NO
6-11-71
9-14-71
12- 3-71
2- 1-72
8- 2-72
11- 2-7?
2- 8-73
a- 2-73
LG 45 CA1
6-H-71
0-14-71
1?- 3-71
?- 1-7?
8- 2-7-2
11- 3-72
?- 9-73
5- 4-73
8- 3-73
NirWfl TFMP
2216 22.2-
»A*E SP 56
505 -99»0
748 20.6
956 14.4
1151 20.0
2214 22.2
1610 22.2
1755 19.4
1952 20.0
2043 M.I
NAME SP 129
504 -99.0
747 21.7
957 19.4
1152 20.0
1609 21.7
1756 19. V
1951 19.4
2213 26.1
P«ELL f?ES 125
500 -99.0
740 ?Z.Z
992 20.6
1153 22.0
1611 23.3
1774 22.2
1953 19.4
2052 25.0
2223 22.2
LG 46 CAMPBELL RES 40
6-10-71
9-14-71
12- 3-71
?- 1-72
8- 2-7?
11- 3-7?
?- 9-73
5- 4-73
1- 3-73
501 -99.0
741 22.2
993 20.0
1154 21.0
161? ?2.8
1775 21.7
1954 21.1
2053 22.8
222? 23.3
LG 47 CHARLES BLVD 100
6- 8-71
9-13-71
t?- 3-71
?.- 1-7?
492 -99.0
738 21.7
963 20.6
1150 21.0
CONn HH-
1080 7.42-
21S 6?E
37«r9 7.?2
3703- 7.52
3219 6.85^
3316 7.19
3320 6.93
3511 7.73
3407 6.95
3221 6.93
3236 6.73
21S 62E
3643 7.25
3594 7.54
3338 7.70
3389 7.18
3471 7.72
3449 7.14
3302 7.30
3501 7.22
21S 62E
1074 7.2fl
8 33 6 .93
797 7.00
653 7.57
587 8.11
547 7.72
5?6 7.72
544 7.91
594 7.86
21S 62E
874 7.60
839 7.64
807 7.46
886 7.54
1074 7.85
959 7.34
1030 7.55
1196 7.76
1332 7.20
?9S 61F
4fi9 8.00
476 8.00
4 84 7 . ri
466 7.92
HCOT
?2»
29 43V
246
172
165
226
190
190
200
149
98
29 434
206
165
178
219
146
138
135
107
19 111
66
60
10*
136
122
126
133
128
140
19 111
186
166
180
171
165
129
162
177
193
36 444
191)
166
181
I'M
CL
60
1
364
ST3
355
362
366
365
372
365
373
2
381
392
382
378
386
388
384
376
1
12
13
31
16
15
9
11
10
16
2
23
21
28
26
38
36
42
69
68
1
9
10
11
7
SO 4 P04
26V-9.99
1460 -.10
1435 -.10
12&5 -.10
1262 -.04
1172 -9.99
1263 -,tt4
1229 -.04
1254 -.04
1205 -.04
1352 -.10
1295 -.10
1275 -.10
1307 -.04
1311 -.08
1283 -.04
13?5 -.04
1290 -9.99
504 -.10
558 -.10
292 -.10
219 -.04
157 -.04
153 -.04
150 -.04
156 -.04
161 -9.99
275 -.10
266 -.10
286 -.10
314 -.04
373 -.04
344 -.04
383 -.04
419 -.04
459 -9.99
88 -.10
7? -.10
1?1 -.10
«7 -.(14
W3
1.1
.2
-.1
.6
1.6
-»1
1.9
.2
-.1
-.1
.4
-.1
.4
1.7
.4
-.1
-.1
.2
-.1
-.1
— »1
-.1
.2
-.1
-.1
-.1
-.1
.6
.5
-.1
.7
.5
-.1
-.1
-.1
.6
.8
.8
-.1
.6
NA
43
245
233
2\30
235
235
231
222
229
217
272
239
228
231
227
222
229
235
20
20
25
17
16
15
17
19
17
18
22
23
24
34
33
37
40
44
12
10-
10
8
K
8
39
41
38
37
36
38
36
38
36
35
35
24
36
33
33
34
32
5
6
5
3
4
3
4
3
2
3
3
3
2
3
3
4
3
2
4
5
5
3
CA
46
420
383
303
315
236
287
290
275
256
347
319
3 re
318
286
268
271
246
139
81
75
64
39
37
34
36
40
96
73
90
90
109
78
97
117
131
37
?5
4?
34
HG
81
169
161
158
159
162
165
166
161
160
175
175
174
176
182
160
179
182
5B
46
45
37
34
35
35
36
43
44
46
49
49
61
58
59
64
69
34
32
36
33
MH4 F
,6 -1B.O
.0 1.6
.0 1.7
1.5 1.6
1.5 1.6
1.5 -10.0
1.5 1.6
1.5 1.7
.2 1.7
.0 -99.0
.0 1.2
'.0 1.1
1.5 1.2
1.5 1.2
1.5 1.1^
1.5 1.0
1.5 1.1
1.5 -10.0
. 0 ..*•
.0 .3
1.8 .4
1.8 .4
1.8 .4
1.8 .4
.1 .6
.1 -99.0
.1 -10.0
.0 .3
.0 .3
1.2 .3
1.2 .3
1.2 .5
1.2 .2
.1 .4
.1 -99.0
.1 -10.0
.0 .4
.0 .4
1.4 .4
1,4 .5
OS-SUH
615
?820
2712
2434
2486
2302
2447
2V17
2397
2295
266?
2537
2479
2558
2500
2444
2491
2415
763
554
526
425
329
315
317
323
348
551
514
570
592
701
616
701
799
868
278
236
316
268
-------
IDENTIFIES AND LOCATION
cn
O
MO n« VR
7-31-72
11- 1-7?
2-12-73
<;- *-7*
1- 2-73
NUMf* TEMP
15". 3 23.3
1751 20.6
1958 20.6
2050 flt.lt
2217 23.9
LC i|8 CHAIUSTON BLVD
6- 9-71
9-13-71
1?- 3-71
?.- 1-72
7-n-72
11- 1-7?
2-12-73
5- i(-73
«t- 2-73
LG *9 AK
6-11-71
9-15-71
Z- 2-72
5- 2-72
7-31-72
10-n-72
2- 8-73
5- 7-73
*91 -99.0
739 22.2
962 18.9
11*9 21.0
15*2 23.3
1752 20.6
1959 20.6
2051 22.2
2218 23.3
MO 20LC 35
509 -99.0
763 22.8
1128 20.0
H27 21.7
1556 28.9
171.2 21.1
1931 20.0
2057 23.3
LG 50 LV81 HELL MATS
5-17-71
6-11-71
LG •>! A*
3-10-71
1-10-71
*71 -99.0
528 21.0
LC COUP 30
371 -99.9
372 -99.9
CONO PH
707 7.98
622 7.56
532 7.80
*90 7.8
1.7
.8
2.2
NA
12
8
16
8
1*
t
11,8
168
135
131.
135
125
127
137
129
527
5 <»2
536
652
719
860
9<*0
101.2
608
932
1.03
1,38
K
*
it
it
-------
POTMT in^NTIFTES »Nn LOCATION
MO OA YR NUMH TFMP CONO PH HC03 CL
SO*
P0<» N03
NA
CA
MG
NHI»
OS-SUM
LG 55 «K NO 1IJLC 3?
9-?3-7i
2- 1-72
5- ?-7?
LG 56 NFV
3-«-70
5- *-70
- 1-72
7-11-72
0- 6-7?
11- S-72
1-16-73
2- 1-71
1*1*
1287
1307
1*58
15*7
1655
1791
1880
1915
-99.0
19.0
-99.0
21.1
22.2
21.1
18.9
18.9
18.9
6982
7255
7306
72 8*
7976
7975
307*
4088
6633
7.5*
7.51
7.73
7.58
7.70
7.55
8.20
7.98
8.23
22 22* 2
202
207
20*
198
209
199
199
195
186
7*8
696
7*8
716
808
79*
750
3*23
3510
358*
3558
35*8
3886
3953
.12
-.0*
.10
.28
.20
.16
.28
7*3 3756-99.00
526
3390
.16
101.0
8*.0
96.0
92.0
8*.0
87.0
86.0
83.0
73.0
1015
966
10*9
10€7
10*7
1207
1183
1196
781
59
79
69
62
*3
73
53
67
56
52*
53*
502
*96
5*8
507
**0
502
*50
310
333
319
332
329
335
3*2
3*1
350
.0 1.*
.0 1.6
.2 1.*
.2 1.3
.2 1.*
.2 1.3
'.2 -99.0
.2 1.*
.2 -99.0
6281
6306
6*71
6*22
6512
6989
6905
6786
5718
10 61 CITY LW TULE 706
6-l*-71 5*2 22.2
10- *-72 1691 22.2
19-5 60E 0* 3*1 1
*39 8.00 2*6 8 20 .12 1.8 8 2 M 26 .0 .2 228
*2* 7.79 2*7 6 21 -.00 2.2 9 1 *3 25 .0 .2 230
LG S2 CITY LV TULE 612 19S 60E 09 3*1 0
10- *-7? 1699 2?.2 *30 7.76 2*3 3
31 -.uJ 1.5
*6
25
.0
.2
23*
LG 63 T H GFE 325 2HS 61E 16 222 0
in- 5-72 1703 21.7 *?8 7.87 235 5
39 -.00
2.2
*3
25
.0
.2
2*0
LG f,
-------
POINT IDENTIFIER AND LOCATION
MO HA YO NUMH TEMP CON" PH HC03
CL SOI* P04 N03
NA
K CA MG NH«i F OS-SUM
LG fi6 NELLIS AFB 350
10- 5-7? 1710 20,0
20S 61E 03 1.1? 0
41? 7.76 231 5
33 -.00 1.3
1 44 23 .0 .2 229
LG F.7 *0«7 H L HEAD 665 205 61E 20 311
10- 5-72 1712 19.4 ' 519 7.79 234 13
72 -.00 3.0
10
1 55 32
.2 301
LG f,9 3001 H L HEAD 301 ?OS 61F 20 311 0
10- 5-7? 1713 20.0 652 7.72 -0 18 13
-------
POTNT IDFNTIFIER AND LOCATION
MO HA YR NUMfJ TEMP CONO PH HC03
CL S04 P04 N03 NA
K CA MG NH4 F OS-SUM
LG 79 5326 TOPAZ 21S 6tE 25 312 0
10-13-72 172B 20.0 11?0 7.71 161 96
307 -.00 2.7 106
l» 86 30 .0 .3
LG Id 7117 PARADISE 335 22S 61E 03 441 0
10-13-7? 172q 28.9 1?K9 7.39 196 73
1.55 -.00 2.7 1,3
10 148 51. .0 .7 881,
LG 11 7044 TOMIVASU 201 22S 61E 01 413 0
10-13-72 1730 25.F, 1346 7.41 207 104
437 -.00 2.7 57
15 171 61 .0 .8 950
LG 12 5321, SANDHILL 390 21S 62E 30 422 0
11-17-72 1731 23.3 891 7,45 212 18
358 -.00 2.4 24
6 106 53 .0 .3 672
LG 13 600H E CHAPL 200 21S 62E 03 312 '
10-20-72 1736 16.7 395 7.1,8 192 4
•,7 -.00 1.6 19
i» 32 18 .0 .3 222
LG 81. 6140 S PEARL 600 21S 62E 31 133
10-20-72 1737 16.7 8*7 7.83 116 19
377 -.00 .8 23
6 90 49
.3 621
a\
Co
LG 93 CASEY NO SANDHILL 21S 62E 30 2«»1
1-10-73 1887 22.2 10056 7.75 202 22
368 -.04 2.5 26
6 118
51
.0
.<(
693
LG «8 OILLIMGHAM 25
<»-ln-73 2026 20.0
5- 9-71 2080 23.3
9- 6-73 2255 23.3
21S 62E 08 1*33
2121 7.85 279 137
2030 7.1,3 281* 133
1822 8.00 257 120
785-99.00 1.5 112 6 177 126
767 -.B4 .4 114 7 179 122
689-99.00 .8 98 2 187 110
.1 .3 1482
.1 -99.0 11,62
5.3 -99.0 1339
LG 99 W W GOLF CRS 26 21S 62E 09 122
<»-18-73 2025 21.1 5302 7.57 1,89 M>2
5- 9-73 2081 25.6 5001 7.59 198 «r!6
9- 6-73 225* 21.1 1,716 8.09 371 *03
23«,5-99.00 I*.5 1,22 59 395 356
2235 -.04 95.0 lfl 7.46 127 799
4975-99.00 .7 154B
5100" -.04 12.4 1571
93 522
27 511
475
467
.4 1.4 8559
.4 -99.0 8550
IG112 STTROREK 20
4-18-73 202? ZO.O
T.- 9-73 ?087 ?4.4
'?1S 61E 02 213
5412 7.67 427 2BO
4412 7.58 20B 212
210'»-99.00 .1 447
2270 .16 .5 363
4? 440
26 333
372
317
.2 .4 4603
.2 -99.0 3624
-------
POINT IDENTIFIER AND LOCATION
MO f)fl VR NUMO TEMP
9- 7-73 2264 26.7
LG1H3 HOTOP tffHCLS 10
4-18-73 2021 -99.0
5- 9-73 2078 23.3
9- 6-73 2256 28.9
LG104 PFTSPSON 8
<»-l«-73 2029 16.7
5- 9-73 2086 21.7
9- 5-73 2260 27.8
9- 7-73 2263 26.1
LG1H5 JARRETT 36
i»-t8-73 2030 19.*
5- 9-73 2085 22.2
9- 6-73 2261 21.1
15106 ENGELSTAO it 6
5- 9-73 2083 24.4
9- 6-73 2253 22.8
LG107 HCSTRAV1K 31
i»-l8-73 2031 21.1
5- 9-73 2084 23.9
9- 6-73 2252 24.4
CONn PH
42C.1 7.99
21S 62E
3469 7.61.
3521 7.71.
3701. 8.11
21S 61E
7533 7.67
6678 7.i|6
59410 7.78
5361.0 7.85
21S 61E
1.877 7.69
1.560 7.37
1.716 7.83
22S 61E
3177 7.18
2700 7.94
21S 61E
2349 7.65
2246 7.«»1
2200 8.12
LG10B H OF I15MILO HY36 21S 61E
••-18-75 2028 21.7
5- 9-73 2090 22.2
9- 6-73 ?259 21.1
LG109 VV AND OKY 39
(.-17-73 2033 21.7
•5- 9-73 1520 ZU.it
9- 6-73 2?57 21.1
L6110 JOSEPHS 35
1- 2-71 1966 25.6
4-18-73 203? 21.1
5- 9-7^ 2088 25.6
9- 6-73 2258 23.9
ID- <>-72 -0 .0
3251 7.62
265.8 7.1,9
2307 7.95
21S 61E
281.5 7.77
2903 7.54
2861. 8.03
20S 61E
2706 7.67
2971. 7,66
292? 7.53
2763 7.93
0 .00
MC03
409
01 1.31.
173
179
215
13 223
300
306
CL
216
238
239
31.8
427
1.08
<*92 12890
1.76
23 1.12
2<>a
242
235
23 1.12
173
99
26 332
195
222
235
08 13d
193
190
209
05 323
263
263
258
33 342
2<>6
298
1.31.
378
378
9491.
292
282
294
203
175
106
100
107
129
il!2
113
189
187
190
158
181
172
173
0
S04 P04
2238-99.00
1625-99.00
1733 .04
1694-99.00
3973-99.00
3645 .04
31384-99.00
27516-99.00
26 17-99. 00
2662 .04
2690-99.00
1620 .04
1640-99.00
1022-99.00
1004 .04
1012-99.00
1733-99.00
1349 -.04
1102-99.08
1192-99.00
1237 -.04
1270-99.00
1110-99.00
1275-99.00
1210 -.04
1212-99.00
0 .00
NO 3
.4
4.4
8.0
5.5
.3
.8
175.0
198.0
.0
.6
.8
-.1
1.8
.2
.3
3.0
*T» tf
77.0
74.0
1.7
66.0
62.0
3.3
2.0
2.0
.3
.0
NA
382
141
122
237
942
778
13975
11950
329
299
347
111
109
167
152
173
87
58
76
191
187
203
161
178
171
182
0
K
35
23
23
49
169
123
4560
3865
22
14
32
12
9
9
10
9
9
8
8
12
12
8
20
24
22
30
0
CA
300
433
478
489
498
517
750
717
534
519
515
416
362
200
217
203'
444
361
336
191
219
210
117
171
196
204
0
HG
311
171
172
150
360
370
2602
2416
303
308
313
194
192
117
119
114
187
163
140
189
197
203
216
235
239
236
0
NH4 F
.2 -99.0
.2 .4
.2 -99.0
.5 -99.0
.2 .5
.2 -99.0
2.1 -99.0
2.1 -99.0
.1 .0
.1 -99.0
.1 -99.0
.0 -99.0
.0 -99.0
.1 .4
.1 -99.0
.1 -99.0
.4 .3
.4 -99.0
.4 -99.0
.8 .3
.8 -99.0
.8 -99.0
.0 .4
.4 .4
.4 -99.0
.3 -99.0
.0 .0
OS-SIW
3684
2721
2863
3079
6518
5993
66580
56392
4216
4203
4307
2641
2538
1717
1711
1737
2718
2221
1952
2096
2235
2273
1907
2213
2226
2223
0
-------
POIMT tnr«ITIFIEI? AND LOCATION
HO Oft YP, NUMB TEHP OOMH PH
HC03
CL
S04 P04
N03
NA
K CA MG NH<» f OS-SUM
H
C^
Ul
L.G112 CUPT
6- 8-73
10- 4-72
LG113 700(1
6- 8-73
10- 4-72
LG114 RNCH
6- 8-73
in- 5-72
MANN02 312
2147
1701
24.4
.0
613
n
GILCREAS 560
2135
1702
25.6
.0
416
n
SUP CLUB 605
2134
1704
LG115 LA PAZ TR
6- 8-73
10- 5-72
LG116 2342
6- 8-73
10- 5-72
LG117 2934
6- 8-73
10- 5-72
2138
1705
26.7
.0
PK 200
25.6
.0
433
0
398
0
N PECOS 209
2137
-8
LVSN
2139
1709
LG118 NELLIS AFB
6- 8-73
10- 5-7?
LG119 4434
6-12-73
10- 6-72
LG170 DAY
6-12-73
10-11-77
LG121 CLU1
f>- 8-73
10-11-7?
'LG122 716
6- 8-73
10-12-7?
500
1711
CRAIG
2145
1714
OPEAM
2146
1716
25.9
.0
300
26.7
.0
1 800
26.7
.0
RO 900
25.0
.0
RANCH
99.0
.0
398
0
549
0
519
0
384
0
1016
0
95 295
2133
1719
SHAnoH
213?
1723
28.9
.0
L 226
26.7
.n
4^4
0
4 3d
n
20S
8
19S
7
19S
8
205
7
205!
7
20S
7
205
7
20S
7
22S
7
20S
T
?QS
7
62E
.03
.00
60E
.74
.00
60E
.04
.00
62E
.83
.00
62E
.82
.00
61E
.90
.00
61E
.89
.00
61E
.68
,00
61E
.46
.00
61E
.80
.00
61E
.83
.00
24 111
262
262
23 223
239
239
27 112
239
239
19 312
200
200
19 222
249
249
13 142
251
251
19 441
243
243
04 144
193
193
12 22?
205
205
19 442
235
235
33 331
225
225
1
20
0
6
0
4
0
7
0
8
0
18
0
n
0
4
0
26
0
4
0
4
0
74-99.00
0 .00
20-99,00
0 .00
26-99.00
0 .00
37-99,00
0 .00
48-99.00
0 .00
69-99,00
0 .00
29-99.00
0 iOB
38-99.00
9 .00
365-99.00
0 .00
36-99.00
0 .00
46-99,00
0 .00
11.
*
2.
•
5
0
9
0
Z.4
*
1.
0
8
,0
1.
ft
1.
•
3.
•
•
»
3.
•
™ »
•
2.
*
1
0
9
0
3
0
6
0
2
0
0
0
0
0
17
0
10
0
8
0
15
0
27
0
22
0
18
0
18
0
23
0
7
0
7
0
2
0
1
0
1
0
2
0
4
0
2
0
3
0
3
0
6
0
2
0
2
0
51
0
39
0
41
0
24
0
25
0
36
0
35
0
32
0
120
0
4fl
0
44
0
36
0
24
0
24
0
29
0
34
0
3
0
25
0
19
0
51
0
22
0
26
0
.2
.0
.0
.0
.0
.0
.0
.0
,0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.1
.0
•* ,
.0
.2
.0
.2
.0
.6
.0
.9
.0
.7
.0
.6
.0
.6
.0
.5
.0
.2
.0
.3
.0
J42
0
221
0
224
0
214
0
271
0
275
0
241
0
210
0
696
0
234
0
243
0
-------
POINT inFNTIFTEP AND LOCATION
MO OA YR NUMB TEMP -CQNO
LG123 1201 FREMONT <»60 20S
6- 8-73 211.lt 25.6 1.13 7
10-19-7? 1732 .0 0
LGt?i. MTCHFLAS 1 650 21S
K-lt-73 21fc3 26.1 529 7
10-1^-72 1733 .0 0
LG125 MTCHELAS 2 810
6-11-73 2H.2 25.6
10-20-72 1731. .0
LG126 NLV «IR TERM 500
6-18-73 21UO 26.7
10-20-72 1735 .0
LG127 LORNZI PK 600
6-18-73 21M 26.7
LG128 AK LOS FARM 30
I.-11-73 ?026 17.8
LG129 LV EXPHY NO VV 10
2- 5-73 1921. 19.1.
LG132 MELOOY NO CYP 5
7-18-7^ 21U9 -99.0
LG135 2100 BLEOSOE 215
11-22-72 1823 -99.0
LG136 3102 ALOHA 100
11-22-72 1821 -99.0
LGH7 3208 S. TOPAZ 375
11-22-72 1821 -99.0
LG13H ?"*32 Mtl. PKHY 6
•>- 6-73 1925 13.3
21S
1.69 7
0
20S
1.20 7
0
20S
1.1.3 7
21S
5551 8
20S
1170 7
20S
1.569 7
20S
555 8
21 S
290fc 8
21S
510 8
21S
3806 7
PH HC03 CL SO". P0«. N03 NA K CA *G
61E 35 322
.60 201. 5 1.6-99.00 1.9 9 3 1.2 23
.00 20<« 0 0 .00 .00000
61E 01. 1.13
.71 220 8 90-99.00 2.1. 10 3 51. 29
.00 220 0 0 .00 .00000
61E
• 91
.00
61E
.86
.00
61E
.82
62E
.05
61E
.87
60E
.27
62E
.1,2
62E
.22
61E
.52
61E
.85
01. 1.13
222 6 61-99.00 2.1 -9 2 1.9 25
222 0 0 .00 .00000
18 233
231. « 29-99.00 2.0 7 1 fc7 22
231. 0 0 .00 .00000
18 233
233 5 1.0-99.00 2.5 7 2 1.9 23
15 332
336 558 1999 8.83 91.0 716 101. 326 159
30 1.1.2
239 67 31i.-99.00 9.3 79 6 88 53
19 Ml
582 226 2228-99.00 ^.* 297 60 31.1. 356
21 31,1
387 12 52-99.00 -.0 26 12 29 1.9
08 431
187 281 118i.-99.00 .3 95 12 2U8 215
12 31.2
216 17 7l.-99.00 2.1. 11 2 1.9 30
10 11.1,
162 182 1976-99.00 1.0.0 225 55 316 276
NHl. F OS-SUM
.0 .3 230
.0 .0 0
.0 .3 301.
.0 .0 0
.0 .2 261.
.0 .0 0
.0 .2 227
.0 .0 0
.0 .2 21.3
.0 .9 1.128
.0 .3 733
.1 .8 3799
.0 .8 332
.0 .6 2128
.0 .3 292
.0 .3 3150
-------
POINT IOFNT1FTE1* ANt) LOCATION
MO Oft YR NUMB TEMP CONO PH HG03 CL
SOI, P01, -N03
NA
K CA
KG NH"t
F OS-SUM
LG139 1850 SYCAHORE 17 20S 61E 19 1,22
7-18-73 2150 -99.0 198? f.65 383 13B
519-99-nO 52.0
25 92
107
.3 1276
62M HITTIG 208 19s &OE 23 112
7-18-7^ 21«,« -99.0 1556 7.77 268 69
230-99.00 370.0
26
7 159
05 .0
.2 1078
LG150 1 MI E LK tIEAO 1R 22S BSE flit 3<»1 1
R-15-75 -0 -.0 1177 7.9B 256 119
288
.10
5.5
169
12
16
.0
771,
1G151 BESIDE LG007
8-15-75 -fl -.0
?1S 63E 28 131 3
6610 7.1,3 23* 1135
1995
.67
-.5
671
91 553
232
.0
-.0
1,793
LG152 1/2 MI H HENO STP 21S 62E 35 1,11 1
8-15-75 -0 -.0 3201 R.01 226 535
710 5.6B
.3
<«OS
20 193
69
.0
-.0
2053
LG153 .5 MI S SUNSET RO 225? 62E 03 333 1
1-15-75 -0 -.0 1198 8,32 2«t2 58
296
.61
.3
22
12
22
-.0
538
LW 1 LRS
6- 6-70
7- 7-70
8- 6-70
9-11-70
9-11-70
17-15-70
1-19-71
2-18-71
28.0
30.0
30.0
25.0
22.8
20.5
16.9
25.6
23.5
26.7
-99.9
3D.O
27.8
18.9
-99.0
1136
2010
10 ill
1530
16U6
211,6
2070
1707
1753
1761,
2025
2086
1813
1891
1761,
1898
1791
2230
2071,
2198
1876
1810
1655
1625
6.90
7.75
7.86
7.12
7.07
7.51
7.51,
7.31*
7.20
7.35
7.1,5
7.30
7.23
7.29
7.13
7.72
7.15
7.28
7.18
6.80
7.07
7.T?5
7.29
7.32
?3 231 1
21, d
1,51
180
191
181
208
163
287
296
293
275
276
291
298
265
261
282
265
225
305
131
296
251,
21,1
116
230
111,
188
191,
281,
280
2"i3
232
305
276
275
261
260
21,5
256
293
262
256
268
261,
252
188
169
177
316
160
279
327
601
396
2«3
262
317
3Bit
331
2.1»
21.0
25.9
32.0
21.0
20.0
19.0
18.0
11,. 0
21,. 0
.1
28.0
17.0
23.0
.9
1.0
.8
.9
.9
1.0
.9
1.0
.9
.8
.5
.7
.7
1.1
.9
.3
1.2
1.0
1.3
1.5
.5
1.7
.1,
I.I,
728
1191,
61,6
952
1037
1612
1185
1075
101,1
1186
1233
1160
101,6
101,9
1105
1160
1120
11,60
131,2
1385
1002
1101
999
950
-------
POINT rflENTIFIER AND LOCATION
MO TA YR NUHB TEMP CONO PH HC03
CL
P04
NOJ
CA
MG NH4
F OS-SUM
cn
oo
UM 2 LAS
6- 6-70
7- 7-70
8- b-70
1-11-70
9-11-70
17-15-70
1-19-71
1-11-71
'4-22-71
6-11-71
7-?6-71
B-TO-71
10- 1-71
11-10-71
1?- 1-71
1- 3-72
»- 1-72
3- 2-72
5- 4-72
i<6
521
650
725
601
B41
896
1034
1169
1257
1377
11.1.9
2326
1622
1691.
2272
2282
2298
2213
2326
2332
2339
2352
2357
2365
237?
2375
2383
2387
2397
21.03
2M3
21.25
21.31
2M7
21.38
21.1.7
241, *
21.55
2461
21.61.
21.67
71.72
26.9
28.6
30.3
28.3
28.3
-99.9
20.6
19.0
23.9
28.0
30.0
30.0
21t.lt
22.2
20.5
16.9
18.0
18.3
22.5
25.0
-99.9
30.0
26.7
26.7
-99.0
-99.0
13.3
20.0
19.1.
26.1
28.3
26.1
30.0
29.1.
26.7
23.3
18.9
17.8
21.1
21.1
26.7
27.8
-99. 3
27.8
23.9
20.5
21.1
20.0
21.0
17.0
25.0
f.25
1718
1302
161.8
1672
2151.
2120
1737
1768
221.3
19B5
2597
2003
2f.3
1781.
1755
2213
2358
2657
7.051.
2326
2247
2131.
2050
2599
1819
1681.
2387
191.9
2275
1871
1815
2139
191.9
1921
1972
1*B3
2168
2215
2<»5B
2«>42
2086
2026
171.2
1935
2109
2100
2109
ign
1992
2144
6.85
6.85
7.83
7.22
7.35
7.55
7.1.5
7.50
7.27
7.32
7.20
7,1.5
7.1.2
7.26
7.13
7.33
7.19
7.19
7.37
7.20
6.78
7.05
7.25
8.11
8.26
7.72
7.68
7,27
7. (11
7.01
7.27
7.87
7.06
6.99
6.86
6.61.
7.1.1
7.39
6.76
6.80
5.80
6.30
6.15
6.72
6.1.3
6.90
6.1.0
6.60
7.31.
7.60
6.89
23 1.21. 1
220
192
183
190
180
196
159
321
289
291
281
270
269
291
269
275
265
291.
298
238
288
11.1.
296
151
113
108
112
119
176
?60
162
180
161*
262
156
217
307
21«i
207
235
150
1*2
149
176
143
107
100
155
95
137
111
1«.9
197
151
193
164
261.
279
161.
21.2
326
266
281
278
28<»
21 R
218
292
276
299
21.1
303
261.
283
279
249"
312
297
3U9
221.
307
21.3
202
302
277
256
261
17«»
302
281
345
322
302
290
206
26
-------
POINT nENTIFTEP AND LOCATION
MO OA YP NUMB TEMP COMn PH HC03
CL
S04 P04
N03
NA
CA
MG NH4
F OS-SUH
CTi
l» X LA>>
?.-28-7o
^-.11-70
5- 5-70
6- 5-70
7- 7-70
8- 6-7fl
9-10-70
9-10-70
12-15-70
1-19-71
2-17-71
3-11-71
^-TO-71
1-30-71
4-22-71
6-11-71
7- 7-71
7- 7-71
7- 7-71
7-26-71
8-30-71
10- 1-71
11-10-71
12- 1-71
1- 3-72
2- 1-72
3- 2-72
4- 5-72
5- 4-7?
6- 1-72
7-10-72
8- 6-7?
9- 6-72
10- 1-72
11- 6-7?
1?- 4-72
I- 4-73
1-31-73
3-
-------
POINT inn
nr> HA yp
6- 5-74
7- 2-74
8- 2-74
9- 4-74
10- 3-74
11- 6-74
1'- 4-74
2- 6-75
3- 7-75
4- 3-75
6- 3-75
7- 1-75
8- 5-75
9- 4-75
10- 7-75
11- 6-75
12- 3-75
12-30-75
2- 3-76
3- 4-76
4- 1-76
LH 4 LAS
6- 6-70
7- 8-70
8- 7-70
9-10-70
9-10-70
12-15-70
1-19-71
'-18-71
4-22-71
6-11-71
r- 7-71
7- 7-71
7- 7-71
7-23-71
8-30-71
10- 1-71
11-10-71
1'- 1-71
1- 3-72
2- 1-7?
3- 3-72
5- 4-7?
*>- 1-72
r— 10-7?
8- 6-7?
10- 1-7?
LW 5 L*S
5-21-70
6- 6-70
mFIER AND
NUMB TEMP
2353 20.0
2359 20.0
2363 25.0
2370 23.3
?376 20.0
2382 13.3
2338 D.I
2398 10.0
2404 12.8
2411 13.3
2426 19.7
2432 20.6
2435 -99.0
2440 22.2
2445 -99.0
2449 15.5
2453 15.0
2459 14.4
2463 14.0
2468 15.0
2473 22.0
VEGAS MASH
88 21.0
121 23.3
152 26.4
166 21.7
167 21.7
307 -99.9
336 9.4
381 13.3
441 15.0
514 20.0
621 -99.9
624 -99.9
627 -99.9
634 23.9
706 23.3
797 15.0
824 10.0
928 11.0
1011 8.1
1125 4.0
1252 10.0
1374 16.5
1442 22.?
1528 25.5
1620 25.0
1691 21-. 7
WEGAS HASH
95 17-.8
90 22.2
LOCATION
00 Ml
2578
3013
2954
2513
2922
2679
7384
2938
2839
2788
2543
2645
2532
2684
2927
2876
2588
2396
2541
2866
28P6
PH
7.66
8.13
6.98
7.65
7.55
7.35
7.38
7.13
6.90
7.03
6.60
6.50
6.87
6.81
7.00
7.70
7.30
6.70
7.48
7.58
7.05
4 21S 63E
4925
4577
3575
4612
5608
4046
4344
3500
3471
5160
6688
6463
6297
5514
6467
4184
4676
4054
3745
4003
4180
4460
4066
4375
4184
3752
7.80
7.75
8.10
7.70
7.83
7.l>5
7.56
7.50
7.91
7.75
7.85
7.90
8.00
7.30
7.75
7.78
7.66
7.45
7.93
7.45
7.78
7,74
7.47
7.78
7.73
7.65
5 215 63£
5196
5373
7.75
7.75
HC03
25?
25?
?57
266
25?
230
281
178
215
177
229
229
263
231
221
189
168
159
160
17?
183
29 324
275
302
272
266
362
217
228
229
257
280
253
260
254
271
250
255
214
203
225
206
233
242
243
256
265
?53
29 331
-241
235
CL
312
384
390
325
420
355
329
38?
378
285
314
331
312
350
375
385
344
329
362
385
389
1
1250
1025
762
1090
1015
663
700
572
520
816
1234
1152
1123
1042
1079
684
730
639
582
574
655
757
621
670
644)
571
1
1237
1300
S04 P04
697 21.00
814 16.80
748 20.20
658 21.50
688 29.80
656 18.30
580 22.00
764 21.35
762 22.00
964 13.50
596 26.10
626 26.10
627-99.00
677-99.00
734-99.00
739 20.00
668 25.60
624 24.00
668 20.50
808 14.38
798 17.45
1482 15.60
1135 19.00
1049 8.50
1085 12.62
1326 13.30
1226 16.80
1149 19.10
946 21.50
914 19.50
1264 17.40
1701 10.50
1670 11.20
1673 11.10
1379 15.40
1469 11.10
1076 15.30
1141 16.00
989 17.20
975 18.50
10-8* 18.60
1270 17.20
1262 18-00
1124 24.00
1185 16.70
1112 16.50
1058 17. 21)
1635 13/90
1584 11.10
Nf>3
8.7
9.4
3.0
5.3
8.0
17.0
26.0
24.3
22.0
21.0
2.9
2.5
53.0
52.8
6.0
8.3
10.5
4.5
3.5
14.4
13.1
28.8
21.0
16.6
28.4
26.1
47.6
44.4
34.2
29.6
25.2
39.0
25.0
28.6
36.4
36.4
32.0
53. »
49.0
46. fl
50.0
29.0
20.0
17.3
19.0
22.0
34.0
70.9
62.5
NA
298
345
342
272
339
316
268
328
320
282
267
281
270
297
331
322
280
275
319
300
334
854
690
500
750
700
508
514
468
423
497
700
720
691
598
618
496
501
431
415
428
516
51fl
464
*85
464
430
720
7°0
K
19
23
26
18
40
23
29
27
24
29
19
19
19
19
22
21
19
19
21
21
20
44
44
42
43
44
37
36
33
25
38
59
49
49
57
60
38
43
39
33
35
37
38
45
36
36
36
34
33
CA
tfVl
204
183
162
174
153
187
174
167
201
153
161
167
178
185
183
168
162
161
183
181
450
310
226
380
350
292
324
256
237
345
495
463
479
399
438
288
316
284
256
272
305
328
272
295
299
272
5lf
41?
MG
74
86
84
73
81
75
76
80
84
95
69
72
72
77
75
79
73
69
75
84
80
172
156
121
140
142
129
124
106
105
146
200
177
179
184
188
126
139
126
112
123
143
143
136
130
125
117
202
200
NH4
7.4
7.4
7.4
7.4
7.4
7.4
7.4
7.4
7.4
7.4
7.4
7.4
7.4
7.4
7.4
7.4
7.4
7.4
7.4
7.4
7.4
.0
.0
.0
.0
.0
.0
.4
2.3
.1
5.7
.5
.6
.5
.5
.3
1.4
1.3
3.0
3.2
2.6
.2
.1
3.6
.1
.3
.1
.0
-JO
F
-.0
-.0
-.0
-.0
-.0
-.0
-.0
-.0
-.0
-.0
-.0
-.0
-.0
-.0
-.0
-.0
-.0
-.0
-.0
-.0
-.0
1.5
1.4
1.2
1.3
1.5
1.2
1.2
1.4
1.3
1.3
1.3
1.4
1.4
1.1
1.1
1.2
1.1
1.0
1.1
1.1
1.2
1.2
1.1
1.3
1.2
*-*
1.1
1.2
OS-SUM
1722
2014
1930
1673
1911
1734
1662
1895
1892
1985
1568
1639
1657
1772
1844
1858
1678
1592
1716
1902
1930
4433
3550
2860
3661
3747
3027
3024
2553
2401
3293
4565
4397
4360
3846
4024
2883
3046
2678
2553
2693
3089
3197
2827
2964
2437
2668
4548
45 ID
-------
POINT inn
MO OA YR
7- S-70
8- 7-70
17-15-70
1-19-71
7-18-71
k-72-71
6-11-71
7-33-71
9-10-71
10- 1-71
11-10-71
13- 1-71
1- 3-73
Z- 1-72
3- 3-7?
K- 5-73
5- K-73
*>- 1-73
7-10-72
8- 6-73
10- 1-73
NTIFIEP. AND LOCATION
NUMR
13?
151.
308
337
383
1.37
513
633
705
796
831
936
1009
1159
131.9
1338
1373
11(1.1
1525
1598
1690
TFMP
23.1*
37.8
-99.9
10.0
16.7
17.8
21.0
25.6
2lt.lt
17.8
11.1
13.0
8.1
5.0
11.1
30.0
17.0
33.3
37.5
26.1
31.7
CONH
KR79
3953
1.609
1.863
1,1,95
1.701
6370
5961.
7093
5181
511.8
1.561
1.310
KK77
1.780
1.197
1.898
1.536
5088
5337
1.702
PH 1
7. HO
'.00
7.63
7.60
7.56
7.85
7.75
7.60
7.92
7.87
7.65
7.1.5
7.1.9
7.55
7.81
7.63
7.75
7.50
7.87
7.78
7.5l(
•IC03
330
356
315
321.
33K
338
31.5
335
311.
333
300
196
198
198
318
330
337
231.
31(1
31.3
338
CL
1175
881.
800
833
802
823
1150
1001.
1237
985
911
761.
738
691
876
739
885
781
870
919
839
50 1(
1360
1078
1367
1315
121(3
1293
11(30
11.60
151.3
1366
1281
1078
1105
1166
1382
1179
1335
1226
1311
1290
1191.
POI»
11.50
7.1.0
10.70
11.. 50
li(.l(0
11.30
12.1(0
11.70
7.00
11.80
11.. 60
IK. 80
IK. 90
15.10
IK. 00
15.80
15. KO
19.70
11.80
12.50
IK. 10
N03
KK.3
73.5
70.8
6K.O
66.5
61.0
5K.3
5K.5
56.8
50.0
53.0
53.0
50.0
55.0
3K.O
38.0
31.0
25.0
30.5
36.0
K1.5
NA
700
K95
576
566
50K
500
K99
591
617
5K5
538
K35
KK8
K55
537
KK9
5K5
517
539
555
528
K
63
60
5<»
K7
55
59
50
55
61
53
K9
K5
K8
K3
50
KK
K6
53
K8
52
51
C«
376
3KO
276
389
389
390
501
K91
515
K16
373
333
309
330
365
326
357
331
368
386
363
MG
183
156
155
153
150
169
•307
311.
319
17K
170
1K1
1K1
IKK
168
1KB
162
156
150
157
1K7
NHK
.0
.0
.0
.K
1.5
1.5
K. 1
.K
.1
1.6
1.2
2.5
2.2
1.7
.3
.3
.1
3.0
.1
.2
.1
r
1.3
1.1
1.1
1.1
1.2
1.0
1.1
1.1
1.0
1.1
1.0
.9
1.1
1.0
1.1
1.1
1.1
1.1
1.3
1.1
1.1
OS-SUM
3921
3330
3K16
3K83
3336
3K3K
K039
3998
K363
3613
3K89
3962
29K5
2990
353K
30K3
3K9K
3338
3KK8
3528
3395
LH 6 L»S
I.- 3-70
5- 5-70
6- 6-70
7- 8-70
8- 7-70
9-10-70
9-10-70
17-15-70
1-19-71
i»-?3-71
6-11-71
7-33-71
'-30-71
10- 1-71
1 2- 1-71
1- 3-73
?- 1-7?
7-10-73
17- it-7?
1- 1.-73
LW 7 LAS
3-?8-70
3-31-70
5- 5-70
ft- 6-70
7- 8-70
8- 7-71
9-10-70
9-10-70
VEGAS
30
53
93
131.
156
160
161
309
338
I|ii8
511
631
703
795
937
1006
1156
1533
1836
1BI.6
VFGAS
6
39
53
93
135
157
15«
159
HASH
15.0
18.9
31.6
23.3
36. <*
30.3
30,3
-99.9
9.1.
15.6
30.0
33.8
33.3
16.7
13.0
6.9
5.0
33.0
10.6
-99.0
HASH
-99.9
16.0
17.8
3?.?
33.9
35. f,
31.1
31.1
6
571.3
607U
5196
5153
1.398
1.567
581.3
1.953
511.6
51.73
6071
6035
7301
6397
lt761t
1.535
It7<- 1.
5791
1.1.11
1. 1.80
7
3903
51.76
6033
5078
5111
1.190
1.355
5ft"9
31S 63E
7.69
7.90
7.85
7.95
8.30
7.81.
7.98
7.88
7.81
8.03
7.90
7.83
8.05
7.71.
7.73
7.80
7.83
7.90
7.70
7.1.6
31S 63E
7.81.
7.90
7.95
8.00
8.00
8.19
7.80
7.86
38 113
331.
335
363
373
363
361.
361
331.
236
31.9
363
365
31.7
31.1.
311.
305
308
365
309
199
11. 1.11
117
337
250
371
391.
379
361.
365
1
11.85
1380
1130
1250
1038
1101
96 !»
885
853
951,
1000
131".
1310
1186
803
708
759
991.
783
71.9
1
995
1 M.5
1198
1130
1160
1001
1038
1103
1053
11.53
1686
1388
111.8
1371
11.88
1513
1385
15«>8
1491
1615
1693
1791.
1339
1213
1339
1611.
1331.
1178
1363
1303
1353
179?
1530
1377
1211.
151 n
13.20
9.95
11.70
11.80
8.23
7.13
11.10
10.90
13.50
8.90
10.80
10.20
6.60
3.80
12.80
11.. 20
It.. 1.0
9.00
13.60
16.20
13.87
13.20
9.70
7.50
10.50
5.10
9.89
10.30
51.. 5
26.8
1(8.7
1.6.5
57.6
57.6
51.. 5
72.3
61..0
58.0
1(7. »
I.I..O
51.1.
63.0
63.0
Stt.O
61.0
27.0
53.0
62.0
1.1.0
53.6
1.5.3
37.7
I.I..3
66. <«
57.6
1.6.7
610
696
730
700
515
61.3
633
557
578
561.
1(96
619
61(7
655
1.67
1.68
(.90
613
501.
1(79
650
616
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696
700
575
51.0
608
51
60
31.
71.
76
59
61
56
1.7
67
53
59
73
81
53
51
1.8
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1.3
1(3
1(8
50
58
31
67
66
55
61
1(75
510
516
1(36
1(05
1(30
1.33
397
1.38
1.73
491.
503
533
51.3
370
31.1
369
1.50
338
323
373
1.65
1.90
516
1.11.
1.55
-------
CO
"HINT inF
Mfl DA YR
1'-15-70
1-19-71
7-18-71
ft-72-71
6-11-71
7-23-71
8-30-71
in- 1-71
11-10-71
17- 1-71
1- 3-72
1-31-7?
?- 1-72
1- 3-7?
ft- 5-7?
5- 5-72
6- 1-77
7-10-7?
9- 5-72
9- 6-72
10- 1-7?
11- 6-7?
12- ft-72
1- ft-73
1-31-73
3- ft -73
ft- 1-73
5- 2-73
•5-31-73
7- 2-73
8- 1-73
9- 5-73
in- 3-73
11- 1-73
17- ft-73
1- 7.-71,
3-- ?-7ft
ft- ft-7ft
5- 8-7ft
6- 5-7ft
7- l-7ft
8- ?-7ft
9- ,ft-7ft
10- 3-7ft
11- 6-7ft
17- 2-7ft
?- 6-75
1- 7-75
ft- 3-75
6- 3-75
r- 1-75
8- 5-75
10- 7-75
11- 5-75
•NTIFI
NUNR
310
339
358
ft.?ft
510
630
702
79ft
819
96ft
1005
121ft
1155
17ft7
1336
1365
11.38
1571
1595
1660
168b
1776
183ft
18ft5
18 9 ft
1983
2020
1968
2107
212ft
2163
22ft2
2265
2291
2290
2320
2330
2336
23ft5
?350
2356
7361
2369
2373
2379
2385
2399
2ft05
2ft09
?'ft?ft
2ft30
2fc33
2ftft2
2ftft3
71.1,70
ER ANH
TfMP
-99.9
9. ft
13.3
15.6
20.0
22.8
22.7
1ft. ft
16.1
11.0
8.1
2.5
ft.O
10.0
18.0
16.0
27.2
2ft. 0
2ft. ft
21.1
20.0
12.2
10.6
-99.0
7.2
12.2
12.2
15.6
2ft. ft
25.0
23. ^
21.1
20.0
-99.0
-99.0
8.9
15.6
-99.0
16.6
21.6
. 20.6
2ft. ft
23.3
18.9
12.2
8.9
7.8
12.2
11.1
18.9
18.9
-99.0
2ft. ft
17.8
LOCATION
COND
ft907
ft953
ftS^l
5ftftft
5670
5875
6937
5380
525ft
ft5M
ftft8ft
ftS87
ft73ft
5053
ft5?5
fc919
ft822
5890
5919
1*851
5056
ft952
ft503
ft677
ft651
ft558
ft6ft8
ft!51
ft982
51?ft
ft695
ftftflS
5085
ft595
ft!58
37ft2
ftft6fl
ftftft8
ftft?8
3618
ft808
',fc21
ft56h
5055
ftOftft
3867
ftlOft
ft279
ft283
ftft76
ft?73
ft710
ft6HB
ft 5 6ft
ft 026
PH
8.02
7.92
7.9ft
8.11
7.90
7.93
8.05
7.95
7.98
7.76
7.75
7.79
7.89
7.81
7.83
7.99
7.71
7.90
7.89
7.90
7.88
7.78
7.71
7.50
7.68
7.76
7.8ft
7.38
7.21
7.93
8.10
8.1,0
8.22
8.27
8.15
8.0ft
7.97
7.85
7.85
8.16
".11
7.79
7.92
7.66
7.72
7.56
7.73
7.53
7.11
6.90
6.70
6.87
7.10
7.26
7'. 8 2
HC03
231
233
2ftft
2ft6
271
269
260
257
228
215
208
230
208
2ft6
2ftft
263
268
265
278
252
262
232
215
191
196
229
238
183
2ftO
255
272
258
236
226
22ft
207
217
2ft 3
255
26?
275
251
267
263
239
230
207
229
19?
266
279
261
208
260
21?
Ct
863
830
876
907
9ft 6
1013
1133
987
865
76ft
721
7ft ft
7 ft ft
866
786
836
806
999
970
86ft
871
825
831
76ft
789
837
767
670
902
lift ft
8ft ft
855
828
708
723
7ft 8
720
676
695
723
76 7
6ft 9
739
917
637
611
62ft
655
585
690
673
681
671
6ft 7
603
SOft POft
Ift85 11.70
IftOft 15.50
1ft85 12.20
1555 8.80
Ift60 13.20
1598 10.90
1621 8.70
Ift73 10.70
1379 12.30
1208 1ft. 10
119ft lft.70
1256 lft.70
1337 13.80
1556 12.ftO
1373 1ft. 10
Ift21 15.00
1ft 7? 16.20
1665 7.80
15ftO 10.10
1377 11.70
Ift33 12.50
1328 1ft. 00
1289 12.30
12ft3 1ft. 20
1318 1ft. 20
1311 13.00
1279 13.90
Ilft7 16.90
1289 1ft. 20
1700 5.20
1356 11.80
1316 10.80.
1365 8.00
1181 ft.ftO
127.2 10,00
1113 15.20
12ftl 1ft. 20
l?ftl lft.70
12ft6 15.ftO
1286 8.20
1322 10.30
1281 12.20
1275 lfl.30
1283 1ft. 00
1120 13.38
10ft3 15.80.
Hft8 1ft. fcO
1192 13.00
Ift6»> 9,00
1168 1ft. 50
1110 15.50
Iftl3-99.00
1385-99.00
12ftO-99.00
1179 lft.70
NO 3
6ft. 6
56.0
56.0
5ft. 5
36.8
39.6
ft?. 8
ft3.0
52.0
53.0
52.0
52.0
52.0
31.0
30.0
27.0
22.0
27.7
31.0
31.0
32.0
ft3.0
55.0
66.0
66.0
ft&.O
ft2.0
ftO.8
55.0
56.8
ft2.0
ftO.O
5ft. 0
23.0
ft9.0
58.0
56.0
ft 5.0
36.0
35.0
27.0
3ft. 0
35.0
38.0
51.0
66.0
60.8
ft9.0
es.o
ftl.O
30.0
32.5
38.8
76.0
53.0
NA
5ft8
570
6ft6
566
ft90
608
635
588
530
ft58
ft56
ft 72
ft 89
553
501
5ftO
553
616
587
533
562
50ft
520
50ft
525
523
ft 96
ft50
5ftO
69ft
5ft3
538
5ft5
ft 81
509
ft68
ft77
fc62
ft 83
51ft
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ft3fr
ft 77
552
ft 50
ft 00
ft36
ftft5
ft 75
ft61
ft 29
ft 69
ft 66
ft 56
ftlft
K
57
ft6
55
6ft
ft9
56
6ft
60
51
ft 6
ft8
ft7
ft8
52
ft7
ft6
5ft
59
57
59
55
ft7
ft&
ft5
ftft
ftft
ftl
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ft2
89
51
1.9
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ftO
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57
ftO
38
39
ft 3
ft&
ft6
ftl
78
ft2
37
ftO
5
ft5
37
36
ft?
39
ft?
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CA
38ft
ft?9
ftOO
ft68
ft62
ft 95
500
ftft?
390
356
3ft9
3ft2
366
ft32
367
ft03
370
ft66
ft67
392
ft28
380
363
336
358
380
370
323
388
ft89
391
386
37ft
331
352
299
3ft 2
319
330
3ftft
370
358
362
339
300
289
310
327
302
378
315
ft03
ftIO
3ft2
T?5
MG
181
166
172
202
193
207
212
193
17ft
152
Ift8
151
156
177
161
168
16ft
188
17ft
158
165
152
15ft
139
Ift8
Ih8
Ift7
131
lft&
195
178
Ift9
15ft
129
139
136
132
IftO
IftO
137
Ift9
130
IftO
166
129
117
120
IftO
Ift3
125
121
138
13ft
126
172
NHft
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2.3
.3
.3
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2.6
2.2
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1.1
.1
.1
.1
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2.0
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1.7
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.1
.1
.1
.1
.1
.1
.1
.1
.1
.1
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r
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1.2
1.1
1.2
1.2
1.1
1.2
1.1
1.3
1.1
-.0
-.0
-.0
-99.0
1.1
-99.0
-99.0
-99.0
-.0
-.0
-.0
-.0
-.0
-.0
-.0
-.0
-.0
-.0
-.0
-.0
-.0
-.0
-.0
-.0
-.0
-.0
-.0
-.0
-.0
-.0
-.0
OS-SUM
3709
3632
3826
39ft8
3787
ft!61
ft3ft5
3925
3569
3160
3086
319ft
3309
3802
3ft01
3587
35ft2
ft!6?
397ft
3551
3689
3ft08
3377
3208
3359
3ftl5
3273
2910
3ft96
ftft98
3551
3ft71
3ft91
3009
3156
2996
3129
3056
3110
3220
33ft9
3070
3211
3517
2860
2692
2855
2938
31ft5
2996
2617
3308
3236
3058
2851
-------
POINT TUFNTIFIFR AND LOCATTON
MO 1A Y9
1?- 1-75
17-10-75
,?.- 3-7f>
3- *-76
*- 1-7- *-70
7- 7-70
8- 6-70
9-11-70
9-11-70
l?-tfi-70
33 15.6
*2 15.6
63 19.7
97 23.6
126 25.6
212 25.6
213 25.6
31? -99.9
LW 9 FLAMINGO HASH 2
(.-15-70
5- I.-70
<>- *-70
7- 7-70
8- 6-70
9-11-70
9-11-70
1P-16-70
1-19-71
*-?3-71
7-26-71
8-31-71
6- 1-7?
7-10-72
31 16.9
37 20.0
6* 23.3
98 20.8
127 22.2
21* 22.2
215 22.2
313 -99.9
3*0 12.8
*66 19.*
652 20.6
73* 21.0
1*60 18.3
1582 21.1
LM 10 STFVENS SPRING
*-15-7fl
5- i»-7()
•)- 5-70
32 16.0
*1 15.6
128 23.3
LW 11 UNNAMED SPRING
V30-70
•3- *-70
f>- 5-70
7- 6-70
*- 5-70
9-11-70
9-11-70
1?-16-70
1-19-71
*-23-71
7-26-71
1-11-71
c;. (,-7?
17 -99.9
*5 18.6
66 2*. 2
99 22.1
129 23,9
186 20.0
187 20.0
31* -99.9
3*3 -99.9
*53 17.2
653 22.8
710 2*.1
1*13 18.3
CONf) PH
381* 7.62
3600 7,*0
3557 7.95
*136 7.75
*Q86 7.50
21S 61E
3765 7.90
.15*6 7.87
263* 7.90
2**6 7.85
1862 7.80
268* 7.82
3028 7.80
3557 7.61
21S 61E
3273 7.62
2819 7.*5
27*1 7.75
2661 7.75
26?6 7.88
29*7 7.81
3312 7.85
3510 7.36
3813 7,51
1579 7.55
1629 7.55
3882 7.*0
35*5 7.19
39*0 7.59
21S 62E
7065 7.70
507* 7.55
997 7.68
21S 62E
*762 7.50
5807 7,*0
*19B 7.75
*2l6 7.25
1555 7.80
*8*6 7.80
56118 7.8*
5300 7.25
5073 7.61
57*6 7.3*
563* 7.27
6072 7.17
*221 7.59
HC03
179
177
173
209
202
13 122
362
356
36*
33*
89
303
290
362
13 121
317
298
27*
285
279
278
283
3*0
338
317
285
303
299
303
31 *11
576
563
112
£1 *3*
359
3*1
365
378
107
3*1
*33
352
391
**5
*21
*52
37*
CL
569
569
5*8
616
616
1
650
3*1
239
270
28
176
20*
22*
1
**5
235
23*
2*7
255
2*7
238
2*1
233
219
253
265
229
252
1
1198
735
26
3
755
991
73*
731
*5
790
833
8*6
797
699
7?6
787
1.66
SO*
1096
1058
1012
1307
12?9
1603
200*
•« 1*56
12*3
1188
1387
1386
2099
1703
1603
158*
1368
1627
1*97
15**
1923
195*
1776
1700
1757
17*7
1898
2605
2655
**9
216*
195*
2*71
2111
988
1906
2076
2285
2*19
23**
2270
2178
1732
PO*
1*.00
15.70
10.50
10.62
11.31
-.10
-.10
-.18
.28
-.18
-.10
-.10
-.10
-.10
-.10
-.10
-.10
.13
-.10
-.10
-.10
-.M
» 20
.1*
.20
.16
-.0*
.31
.25
.28
.10
.18
-.!«
,*0
.18
.30
.18
.16
-.10
1.20
.18
.36
.16
N03
55.0
55.0
53.5
*3.5
31.5
-.5
.7
1.2
1.1
-.5
2.1
-.9
.7
1.8
3.3
3.0
*»o
2.0
7.*
7.2
3.*
3.7
2.8
2.8
3.1
3.6
3.6
-.5
-.*
-.5
-.5
-.*
-.5
2.9
-.5
3.1
-.9
1.1
.2
.2
.1
1.3
.8
NA
395
793
*60
**2
*30
2*5
30*
196
170
37
135
1*8
296
2*5
206
201
187
188
188
199
250
301
232
218
213
206
215
615
660
25
*56
*66
520
*08
33
*38
**9
519
578
*87
*71
*83
301
K
3*
33
30
37
3*
28
27
25
21
10
21
23
36
17
17
17
15
17
17
18
23
25
22
17
19
20
19
*5
79
10
55
5*
75
*9
13
53
56
5S
61
62
52
55
39
Oft
300
300
267
350
350
*75
*5*
262
237
*70
3*8
350
**5
395
368
272
250
310
338
326
376
356
373
3*8
365
357
372
579
612
195
505
518
610
562
38
525
*60
*98
596
568
530
553
*35
MG
112
113
98
133
126
297
280
2*2
266
33
171
175
250
250
252
238
2*3
2*5
220
239
266
26*
2*9
2*6
252
236
251
5*0
5*0
20
332
336
366
300
25
300
301
318
3*8
308
302
311
21*
NH*
.1
.1
.1
.1
.1
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.1
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
f
-.0
-.0
-.0
-.0
-.0
1.2
.9
.7
.8
.3
.7
.6
.8
.7
.6
.5
.6
.6
.6
.6
1.7
.7
.7
.6
.6
.9
.6
3.5
3.*
.3
2.5
2.*
2.6
2.5
.3
1.6
1.8
.7
1.8
2.3
1.9
1.7
1.8
OS-SUM
2663
2625
256*
30*3
2927
3*78
3586
2601
2373
1810
2392
2*29
3539
321*
2831
2683
2*55
2782
2651
2711
3251
330*
3031
2926
302*
29*7
3161
5861
5561
781
***7
**00
*958
*353
1195
*18*
*390
*699
*993
*690
*560
*593
337*
-------
POINT lOFNTIFTER AND LOCATION
MO nn YR
7-10-7?
NUMB
1577
LW 12 r.PAPFVINE
4-15-70
5- i»-71
6- 5-70
7- 6-7n
n- 5-70
9-11-70
9-11-71)
4-23-71.
7-26-71
8-31-71
I?- 3-71
1- 4-72
?- 1-72
7-IB-7?
34
40
67
100
130
IRK
189
1.51.
651.
731
921
1074
1180
1576
TE1P
23.3
SPRTNG
20.3
21.1
22.2
20.6
20.8
20.8
20.8
20.6
22.2
24.5
15.0
16.9
19.0
23.3
COND
1.356
2331
2206
2116
2155
2173
?400
2585
2579
2576
252".
2656
2555
2611.
2653
LM 13 HHIT. MFSA SP. 1
5-10-70
<=>- U-70
8- 3-70
7- 6-70
8- 5-70
1-11-70
<»-tl-7n
1-19-71
7-26-71
8-M-71
11-11-71
12- 2-71
1- 3-72
2- 1-72
3- 3-72
5- (.-72
6- 1-7?
7-10-72
8- 7-72
9- 7-7Z
10- 1-72
11- 7-7?
1?- 4-72
1- 4-73
2- 1-73
1- 5-73
4- 1-73
5- 3-73
5-31-73
7- 3-73
8- 1-73
1*
43
69
101
131
196
197
31.7
637
729
810
920
1070
1181
1271.
1397
11.68
156?
1637
1662
1676
1811
18<«3
1«58
1923
2003
1964
2036
2111
2132
2183
-99.9
20
2*9
250
243
279
291
291
291
307
307
294
286
?70
259
265
261.
268
298
236
188
CL
1.1.1
1
334
166
151
158
159
160
Id 8
159
162
162
168
163
163
161
1
1245
1390
1270
1100
1361.
1271.
121.3
1121
1187
1286
1112
917
1068
993
1069
1126
1242
1252
1223
1249
1258
1146
1130
1081
1055
1066
1066
1098
1244
1307
1287
SOI.
1701.
1002
1202
1124
997
1178
1108
1092
1145
1205
1147
1137
1144
1139
1171
1401
1353
1734
1214
1617
1667
1834
1829
2038
2058
1822
1841
1775
1757
175?
"1880
1986
2104
1992
2100
1955
1888
1843
1827
18??
1798
1783
1834
1986
2180
221?
P04
.18
.12
-.10
-.10
.25
-.10
-.10
.25
.16
-.10
-.18
.20
-.10
-.10
.12
-.10
-.10
.11
N03
-.1
2.2
2.7
1.9
2.2
1.8
2.4
2.2
2.0
1.7
1.9
2.1
2.9
2.5
1.1
5.1
1.3
2.8
.15-100.0
.21
.20
.16
-.10
-.10
-.10
-.10
-.10
-.10
-.10
-.10
-.04
-.04
-.04
-.08
.08
-.04
-.04
.06
-.84
-.04
-.04
.16
-.0'
-.04
-.04
-.04
-.5
.9
1.5
6.5
3.4
1.4
4.3
17.0
6.6
6.6
6.3
3.9
2.4
1.9
2.6
1.2
.6
1.5
3.8
6.5
7.4
6.3
5.1
4.3
3.1
.0
1.8
NA
293
120
126
136
121
128
129
132
164
131
121
132
127
124
123
470
514
588
488
51)0
525
588
632
678
664
592
606
544
536
536
586
655
630
631
647
670
601
592
580
564
557
549
574
628
699
696
K
35
41
21
21
22
24
22
24
22
22
24
24
23
21
21
42
46
47
43
62
53
59
54
62
68
57
59
56
53
57
60
65
65
63
68
74
61
59
57
57
53
51
56
58
98
6
CA
420
304
291
287
223
267
275
272
285
277
275
286
278
275
271
548
560
580
426
610
590
590
598
583
626
518
476
546
519
511
559
569
591
589
592
590
555
542
514
519
534
527
538
589
589
606
MG
207
150
158
147
150
152
136
145
144
148
147
143
141
143
144
250
246
292
230
290
250
246
243
291
294
258
227
245
238
239
255
280
282
283
283
283
263
256
243
240
238
237
253
285
296
294
NH4 F
.1 1.8
.0 1.0
.0 1.0
.0 .9
.0 1.0
.0 1.1
.0 .9
.0 .0
.0 .0
.0 .0
.0 .0
.0 .0
.0 1.0
.0 1.0
.1 1.0
.0 1.2
.0 1.3
.0 1.3
.0 1.2
.0 1.3
.0 1.3
.0 1.5
.0 1.3
.0 1.3
.0 1.5
.0 1.2
.0 1.0
.0 1.3
.0 1.4
.0 1.3
.0 1.4
.0 1.4
.0 1.4
.0 1.4
.0 1.4
.0 1.3
.0 1.4
.0 1.4
.0 1.4
.0 -99.0
.0 -99.0
.0 -99.0
.1 -99.0
.2 1.3
.1 -99.0
.1 -99.0
OS-SUM
3291
2062
2075
1978
1783
2018
1945
1927
2030
2060
1988
2004
1989
1980
2004
4077
4219
4629
3608
4535
4477
4681
4591
4983
5141
4496
4263
4364
4227
4292
4609
4944
5070
4928
5093
4983
4661
4568
4443
4391
4382
4349
4490
4941
5285
5195
-------
POI1T InFNTIFIF.R AN&
MO- HA YR NUMB TEMP HONn
PH- HC03
CL
S04 P04
NA
C«
MG NH4
F OS-SUM
1.4 HHIT. HCSA SP.
22S 6?E 04- 32? 1
(Jl
5-19-79
(>- 5-7i>
7- 6-7IJ
ft- 5-7&
9-12-70
9-12-70
t-19-71
70 17.7
71 25.6^
t02 23.3
132 25.8
198 23.1
199 23.3
341 13.9
LW 15 HHITNFY MESA SEEP
3-30-70
5- l|-70
6- 5-70
7- 6-70
8- 5-70
9-11-70
9-11-70
1-19-71
4-22-71
6-lli-71
7-26-71
8-31-71
11-11-71
1?- 2-71
1- 3-72
2- 1-72
3- 3-72
5- «i-72
6- 1-72
7-10-72
8- 7-72
9- 7-7?
10- 1-72
11- 7-72
12- 4-72
1- 4-73
2- 1-73
3- 5-73
<»- 1-73
5- 3-73
5- .11-73
7- 2-73
8- 1-71
15 -99.9
55 20.0
72 26.5
103 21.7
133 22.5
200 23.1
201 23.1
342 IB. 3
433 20.0
5i»l 21*5
636 23.9
728 24.0
809 21.1
919 13.0
1069 20.0
lilt! 13.0
12/3 -99.0
1398 21.0
1467 21.1
51". 0 23.3
1636 25.6
1661 21t.lt
1678 23.9
1B12 20.0
1844 18.9
1859 -99.0
1922 18.3
2002 18.9
1963 15.6
2035 -99.0
2110 21.1
2133 25.6
2181 -99. n
LW 16 CLARK STP OUTFALL
3-30-70
5- 4-70
6- 6-70
7- 6-70
It- 5-70
9-11-70
16 -99.9
57 15.5
73 21.1
1Q1> 24.4
13it 25.8
190 22.2
154*
1548
161&
2145
16F.lt
1738
4818
7.40
7.25
r.55
7.39
8.00
8.02
7.74
22S 626
5on«i
5500
4157
4237
(.318
5234
5699
5699
571|6
5931
571l|
6172
5831
6132
5726
5917
5411
5513
5466
5840
5899
5412
5511
5829
5634
5712
5537
5821
5508
5420
5570
5544
5406
7.60
7.71
7.65
7.75
7.82
7.81
7.96
7.50
7.27
7.45
7.75
7.95
7.69
7.62
7.78
7.63
7.80
7.66
7.74
7.79
7.81
7.85
7.66
7.55
7.71
7,6?
7.49
7.84
7.71
7.61
7.88
7.84
7.87
21S 62E
4887
4805
4241
3418
16?4
4507
6.80
5.75
6.50
6,")5
7.99
7.00
257~
265
269
297
239
240
247
04 233
232
225
232
232
203
236
238
214
240
241
246
244
Z39
261
238
243
239
249
247
254
253
249
252
255
253
251
251
252
254
243
252
236
188
27 342
107
25
73
114
120
82
206
215
228
393
230
2? 3
895
1
1000
975
930
966
972
975
1022
951
931
946
965
997
916
1099
915
995
917
898
893
898
902
893
894
889
889
883
868
883
870
874
902
886
1157
1
1200
952
980
825
4(1
831
409
596
418
439
329
402
1246
1603
1623
1712
1468
1*47
1627
1750
1843
1831
1796
1863.
1956
1841
1754
1828
1818
1812
1874
1843
1887
1805
1903
1830
1719
1791
1818
1820
1797
180?
1799
1791
1846
1864
1303
1353
1431
1115
968
1337
.13
.11
.38
.33
.IS
.10
-.10
-.10
-.18
-.10
-.10
-.10
-.10
.10
-.10
-.10
-.10
-.10
-.10
-.10
-.10
-.10
-.10
-.10
-.04
.08
-.04
•.04
-.04
-.04
-.04
.08
-.04
-.04
-.04
-.04
-.04
-.04
-.04
-.04
1.53
1.14
3.38
3.30
.38
.70
3.3
2.0
-.5
-.5
.4
-.9
2.7
13.3
5.9
13.4
14.2
22.1
18.6
13.9
13.9
17.4
14.2
20.0
16.0
17.0
5.5
20.0
19.0
19.0
18.0
17.9
17.0
18.2
16.0
18.8
19.0
22.0
26. «
20.2
22.0
22.0
21.7
21.0
22.0
21.0
36.3
53.2
34.1
13.7
1.5
43.9
120-
132
126
166
129
137
347
553
586
656
602
625
550
600
603
595
520
585
632
.596
594
594
574
583
585
602
587
569
565
587
583
587
580
565
567
573
564
570
575
611
675
634
798
520
52
575
19
21
2t
28
23
24
6&
50
54
66
52
60
56
64
55
57
57
56
63
62
63
59
55
57
59
61
57
58
58
60
58
56
57
57
55
54
56
53
81
53
46
50
63
44
16
50
t32
150
156
?05
140
138
491
438
407
300
368
410
440
444
492
429
474
448
471
445
535
448
449
449
459
444
452
453
453
463
451
443
440
441
456
464
450
454
429
445
338
344
270
290
390
3
-------
PHtNT TWNTIFIFR AND
MO n* YP
9-11-70
1?-15-70
1-19-71
3-10-71
3-30-71
U-22-71
6-11-71
7- 7-71
7-26-71
S-30-71
9-28-71
11-10-71
12- 2-71
1- 3-72
?.- 1-72
3- 2-72
<•- 6-72
5- 3-72
6- 1-72
7-10-72
8- 6-72
9- 6-72
10- 1-7?
11- 8-7?
12- 4-72
1- li-73
1-31-73
^- 4-73
«.- 1-73
5- 2-73
6- 1-73
7- 2-73
1- 1-73
10- 2-73
11- 1-73
12- 4-73
1- 2-74
NOMB TEHP
191 22.2
.'15 -99.9
31,1. Jli.l,
~ 5-70
7- 6-7(1
fl- 5-70
q-to-71
q-^o-7n
11 -99.9
20 24.0-
44 27.0
75 33.7
105 26.2
136 31.1
1«3 31.7
182 31.7
LOCATION
CONO
1.953
5955
5579
5183
"•687
4056
1.336
6102
1.962
6467
1.912
5705
1.713
51.38
5046
5390
5395
3126
1.80?
54 1.1.
'6090
6525
6370
7067
6662
31.15
5027
«»920
561.9
1.721
6168
5065
5025
5003
5237
5198
(.179
A
3680
21.651
271.99
2775
B
101.29
B316
20651
12372
1.530
9246
43«i4
389R
PH
7.18
7.29
7.22
6,98
7.06
7.27
6.85
6.1.0
5,71.
6.79
6,28
6.98
6.99
6.83
7.20
6.70
7.51
8.65
7.57
6,89
6.63
7.1.6
8.01.
8.1.2
8.06
9.32
8.60
6.51
7.12
7.29
8.86
6.67
4.86
7.1.1
7*11.
7.11
7.12
22S 62E
11.55
13.57
13.12
11.1.5
22S 62E
12.10
11.00
12.50
12.10
11 .10
1?.53
12.6^
I'.io
HC03
88
17
8
107
106
47
71
30
23
1.3
26
94
51.
51
66
51.
116
32
163
183
6*
115
236
220
296
21.
112
126
21.0
214
260
63
1.
74
lit
86
86
11 413
53
-77
-77
-77
02 145
-77
-77
-77
-77
50
-77
-77
-77
CL
882
1181
1149
916
888
775
721
1096
746
917
805
939
783
1022
876
1300
1050
524
868
922
1096
1669
1133
1225
1160
565
907
732
1122
799
1087
817
944
102
970
1160
1827
1
722
681
805
499
1
846
1037
1506
1670
652
1055
523
565
S04
1420
1723
1770
1379
1335
97«
1066
1535
1611
1534
1350
1550
1195
1367
1273
955
1461
807
1264
1384
1453
913
1916
1871
1836
79«
1320
1417
1181
1300
1991
1608
1668
1445
1633
1732
1369
319
351
354
406
401
501
409
460
385
359
392
396
P04 N03
.92 40.9
.69 85.0
1.44 27.5
2.24 3.0
3.66 23.0
1.76 16.8
1.90 13.2
1.90 47.8
4.50 29.3
2.12 123.0
2.40 88.0
4.10 22.0
3.20 116.0
3.40 69.0
3.80 114.0
4.00 95.0
2.70 39.0
3.40 6.4
2.20 37.0
.86 20.5
4.30 102.0
1.80 13.
4.20 25.
3.60 65.
4.20 17.
1.10 4.
2,40 9.
7.30 3.
3.30 4.
5.50 18.1
5.20 14.2
2.40 37.0
2.50 13.3
.63 4.5
3.60 30.0
3.60 97.0
4.10 41.0
.11 7.8
-.10 24. 6
-.10 26.4
.13 3.2
22.70 12.9
2.30 20.8
.30 10.6
.54 1.3
-.10 15.7
.35 19.0
-.10 9.9
-.10 15.1
NA
542
765
786
600
587
476
456
721
671
743
673
743
582
683
628
875
738
375
673
705
786
1060
931
975
910
412
695
610
797
624
785
641
744
594
745
866
682
725
3150
3224
5f5
1190
1175
2470
90
770
J325
830
725
K
57
67
54
57
57
47
42
58
44
58
51
55
44
49
48
34
56
26
47
51
53
42
71
72
70
28
47
43
41
44
52
61
51
40
49
59
44
6
7
6
4
6
7
6
11
56
6
6
1
CA
378
374
430
323
310
260
271
409
334
374
308
321
248
368
292
246
358
205
326
318
392
275
418
474
442
196
340
292
331
297
445
388
413
386
409
449
338
18
2
24
3
66
33
20
1
50
105
1
55
MC
103
178
159
147
139
97
81
124
102
116
101
142
113
135
128
99
130
59
87
123
115
102
157
168
166
74
97
131
114
126
189
124
109
98
119
158
114
11
0
10
1
17
15
6
0
22
30
0
-0
NH4 F
.0 1.0
.0 1.2
10.7 1.3
10.7 1.5
10.7 1.5
10.7 1.1
11.3 .9
11.3 1.1
13.6 1.0
4.4 1.1
4.4 1.0
21.0 1.2
21.0 .9
21.0 1.0
21.0 l.t
21.0 .8
8.1 1.2
8.4 .5
3.2 .9
3.0 1.1
4.0 1.0
6.6 .6
3.1 1.1
4.8 1.2
3.5 1.3
13.0 .6
1.8 -99.0
13.0 -99.0
.4 -99.0
3.5 -99.0
14.0 1.5
3.4 -99.0
14.0 -99.0
14.0 -.0
14.0 -.0
14.0 -.0
14.0 -.0
.0 .3
.0 .4
.0 .3
.0 .3
.0 .1
.0 .4
.0 .4
.0 .3
.0 .2
.0 .4
.0 .3
.0 .3
DS-SUN
3'»68
4383
4393
3492
3407
2686
2699
4020
3568
3894
3397
3845
3132
3743
3417
3656
3902
2030
3389
3619
4038
4139
4676
4968
4755
2105
3474
3312
3712
3322
4631
3713
3961
3421
3984
4581
3676
1835
4216
4450
1501
2563
2792
4429
2234
2176
2900
1762
1757
-------
POINT IDENTIFIER ANO LOCATION
MO HA YR
1?-15-70
NUM8 TEMP
316 -99.9
CONfl
11065
LM 19 LV RLOG MAT FOND
1-11-7(1
5- *-7!1
6- 5-70
7- 6-70
8- 5-70
9-10-70
1-10-70
17-15-70
*-?3-71
5-17-71
7-26-71
"5-10-71
11-10-71
LM 20 MENU
7- 8-70
8- 7-70
9-10-70
9-10-70
12-15-70
1-19-71
*-23-7i
6-11-71
7-26-71
8-10-71
9-23-71
11-10-71
12- 2-71
1- 3-7?
2- 2-72
?1 16.5
56 19.8
79 21,. 6
106 26.7
137 26.9
1«0 28.3
1S1 2R.3
319 -99.9
*61 21.7
".69 21.7
6*5 26.1
718 30.0
833 13.3
101*0
9525
8631
6023
5851
9356
10970
9550
8275
9622
8120
6770
It 9,18
STP GH (WAIN
116 2".. 2
138 26.1
176 25.0
177 25.0
319 -99.9
3*8 23.9
*67 23.0
530 22.0
6>i3 2*.*
716 25.0
782 2lt.O
831 2*i*
912 2*.0
1060 2*.0
1187 2*.0
1- 2-72 11665 -99.0
5- *-72
7-10-7'
11- 8-7?
1?-
-------
-J
00
pntMT n*-
MO r)A Y9
1?-15-7T
1-19-71
4-?3-7i
6-11-71
?-?6-71
•1-10-71
11-10-71
1?- 2-71
1- 3-72
?- 2-7?
3- 2-72
<•- 6-72
5- 4-72
6- 1-72
7-10-7?
n- 6-7r
10- 1-72
11- 8-72
12- 4-72
1- 4-73
3- li-7?!
4- 1-73
5- 2-73
5-31-73
7- 2-73
>»- 1-73
1- 5-73
10- 3-73
11- 1-73
12- Ii-73
1- 2-74
NTJFTER ANO
NUMO TEMP
*?0 -99.9
31,9 21.1
4&fl ii.. n
531 27.0
F.44 26.1
717 25.0
832 13.3
913 9.0
1061 10.0
1188 9.0
1265 -99.0
1357 18.9
1388 22.5
!Ct62 28.3
1569 25.0
1630 31.1
1677 20.0
1851 llt.lt
1832 13.3
1853 -99.0
1989 !<».<*
2008 13.9
1971 22.2
2103 Z6.1
2130 29.5
2171 28.9
2249 25.6
2267 24.4
2290 -99. 0
2292 -99.0
2318 8.3
LOCftTIOM
noNn
3786
1681
1.137
1.000
3489
36M
3425
3375
3078
3148
7927
3102
33«i5
33<»1
31.25
3H.O
2993
3033
•IMS
3187
3728
3527
3285
3338
3197
261.3
Z551
2761
2599
27D3
2599
LW 22 TITSNIUM HITCH
7- 8-70
8- 5-70
9-10-71
9-10-70
l?-15-7fl
1-19-71
?-18-7t
".-23-71
6-11-71
7-26-71
1-30-71
9-23-71
11-10-71
1?- 1-71
1- 3-72
1-19-7?
t-?5-72
1-37-7?
t-30-7?
?- 2-7?
7- 4-7?
118 26.4
140 27.8
168 28.9
169 28.9
321 -99.9
350 20.6
368 24.4
1.58 25.6
536 29.0
639 26.1
709 26.7
780 27,0
829 22.2
905 25.0
1065 l«.l
-0 -99.0
-0 -99.0
-0 -99.0
-
-------
VQ
POINT inENTIFIER AND LOCATION
MO HA YR
3- ?-72
•'- 9-7?
3-11-7?
^-15-7?
3-19-72
T-?3-72
*- 6-7?
*- 2-7?
f>- 1-7?
7-10-72
8- 6-7?
q- 7-72
10- 2-77
11- 8-7?
1?- *-72
1- *-73
3- *-73
*- 1-73
5-U-73
7- 2-73
8- 1-73
9- 5-73
10- 2-73
11- 1-73
12- *-73
1- 2-7*
3- 2-7*
*- *-7*
5- 8-7*
6- 5-7*
7- 2-7*
8- 2-7*
q- *-7*
10- 3-7*
11- 6-7*
1?- 2-7*
2- 6-75
•?- 7-75
*- 3-75
6- 3-75
7- 1-75
8- 5-75
9- *-75
10- 7-75
1?- 3-75
12-30-75
?- 5-76
3- *-76
*- 1-76
NUMB
1268
-0
-'0
-0
-0
-0
1353
1*36
1*63
156*
1633
166*
1680
1819
1835
1855
1990
200*
2109
2127
2168
22*7
2266
2289
2291
2319
2329
2335
23*3
235*
2360
2362
2368
237*
2380
2389
2*00
2*06
2*10
2*23
2*29
2*3*
2**1
2***
2*56
2*58
2*66
2*70
?*75
TEMP
-99.0
-99. 0
-99.9
-99.9
-99.9
-99.9
21.7
26.7
26.7
25.6
27.8
26.7
27.8
23.9
20.0
-99.0
75.0
19.*
25.0
29.*
25.6
27.8
25.6
-99.0
-99.0
16.6
23.3
-99.0
-99.0
28.9
20.0
29.*
29.*
27.8
25.6
23.3
19.*
20.0
20.0
26.1
25.6
-99.0
26.7
2*.*
22.2
2*.*
19.0
18.0
25.0
CON"
2232
138*8
891*
9268
6869
89?7
2088*
10317
5711
6632
5*88
93**
5238
9*71
12*1.0
52*6
9579
9550
5*80
9891
7628
7968
6*55
1351*
7692
20790
1*3**
6223
*77*
769
397*
5735
15899
***8
38*18
91*9
9119
13088
8313
*7813
11190
7718
7880
9922
7285
7668
37095
18903
38*2
LI 13 "11 STP OUTFALL
7- 8-70
8- 7-70
q-in-7n
119
1*1
170
27.5
29.7
28.3
2071
1**0
1*63
PH
8.8*
11.30
7.76
9.15
2.**
2.38
1.32
2.27
2.*8
2.30
2.*0
11.21
9.75
2.30
2.58
8.50
13.15
1.97
2.78
1.76
1.9*
2.70
1.99
1.75
1.99
1.28
t.82
3.82
2.64
3.36
11.62
3.91
12.55
9.05
1.12
2.19
2.2*
7.05
2.20
1.20
1.90
2,00
2.1*
2.23
2.30
2.51
9.00
8.30
2.30
22S 63E
7.25
7.59
6.7?
HC03
60
-77
71
39
-77
-77
-77
-77
-77
-77
-77
-77
172
-77
-77
68
-77
-77
-77
*77
-77
0
-77
-77
-77
-77
-77
-77
-77
-77
197
-77
2757
112
-77
-77
-77
7*
-77
-77
-77
-77
-77
-77
-77
-77
*00
168
-77
CL
*13
3925
2393
?5?3
1563
23M
29*5
2873
1*3*
979
1080
20*7
1278
21*6
3036
1290
1*0*0
1755
1379
39*
902
1208
76*
1*63
1550
2963
2875
1790
1063
500
513
1500
15*7
936
*909
1929
2375
3582
1*88
3725
1200
1*00
1955
2525
1760
2175
1*300
6750
535
SO* POU N03
*39 -.10 11.8
7»3 -.10 118.0
998 -.10 56.0
83* -.10 169.0
872 -.10 1*8.0
8*7 .8* 155.0
23*9 10.00 113.0
10*8 -.0* 279.0
*05 .1* 127.0
9*6 .*? 162.0
*82 l.*0 133.0
1678 -.0* 6.0
*1* 30.00 .9
895 -.0* 191.0
5*9 .52 .157.0
*12 .10 188.0
1628 2.00 212.0
629 1.50 8*.0
60% .66 117.0
2212 3.30 8.*
1225 .60 96.0
132* -.0* 1*2.0
911 .69 .*
1988 .26198.0
757130.00 213.0
36* 1*.00 13.3
113« .06 199.0
710 .0* 1*7.9
561 .06 128.0
629 .1* 7.2
625 .I* 30.0
509 .06 3.0
950 -.02 3.0
363 .03 250.0
1117 2.10 290.0
1121 .38 277.0
303 ,*1 273.0
1*88 .16 305.0
8?1 .12 80.0
7082 *.QO 290.0
2113 2.81 59.0
688-99.00 170.0
5*0-99.00 17*. 0
*39-99.00 322.0
335 .05 1*7*0
308 -.02 227.0
539 -.02 390.0
356 .02 305.0
281 -.02 19.2
NA
32*
3153
1605
1667
931
1022
1*76
1180
332
286
191
2151
63*
1117
15*5
592
16875
620
*67
379
19*
*85
370
339
359
323
1296
662
287
*22
757
5*5
2618
890
1215
887
515
2**0
***
913
572
2*1
563
925
*90
*28
8*20
3200
180
K
12
26
27
27
10
13
29
7
8
5
5
9
20
12
7
6
23
6
39
26
6
13
8
9
10
6
11
8
7
5
7
10
,15
9
12
8
8
1
7
10
9
23
23
7
6
6
7
5
*
CA
86
19
16*
89
120
196
193
1*5
1*3
107
102
25
70
93
110
150
28
10*
101
126
112
1*3
108
116
150
127
126
91
98
75
19
112
5
23
211
96
80
8*
98
102
163
99
100
89
93
82
2*
68
7*
Mf,
• 39
1
112
208
157
310
ZOO
*92
291
266
278
-0
262
279
280
6
16
173
2*7
*8
250
25*
53
273
330
53
281
312
265
25
5
286
-0
15
356
3*6
502
38*
2*7
*06
209
305
300
358
20*
*09
333
6*6
31
NH*
.2
.2
. ?
.2
.2
.2
.2
.2
9.*
9.*
9.*
9.*
9.*
9.*
9.*
5.7
5.7
*.*
12.0
1.*
9.9
5*.0
5*.0
5*.0
5*.0
5*.0
15.8
19.3
13.1
13.1
13.1
13.1
13.1
13.1
13.1
13.1
13.1
13.1
13.1
13.1
13.1
13.1
13.1
13.1
13.1
13.1
13.1
13.1
13.1
F
.3
.1
.*
.*
.2
.3
.3
.3
.*
.3
.*
2.3
.5
.6
.6
.5
-99.0
-99.0
.5
-99.0
-99.0
-99.0
-.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
OS-SUM
135*
8025
5390
5537
3802
*888
7316
602*
27*9
2762
2283
5928
2803
*7*3
569*
268*
32822
3377
2967
3198
2796
3623
2270
***0
3553
3917
59*2
36*9
2*22
1677
2065
2978
6506
2555
8125
*678
*069
833*
3198
125*5
*3*1
2939
3668
*678
30*8
36*8
2*223
11*26
1137
07 122 1
3*2
106
10?
265
1*6
1*6
390-99.99-100.0
329 36. 80 51.0
38* 19.23 5*,0
292
168
176
12
11
11
8*
93
92
35
35
32
.0
.0
.0
.3
.*
.*
12*6
923
965
-------
00
o
POINT TnFNTTFIER UNO LOCATION
MO na YF>
q-to-70
12-15-70
1-19-71
6-14-71
1- '0-71
10- 1-71
11-10-71
1»- 2-71
1- 3-7?
3- 3-73
4- 6-73
5- 3-72
6- 1-7?
7-10-73
8- 6-73
LH 25 NEW
3-31-70
5- 4-70
6- 4-70
7- 7-70
8- 6-70
12-15-70
1-19-71
3-30-71
7- 7-71
8-30-71
12- 1-71
1- 3-72
2- 1-7?
•5- 4-73
7-11-73
WHO TEW
171 3S.3
322 -99.9
351 18.3
540 35.0
710 38.3
781 34.4
B28 32.8
914 18.0
1064 7.3
1267 -99.9
1355 18.9
1433 24.4
1463 36.1
1563 36.1
If34 39.4
RS DISCHAR6F
27 19.0
36 23.4
80 37.4
108 31.1
144 31.1
333 -99.9
353 17.3
403 23.0
616 33.1
733 38.9
898 33.0
1036 14.0
1170 15.0
1379 37.0
1586 32.6
cawrv
147?
1721
1613
1918
1951
1644
1744
1751
1570
1537
1505
1521
1471
1643
1615
3218
2251
3077
3684
3455
3313
3533
30f>4
3027
3431
3990
3914
2929
3074
3336
LH 26 SUNRISE STA OUTFL
3-31-70
5- 4-70
6- 4-70
7- 7-70
8- 6-70
9-11-70
0-11-70
12-15-70
1-19-71
^-'0-71
4-22-71
6-11-71
7- 7-71
S-30-71
9-28-71
11-10-71
12- t-71
t- 3-7?
2- 1-7?
38 25.0
46 27.8
81 33.6
109 36.4
145 37.8
208 36.7
209 36.7
3JI, -99.0
353 31.1
401 20.5
447 10.6
523 36.0
61* 31.9
732 37.6
793 -99.0
R39 31.1
89" 38.0
1037 34.0
1171 36.0
3380
3943
3412
3377
3217
3925
4240
4862
3419
4813
1695
3586
6444
5685
3318
4308
5169
5192
4796
P«
6.79
7.38
7.30
7.55
7.10
7.31
7.36
7.53
7.44
7.33
7.27
7.31
7.38
7.06
7.08
21S 62E
7.75
7.35
7.65
7.75
7.98
7.84
7.25
7.71
7.90
8.01
7.46
7.67
8.04
7.84
7.59
31S 63F
6.02
6.05
6.45
6.95
r.48
6.91
6.98
7.11
7.25
7.03
7.51
10.00
9.35
8.90
7.98
6.93
6.77
6.69
7. 58
HC03
93
81
66
314
216
372
349
270
332
276
370
348
506
399
372
11 323
175
185
138
178
166
177
144
166
178
152
175
203
200
182
155
10 422
27
21
40
70
66
63
60
24
3
77
108
9
53
34
75
50
46
40
53
CL
134
193
156
160
197
163
167
201
163
160
159
171
161
166
144
1
432
124
344
313
172
188
319
189
138
185
191
159
156
316
229
1
660
847
706
692
631
753
795
953
656
916
384
376
1230
1042
636
814
1094
1049
9*4
S04 P04 N03
386 20.90 64.9
424 29.70 63.8
393 26.20 4.8
363 30.10 .6
333 39.30 .9
346 32.80 .1
327 34.20 .2
329 40.00 .4
349 37.00 2.0
335 33.00 .9
338 19.40 3.1
338 33.00 .6
188 33.00 1.0
345 31.00 .2
357 38.80 .4
1453 -.10 41.5
1303 .10 23.3
1431 .11 29.9
1352 .3? 23.0
1397 -.10 30.4
1675 -.10 46.4
1562 -.10 41.0
1397 -.10 30.0
1399 -.10 13.3
1471 -.10 14.0
1*17 -.10 27.0
1386 .14 19.0
1372 -.10 17.0
1466 .90 21.9
1515 .10 23.3
802 3.10 80.3
501 3.84 125.6
664 2.64 153.3
809 3.16 6.9
679 4.76 155.1
1059 3.30 82.0
1061 3.37 109.6
932 4.60 167.5
651 6.12 116.3
1020 7.30 145.0
395 1.65 31.7
538 .20 5.3
1415 .68 44.0
1035 1.80 113.!)
617 .76 95.0
861 3.30 94.0
1079 4.50 255.0
1091 4.00 197.0
974 6.70 202.0
NA
178
193
179
208
193
188
191
197
186
170
168
175
199
167
174
235
180
369
318
183
316
380
325
303
221
214
203
213
235
339
383
482
448
456
364
500
544
570
403
538
153
308
904
669
453
541
695
664
583
K
12
17
16
12
13
12
13
14
13
11
11
11
13
11
11
33
14
14
17
16
16
17
19
14
17
19
12
12
16
17
35
12
43
43
45
47
54
53
38
59
30
23
77
59
37
49
66
55
53
Cft
94
96
1D4
87
83
99
82
88
86
84
89
93
94
97
88
391
253
233
337
370
403
366
398
299
393
332
286
272
309
304
240
234
230
228
250
305
320
295
208
296
103
134
379
362
204
356
360
340
296
MG
35
35
38
33
32
33
33
34
33
32
34
32
37
32
32
180
153
183
167
135
165
171
161
163
166
156
158
159
154
163
66
75
63
78
68
85
94
118
84
138
34
33
79
53
39
83
131
131
110
NH4
.0
.0
15.8
23.3
36.4
36.0
28.0
31.0
36.5
39.0
37.0
36.0
18.0
18.0
16.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
6.4
6.4
6.4
4.8
4.8
.8
.8
8.0
8.0
2.0
2.1
F r
.4
.4
.5
.6
.5
.6
.5
.6
.4
.7
.7
.9
1.3
.9
.7
1.3
.3
.1
.4
.3
.2
1.1
1.3
1.5
.9
1.3
1.3
1.4
1.4
1.4
2.0
3.1
1.7
1.1
1.2
1.3
1.3
2.9
2.3
2.1
.9
.4
2.3
1.9
.5
1.7
2.1
2.1
3.7
tS-SUM
971
1091
965
1070
1013
1034
999
1067
1008
990
980
1003
994
1008
997
3833
3140
3573
2317
2176
2798
2828
2412
2316
2443
2434
2335
2301
2509
2567
2323
2293
2331
3353
3?30
3866
3011
3137
3172
3156
973
1417
4163
3354
3109
3733
3707
3545
3189
-------
P1TNT IOFNTTFIE* AND
MO HA YR
>t- 5-7?
5- 50
525
611
612
720
806
837
901
1056
1171.
1260
1349
1383
1457
1535
1627
16S4
-If. 9 7
TFHP
3^.6
2B.5
34.4
-99.0
37.8
31.1
32.2
2?. 2
26.7
-99.0
25.6
25.6
18.3
13.9
28.9
31.1
34.4
32.2
31.1
36.7
33.3
-99.0
-99.0
2.2
LOCATION
COND
5119
5877
6017
1*501,
70?3
5831
5208
9"t71
5480
6332
5600
5600
2403
3204
4456
59?8
7992
6997
6767
1,385
6089
5198
5509
1362
STP EFFL
23.0
23. 4
25.6
?7.8
28.9
28.9
28.9
-99.9
22.8
22.0
22.8
29.0
23.8
-99.9
28.9
26.1
25.0
22.0
18.0
20.0
-99.0
23.9
2>i.O
26.1
-99.0
31.1
26.7
?8.3
202<»
24*1
1968
1617
1866
21?6
2154
2120
1985
2200
1768
2517
2597
2441
29?1
2311
2290
2331
2432
225?
?44?
18*4
2449
?340
?178
2468
Z155
2114
PH
9.74
T.93
6.85
7.11
6.97
7.01
7.24
10.10
7.71
10.77
8.27
8.27
7.67
7.30
7. 92
7.14
11.90
9.70
11.11
7.60
7.36
7.44
7,62
7.93
21S 62E
7.23
6*98
6.85
6.90
7.88
6.90
A. 69
7.56
7.39
7.37
7.29
7.30
7.22
7.40
7.49
7.52
7.33
7.23
7.32
7.51
7.37
7.52
7.38
7.14
7.21
7.22
7.11
7.32
HC03
-77
82
88
75
164
109
101
-77
264
-77
248
248
95
192
64
425
0
40
-77
39
65
39
96
160
22 224
369
273
168
200
175
165
148
163
167
312
311
508
?47
tea
261
286
285
310
274
288
266
316
297
299
281
311
127
27?
CL
893
1244
990
836
14?0
1185
1047
1561
1(134
1079
1088
1088
244
325
506
1217
1172
1534
1276
767
1146
1018
938
95
1
190
378
336
184
312
3?3
340
295
244
313
208
343
360
355
357
266
276
321
334
321
374
249
406
330
257
341
3I»7
264
S04 P04 N03
1540 2. HO 33.0
1236 3.60 192.0
1071 4.20 138.0
912 3.80 114.0
1299 5.20 156.0
1298 4.80 180.0
1134 4.50 171.0
2726 1.04 197.0
1349 4.30 124.0
1430 -.04 115.0
1422 5.00 103.0
1422 5.00 103.0
761 -.04 3.9
1278 .40 2.3
1854 .28 3.4
1188 1.50 15.8
1493 -.04 12.7
1701 -.04 64.0
1921 -.04 92.0
1633 3.30 56.0
1484 3.02 559.0
1167 6.60 60.0
1345 4.60 95.0
620 .74 6.4
401 30.00-100.0
451 18.50 1.6
409 23.80 12.1
391 25.50 .2
420,12.40 52.0
413 20.08 14.2
437 22.40 53.3
377 28.90 71.4
404 24.40 2.4
371 18.60 9.8
319 29.70 .7
366 21.50 4.2
542 15.50 13.6
435 17.50 9.3
560 22.40 6.6
544 26.20 4.2
483 23.00 3.8
506 19.70 2.5
477 17.80 1.9
412 18.70 .8
523 18.20 3.0
348 26.00 2.1
457 11.20 2.5
504 19.30 3,5
453 27.00 1.3
472 18.00 2.0
496 16.00 2.<)
475 29.01) 3.2
NA
911
830
68?
578
920
806
737
1920
708
1210
771
771
221
239
574
802
1355
1142
1433
627
796
690
654
98
215
291
245
160
220
242
250
228
193
220
204
236
267
247
292
257
250
271
256
245
282
209
285
270
?31
260
242
240
K
54
76
60
47
78
74
63
93
6
57
61
61
12
15
25
73
94
110
59
40
63
54
59
18
14
16
14
15
17
18
20
16
17
17
15
15
19
17
18
19
14
18
15
15
17
16
16
16
16
15
16
16
C*
?46
388
31?
281
463
391
370
378
378
235
396
396
134
269
229
342
260
443
297
404
446
397
403
167
113
125
124
105
127
1?5
125
101
112
112
89
115
145
131
136
108
108
130
127
110
127
95
131
130
108
119
119
109
MG
74
119
96
59
109
116
91
50
165
6
164
164
98
185
201
127
-0
101
4
114
105
72
127
68
63
73
68
58
71
65
70
58
60
63
58
59
72
65
70
66
60
68
65
58
69
53
63
64
51
62
58
58
NH4 F
8.4 2.0
1.9 3.4
2.2 3.0
1.3 2.2
1.4 2.8
.9 2.7
3.8 2.4
1.8 1.2
.7 3.0
.7 .7
.7 -.0
1.7 -.0
4.5 -99.0
4.5 -.0
,4 -99.0
2.1 3.7
3.6 -99.0
2.6 -99.0
4,8 -99.0
4.8 -99.0
4.8 -.0
4.8 -.0
4.8 -.0
4.8 -.0
.0 1.2
.0 .4
.0 .9
.0 .8
.0 .6
.0 .6
.0 .7
.0 .7
17,7 .7
17.3 .6
17.1 .8
23.4 .5
16.1 .6
22.3 .7
22.8 .8
23.2 .7
28.0 .7
26.0 .6
24.5 .5
33.0 .6
29.0 .5
28.0 .8
25.0 .5
27.0 .6
20.0 .9
29..0 .7
26.0 .6
22.1 .«
OS- SUM
3763
4135
3401
2871
4535
4112
3673
6929
3902
4133
4132
8392
1525
2413
3424
3981
4390
5117
5088
3668
4639
3489
3678
1157
1207
1489
1315
1037
1319
1302
1391
1256
1157
1296
1094
1335
1572
1437
1614
1455
1386
1515
1454
1356
1584
1182
1543
151?
1304
1472
1345
1351
-------
POIMT in^HTTFIER AND LOCATION
00
IVJ
«0 nA YR
11- (S-73
I7- 4-72
I- 5-73
:«- 4-73
4- 1-7^
•5- 3-73
5-11-73
7- 3-73
8- 1-7T
9- 4-7?
10- 3-73
11- 1-73
I?- 4-7*
I- 2-74
LH 38 BMI
2-28-70
^-11-70
5- 5-70
fi- 5-70
7- 8-70
8- 7-70
9-10-70
9-10-70 .
13-15-70
1-19-71
4-73-71
Nijwn
1793
1840
1864
1992
?010
1975
2095
2119
2173
2238
2275
2288
2301
2310
SEE"
12
23
54
86
120
150
172
173
326
355
459
TFMP
33.3
3D. 6
-99.0
21.1
17.8
24.4
26.7
28.9
29.4
28.3
27.8
-99-. 0
-99.0
18.3
PARCO
-99.9
22.0
22.2
28.1
23.9
28.3
30.0
30.0
-99.9
17.8
19.4
CONP
330R
3858
15*3
2382
3708
2200
3740
2617
2082
1862
2436
2100
2037
1946
RO
11000
8772
8092
6565
6371
6329
6353
8154
8154
7806
8409
PH
7.34
7.45
7.43
6.90
7.06
7.05
6.74
7.17
8.10
8.60
7.85
7.91
7.67
7.50
21S 63E
7.83
8.42
7.35
7.30
7.50
7.62
7.42
7.38
8.36
8.39
7.28
LH 39 GRAVEL PIT DRAIN 21S 6JE
•5-21-70
6- 6-70
7- 7-70
8- 7-71
9-13-70
9-13-70
12-15-70
1-19-71
6-11-71
r- 7-71
•1-33-71
13- 1-71
1- 3-72
2- 1-73
1- 3-72
4- 5-72
5- 2-7?
f>- 1-73
7-10-72
>)- 6-72
9- 7-73
10- 1-73
11- 6-72
17- 4-7?
96
89
115
153
220
221
327
356
516
617
777
929
1010
1160
1251
1339
1429
1443
7454
1600
1666
1682
1783
1B39
21.9
23.3
24.8
25.6
22.5
22.5
-99.9
18.9
22.0
-99.9
20.0
17.5
11.9
11.7
15.0
22.0
22.2
23.9'
39.5
28.3
Z2.Z
20. t)
15.6
5603
5473
5451
53*9
6063
7331
7361
5709
9382
8299
7572
7419
7932
8173
7896
8190
8326
8745
9454
9130
8384
X140
8532
861)5
7.75
7.70
7.75
7.94
7.83
7.80
7.39
7.42
7.75
7.85
7.75
7.40
7.58
7.52
7.69
7.35
7.55
7.16
7.77
7.72
7.61
7.45
7.54
7.71
HC07
275
305
219
329
303
289
199
311
136
143
122
140
127
112
CL
263
348
177
269
388
282
446
391
370
280
344
251
285
379
S04 P04 NOT
485 36.00 2.0
695 24.00 5.6
315 23.00 2.0
412 29.00 .4
604 20.00 .6
489 27.00 .0
546 19.00 1.2
513 22.00 .4
527 17.00 2.6
516 31.00 1.7
511 27.50 .9
483 29.00 1.6
480 31.00 2.4
569 23.00 99.0
NA
346
335
161
334
304
238
312
298
276
261
287
236
241
294
K
17
19
12
15
18
13
17
32
19
18
17
16
17
17
CA
lie
147
78
119
153
124
134
136
150
131
138
109
118
150
MG
55
81
42
58
78
58
75
65
58
54
61
58
61
71
NH4
28.0
39.0
14.0
31.0
23.0
29.0
33.0
30.0
25.0
24.0
24.0
24.0
24.0
24.0
F
.8
.8
1.2
-99.0
-99.0
•-99. 0
.5
-99.0
-99.0
-99.0
-.0
-.0
-.0
-.0
OS-SUM
1385
1825
933
1319
1738
1403
1682
1640
1513
1387
1471
1277
1322
1681
31 313 1
39
67
75
66
87
89
84
83
71
77
90
29 332
115
118
104
119
165
155
182
190
162
154
137
129
131,
13J
125
122
116
122
122
143
166
164
157
144
2760
2506
1903
1810
1740
1750
1581
1728
1460
1438
1567
5
1570
1430
1485
1565
1590
1650
1474.,
1319
1762
1907
1689
1748
1855
1878
1925
1981
1999
7144"
1999
2114
1983
1936
1949
1914
2725 -.10 123.6
1503 -.10 265.8
2504 -.10 194.9
2248 .10 203.8
2172 .45 161.7
2136 -.10 186.1
2169 -.10 150.6
1720 -.10 146.1
2441 -.10 150.0
2431 -.10 144.0
2405 .70 150.0
1737 .12 179.4
1788 -.10 181.6
1924 -.10 172.8
1607 -.10 201.6
1374 -.10 221.5
1855 -.10 199.2
1879 -.10 157.0
1875 -.10 146.5
1744 -.10 134.0
1588 -.10 129.0
1707 -.10 97.0
1785 -.ID 126.0
1830 -.10 92.0
1864 -.10 86.0
1882 -.10 76.0
1901- .04 78.0
1934 -.04 80.0
1918 -.04 96.0
1971 -.04 110.0
1895 -.04 93.0
1851 -.04 92.0
1765 -.04 96.0
1845 -.04 104.0
1830 -.04 60.0
1262
850
944
950
860
905
815
852
809
790
834
566
538
540
480
495
621
512
544
520
526
623
600
614
624
662
692
725
836
895
952
933
925
946
921
35
40
47
56
56
58
58
64
59
58
61
39
41
89
96
112
111
121
117
66
82
87
116
111
117
129
129
133
125
119
111
103
96
B9
91
815
750
766
694
562
775
740
723
704
751
733
725
736
650
700
724
735
695
634
837
812
707
792
796
790
779
771
793
813
811
740
736
702
742
742
489
340
356
360
344
320
315
305
298
305
320
300
296
316
300
300
295
285
292
351
336
307
322
328
333
332
326
3J7
317
299
283
251
253
255
259
.0
.0
.0
.0
.0
.0
.0
.0
.0
.1
.1
.0
.0
.0
.0
.0
.0
.0
.2
.2
.2
.2
.2
1.4
1.4
.2
.1
.1
.2
.2
.1
.1
.2
.3
.3
.4
.5
.5
.5
.4
.5
.5
.5
.4
.5
.5
.4
.4
.4
.5
.5
.5
.5
.6
.8
.7
.8
.6
.6
.7
.6
.7
.7
. .7
.8
.9
.9
.9
.9
.9
8230
6389
6752
6355
5939
6175
5870
5571
5956
5955
6116
5173
5069
5228
5008
4898
5543
5213
5012
5495
5457
5285
5553
5692
5759
5847
59J9
6039
6310
6365
6259
6032
5855
6009
5889
-------
00
POtNT IHFN
MO OA YR
1- 4-73
1-31-73
3- 4-73
4- 1-73
5- 2-73
•5-31-73
7- 2-73
8- 1-73
9- 5-73
10- 2-7*
12- 4-73
1- 2-74
3- 2-74
i»- 4-74
5- 8-74
6- 5-74
7- 2-74
B- 2-74
g_ it-jit
in- 3-74
11- 6-74
12- 4-74
2- 6-75
3- 7-75
4- 3-75
6- 3-75
7- 1-75
8- 5-75
9- 4-75
10- 7-75
11- 5-75
12- 3-75
12-30-75
2- 3-76
3- 4-76
4- 1-76
UW 30 PONf)
6- 5-70
7- 8-70
8- 7-70
9-10-70
9-10-70
12-15-70
1-19-71
4-22-71
6-11-71
7-73-71
S-30-71
11-10-71
I?- 1-71
I- 3-72
?- 1-7?
5- 2-77
T^FTER ANO LOCATION
NUMB
181.8
1898
1984
1965
1969
2108
2125
2164
2243
2271
2297
2314
2327
2333
2341
2351
2358
2364
2371
2377
2381
2386
2401
2407'
2412
2422
2428
2436
2439
2446
2450
2454
2460
2465
2469
2474
ADJ
91
123
155
162
163
328
357
436
512
632
704
820
92".
1007
11?7
1 4? 3
TFMP
-99. n
15.6
16.7
13.3
20.0
24.4
28.9
23.3
25.6
22.2
-99.0
11.1
-99.0
15.0
23.3
25.0
21.7
28.9
26.1
23.9
18.9
15.6
14.4
16.1
19.4
28.6
20.6
-99.0
21.7
20.6
20.0
19.4
16.1
18.0
16.0
23.0
LV HASH
22.5
25.3
23.6
22.8
22.8
-99.9
13.3
19.4
22.0
25.0
23.3
16.1
14.0
11.9
9.0
23.3
CON"
B6f)9
8124
9136
8236
8026
8320
7592
7077
6427
7500
8264
6231
8100
8284
8162
7277
7723
7956
7385
7582
8897
7517
7994
8054
8161
8749
8698
8508
8629
8354
7408
7668
8051
8029
8588
10011
P-H
7.5S
7.61
7.60
7.56
7.50
7.69
7.89
7.77
8.50
7.97
8.05
8.05
7,91
7.85
7.61
7.95
7.9*
7.74
8.05
8.85
7.48
7.39
7.80
7.20
7.52
5.90
5.70
6.13
7.25
6.26
7.29
7.49
7.61
7.25
7.85
6.60
21S 63E
5846
5579
5432
5573
7361
7571
7211
7388
K063
7439
8240
7250
6720
68?4
5> 891
6701
7.70
7.65
7.92
7.73
7.75
7.53
7.47
7.60
7.65
7.23
7.15
7.32
7.34
7.57
7.56
7.56
HC03
1-40
139
143
142
164
152
188
156
167
109
154
151
158
165
188
201
106
180
198
195
175
167
160
158
145
187
193
188
210
181
198
192
192
162
158
140
28 142
230
234
211
239
244
243
253
242
251
260
257
253
260
256
256
256
Ct
1924
1913
1972
1932
1853
1875
1692
1650
1534
1490
1693
1693
1724
1799
1791
1758
1655
1699
1585
1643
1684
1643
1683
1757
1925
1917
1897
2189
1764
1841
1737
1891
2838
2885
2312
2846
1
1383
1470
1436
1445
1550
1470
1380
1361
1367
1399
1370
1300
1261
1252
1236
1262
504 P04 N03
1909 -.04 116.0
1853 -.04 127.0
1817 -.04 144.0
1911 -.04 130.0
1738 -.04 142.0
1979 -.04 157.8
1619 -.04 131.8
1784 -.04 106.0
1795 -.04 99.0
1876 .17 126.0
1828 -.04 104.0
1928 -.84 102.0
1814 .06 129.0
1892 .06 136.8
1863 .86 129.8
1789 -.84 114.8
1735 -.04 139.0
1909 .18 1.3
18*7 -.82 144.0
1835 .18 148.0
1849 .18 153.0
1783 .10 161.0
1843 .10 141.0
1788 .06 163.0
1775 .11 175.0
1835 .14 165.0
1875 .17 135.0
1711-99.80 175.8
1537-99.00 173.0
1755-99.08 244.0
1471 .06 148.8
1419 .07 151.0
1434 .04 151.8
1379 .88 147.0
1474 .01 123.0
1518 .12 143.0
1998 -.18 59.9
1873 .20 64.2
1677 .12 119.6
1736 .15 75.3
2165 .12 57.3
2185 -.10 57.0
2176 -.10 63.6
2181 .12 64.5
2129 .14 62,4
2215 -.10 59.6
2106 .20 61.0
2110 -.10 55.0
2092 -.10 73.0
2072 -.10 59.0
2067 -.10 59.0
2067 .12 54.0
NA
894
^08
898
896
895
891
812
847
853
812
852
878
831
878
888
908
865
850
830
888
915
794
835
850
904
284
922
868
815
859
674
680
670
656
758
820
750
728
585
615
740
747
768
/20
747
779
737
753
741
675
682
715
K
94
91
89
95
66
93
79
76
81
55
58
60
65
68
63
68
65
65
58
55
55
53
47
6
61
64
62
178
170
64
46
44
43
48
41
45
38
85
90
73
89
85
81
77
76
fll
83
80
85
78
77
79
CA
717
708
742
752
717
691
636
604
636
614
681
675
699
ero
64)
657
574
665
651
637
653
592
679
627
634
79*
737
670
595
657
453
475
463
662
740
900
558
524
602
630
635
640
594
638
6T2
635
652
626
630
647
602
600
MG
258
258
258
260
236
257
217
277
206
221
233
249
247
254
243
234
221
239
231
233
243
237
237
249
260
520
275
266
250
266
218
298
268
334
381
474
315
318
288
288
304
288
295
279
292
292
287
290
271
260
258
265
NH4
2.8
2.4
.1
.1
.2
.3
.4
.4
.4
.4
.4
.4
.4
.4
.4
.4
.4
.4
.4
.4
.4
.4
.4
.4
.4
.4
.4
.4
.4
.4
.4
.4
.4
.4
.4
.4
.0
.0
.0
.0
.0
.0
.0
.0
.4
.0
.0
.0
.0
.0
.0
.0
F
.9
-99.0
-99.0
-99.0
-99.0
.9
-99.0
-99.0
-99.0
-.0
-.0
-.0
-.0
-.0
-.8
-.0
-.8
-.9
-.0
-.8
-.8
-.0
-.0
-.0
-.0
-.0
-.0
-.0
-.0
-.0
-.0
-.0
-.0
-.0
-.0
-.0
1.0
1.1
1.1
1.1
1.1
1.1
1.1
1.0
1.1
1.1
1.1
1.0
1.0
1.0
.8
1.0
OS-SUM
5985
5930
5991
6046
5728
6019
5279
5421
5287
5248
5525
5651
5587
5778
5713
5620
5326
5518
5484
5527
5559
5345
5544
5514
5805
5673
5999
6070
5408
5776
4841
5053
5162
5383
5899
6808
5207
5170
4901
4982
5662
5593
5483
5441
5430
5590
5424
5340
5282
5170
5107
5169
-------
POINT IIFNTTFtE" «ND LOCATION
00
10 nft Y" MI(MR TEMP CON"
6- 1-72 14(»0 23.3
7-10-72 152* ?7.5
1- 7-72 1596 25.6
1- 4-75 181.7 -99.0
LW M CHARLESTON DITCH
«- 6-70 142 ?6.8
9-11-70 216 28.9
9-11-70 217 28.9
12-16-70 329 -99.9
4-23-71 4&5 21.7
fi-14-71 537 25. 0
7-26-71 6*8 27.2
S-31-71 735 27.0
12- 2-71 918 6.0
t- 3-7? 1858 16.7
Z- 1-72 1175 19.0
6- 1-72 1454 ?4.4
7-10-72 1581, 30.0
11- 7-72 1806 24.4
1?- ",-72 18J4 21.1
I- 5-73 1871 -99.0
3- 4-73 1997 18.9
t.- 1-73 ?015 17.8
5- 2-73 1980 22. «
5-30-73 2092 25.6
7- 2-7^ 2115 27.8
»- 1-73 2177 27.8
LM 32 GRAVEL FIT SEEP
9-10-70 164 22.8
9-10-7!) 165 22.8
1?-15-70 325 -99.9
1-19-71 354 20.6
i»-?2-71 4^9 19. i»
6-11-71 515 21.0
7-23-71 635 22.2
8-^0-71 707 21.7
in- 1-71 787 21.1
11-10-71 827 22.2
1?- 1-71 9(14 17.0
1- 3-72 1013 19.0
2- 1-72 1161 17.0
3- 2-72 1250 21.7
4- 5-72 1340 22.0
"5- 2-7? 1430 22.2
6- 1-7? 1444 23.9
7-10-7? 1526 ??.0
1- 6-7? 1599 23.3
9- 7-7? 1665 20.0
in- 1-7? 1681 23.3
69B8
7513
74*4
7150
221.5
2077
?208
2650
2729
2851
2707
2618
2733
2688
2658
2*72
2653
26?1
26??
2711
2911
2900
283?
Z8>.0
271.7
2262
5430
7182
6955
6625
7«.95
86110
82?0
7562
77B1
7849
7764
7583
7913
7851.
8087
870?
9501
9?06
8909
7761
-0
PH HC03
7.23
7.62
7.61
7.1.7
20S 61E
8.1.5
8.09
7.97
8.21
7.78
7.90
7.65
8.15
8.03
8.02
8.01
7.78
7.89
8.99
7.54
7.70
7.71
8.12
7.81
7.93
7.79
8.10
21S 63E
7.62
7.63
7.20
7.3?
7.22
7.25
7.37
7.42
7.78
7.31
7.43
7.1.9
7.53
7.61
7.13
9.1.0
7.71.
7.56
7.62
7.55
7.28
260
21.8
27<>
261
CL
1300
131.9
1398
1329
S04
?l?fl
?210
2088
2117
P04 N03
.44 50.0
.20 51.3
-.08 44.9
.10 38.0
NA
733
733
708
691
K
86
82
89
82
Cft
fi?0
653
6*6
6?4
MG NH4 F OS-SUH
274
275
283
275
.4 1.1
.1 1.1
.1 1.1
.2 30.0
5313
5477
5382
5315
36 31.3 1
319
311
317
336
174
337
332
321
329
317
299
32?
319
356
1.19
350
339
336
321
333
259
301.
32 231.
95
98
17?
161.
219
213
173
157
117
151
109
110
11)
131.
127
136
11.2
181
175
210
212
103
90
75
105
119
115
116
83
106
110
117
113
116
181.
253
115
1Z5
133
136
92
121
111
1
1553
1630
1263
1268
17?9
1982
2007
1563
1775
1685
1759
1709
1751
1811
1971
2058
2398
2096
19*3
1695
1685
1198
91.0
1006
1271
1277
121.5
1275
115?
1251
1255
1212
1165
1185
718
828
1203
1287
1380
1352
1338
1262
1088
1591
203?
1944
1938
1555
f.68
1539
11.23
1801
1851
1865
1935
1866
1922
1971
1959
1723
1823
1870
1805
1671
-*10 3.2
.93 5.3
.83 .0
-.10 130,5
-.10 108.5
-.10 106.8
-.10 82.0
-.10 124.0
-.10 86.0
.20 157.0
-.10 98.0
-.10 101.0
-.10 56.0
-.04 63.0
-.01, 84.0
-.04 122.0
-.04 108.5
.10 101.0
-.04 102.0
-.04 116.0
128
114
123
136
114
148
148
120
t41
138
137
129
132
437
339
133
147
166
150
145
147
154
514
649
480
510
446
547
666
691
538
694
506
593
522
716
862
950
1245
1160
1155
1065
1025
28
25
27
36
35
32
32
33
33
27
28
25
28
28
20
28
29
32
30
33
43
30
74
81
56
57
34
36
38
37
52
34
43
38
43
38
46
37
53
34
32
31
28
180
175
182
214
21?
207
205
1<»1
217
210
218
202
196
75
96
200
212
?23
210
201
208
198
790
796
752
673
795
817
783
589
868
760
875
832
836
8?1
777
819
762
704
669
610
590
202
173
163
194
218
215
216
199
210
210
195
195
189
71
121
205
217
230
225
228
206
193
275
266
268
397
338
351
328
237
331
294
320
299
317
294
274
263
235
203
196
170
1
..0 .4
.0 .3
.0 .3
.0 .3
.0 .4
.0 .3
.0 .4
.0 .3
.0 .3
.0 .3
.0 .3
.0 .3
.1 .3
.2-100.0
.2-100.0
.2 2.0
.2 -99.0
.2 -99.0
.3 -99.0
.1 .3
.1 -99.0
.1 -99.0
.0 .5
.0 ,5
.0 .5
.1 .6
.1 .9
.1 .9
.1 .8
.1 1.0
.9 .5
.9 .9
.9 .5
.4 .6
.4 .5
.1 .8
.1 .9
.1 .8
.2 1.0
.2 1.2
.1 1.1
.1 1.3
.1 1.3
2000
1677
1738
2128
2066
2134
2160
1944
2130
2113
2059
1992
2008
1680
1664
2058
2192
2337
2268
2208
2120
1929
5026
5697
5008
4978
5136
5415
5553
4700
5548
5480
5580
5559
5492
5725
6026
6238
6609
6219
6053
5583
5221
-------
00
POINT in*
MO DA YR
NTIFtER AND LOCATION
NUMB
TEMP
COND
L.H 33 TRin TO OUCK CK
9-11-70
9-11-7(1
4-'3-71
7-Z6-71
•^-30-71
11-10-71
1?- ?-71
3- 2-7?
'•»- 5-7?
5- 4-72
7-10-7?
8- 6-7?
1- 4-73
1-16-73
LM 34 LV
3-31-70
5- 4-70
6- 4-70
7- 7-70
8- 6-70
9-11-70
9-11-70
12-15-70
1-19-71
3-30-71
4-72-71
ft-ll-71
7- 7-71
7- 7-71
•J-30-71
10- 1-71
lt-tfl-71
1?- 1-71
I- 3-72
2- 1-72
.3- 2-7?
it- 5-72
5- 4-72
ft- 1-72
7-10-7?
1- 6-7?
9- 6-7?
10- 1-72
1?- 4-7?
1- 5-73
3- I.-73
4- 1-73
•>- 2-73
5-30-73
7- 2-73
19?
193
46?
647
714
836
915
126?
-0
1386
1575
1628
1857
1881
18.3
18.3
14.4
23,3
21.0
12.?
8.0
-99.0
19.0
16.5
23.3
25.6
-99.0
9.4
5598
6650
6896
7870
7765
7040
6944
6843
6644
7097
8216
8107
7160
7097
STP OUTFALt
26
38
82
110
146
210
211
331
360
402
449
524
613
614
721
804
838
900
1038
1172
1?58
1346
1380
1452
1533
1625
1644
1696
1B?7
1863
1993
2013
1976
2073
2116
20.5
22.4
?8.9
27.8
30.0
29.4
29.4
-99.9
20.6
22.0
23.3
28.0
-99.0
-99.9
31.1
25.6
23.3
21.0
7.2
19,0
19.4
24.4
24.5
27.2
-99.0
30.6
27.2
28.3
18.9
-99.0
21.1
17.8
25.6
28.3
30.6
1513
1028
1403
1126
10?3
1449
1417
1476
1510
1450
1521
1615
1406
1635
1825
1644
1681
179?
17?4
1845
1484
1607
1521
1798
1604
1886
1^22
1628
1830
2618
2019
2021
1889
15f>4
1888
PH
215 52E
7.34
7.40
7.32
7.30
7.50
7.50
7.49
7.66
7.20
7.44
7.63
7.56
7.52
7.56
215 62E
7.30
6.98
6.80
7.00
7.29
7.02
7.29
7«46
7.31
7.26
7.23
7.25
7.35
7.55
7.42
7.15
7.26
7.42
7.51
7.41
7.40
7.16
7.44
7.36
7.23
7.26
7.42
7.21
7.32
7.35
7.22
7.25
7.22
6.96
7.53
HC03
22 442
257
241
232
284
266
229
?32
233
229
250
264
267
231
228
10 344
31?
263
224
194
117
180
171
305
106
258
301
264
245
240
254
289
277
270
240
293
244
308
247
229
276
164
269
270
253
?43
305
259
288
19?
330
CL
1
1014
1090
1002
11? 3T
1008
959
991
1012
981
1019
1126
1096
962
976
1
180
116
205
129
114
235
239
188
214
177
197
232
169
202
235
228
229
260
259
265
206
254
211
276
194
281
191
213
236
383
254
301
239
227
290
504 P04
2335 .38
2655 .44
2828 .20
3210 .12
3000 -.10
2644 .14
2765 -.10
?S8ft -.10
2837 2.30
?947 .10
3405 .18
3341 .12
?959 .20
2963. .10
HO 3
3.1
3.4
25.6
19.6
19.1
33.0
30.0
32.0
34.0
30.0
36.5
34.0
40.0
37.5
240 25.20-100.0
255 35.70
153 24.50
160 41.50
150 13.90
157 17.95
198 20.40
176 29.70
187 51.60
222 28.00
171 31.00
177 21.10
195 28.00
203 24.00
2?8 21.40
227 26.20
226 21.00
252 16^20
281 15.70
247 16.70
253 23.00
200 18.80
237 21.00
309 15.30
250 26.00
303 33.00
287 18.00
281 32.00
330 20.00
526 16.20
289 24.00
367 14.50
298 25.00
249 19. Ofl
279 15.30
27.5
6.6
1.1
48.5
35.4
67.1
5.0
4.4
16.8
5.0
11.9
9.6
14.5
10.4
4.5
2.7
3.3
3.4
5.2
8.4
8.4
6.0
7.0
6.9
9.6
-.0
2.6
2.2
.9
2.2
3.6
2.4
5.2
.1
NA
538
596
650
833
768
695
695
709
706
742
844
869
709
730
145
108
163
121
83
163
165
183
157
146
199
164
138
157
178
188
185
197
187
185
156
182
165
208
169
203
169
191
196
277
207
?18
197
157
199
K
61
73
46
42
58
47
51
55
50
50
46
43
53
54
12
13
13
12
13
14
11
13
16
16
15
13
14
14
13
14
12
14
12
14
13
14
11
12
13
13
13
13
13
16
13
13
10
13
28
CA
640
656
593
654
613
586
575
573
583
620
691
645
625
581
80
62
57
57
64
72
76
61
72
76
65
75
70
77
72
75
70
85
89
83
76
72
74
97
72
92
87
80
88
13?
81
99
90
73
91
HG NH4 F
350 0 1.8
356 0 1.9
368 0 1.6
418 0 1.7
406 0 1.4
362 0 1.4
371 0 1.5
373 0 1.6
363 1 1.7
384 1.6
426 1.7
421 1.7
365 1.7
373 1.8
53 .0 1.1
42 .0 .4
44 .0 1.0
37 .0 1.1
42 .0 .7
42 . 0 . 7
45 .0 .8
38 .0 1.3
40 20.7 1.0
44 17.2 1.1
40 17.2 1.2
43 14.8 .9
39 10.4 1.0
42 11.1 1.1
42 18.9 1.0
39 21.9 1.0
41 29.0 1.0
44 23.0 .8
45 18.4 .4
46 22.0 1.1
44 14.0 1.6
45 26.0 1.3
44 14.0 1.1
48 12.0 1.1
36 17.0 2.1
47 17.0 1.5
45 17.0 .7
37 19.8 1.7
47 25.0 .5
70 19.0 .6
41 31.0 -99.0
55 17.0 -99.0
44 27.0 -99.0
48 18.0 1.2
49 22.0 -99.0
OS-SUN
5070
5550
5629
6441
5996
5441
5594
5756
5671
5917
6706
6582
5828
5829
889
' 789
777
655
586
825
905
845
816
871
889
882
795
864
945
966
952
1028
1028
1029
915
974
905
1098
92?
1081
956
1004
1082
1560
1093
1216
1074
907
1136
-------
POINT lOFNTIFIE* AND LOCATION
MO OA YR
9- t-71
9- 4-73
10- 3-73
It- 1-73
1?- 4-73
t- 2-74
LH 35 BMI
2-28-70
^-31-70
5- 4-70
6- 5-70
NUMP
2174
2235
2274
2280
2300
2*11
NO. 1
10
19
39
74
TEMP
31.1
30.0
26.7
-99.0
-99.0
15.0
(DISC.
-99.9
24.0
29.7
35.8
CfJNn
1682
14*1
1776
1299
1455
1861
PH
7,85
7.28
7.87
8.09
7.66
7,63
> 22S 62E
14300
24821
8271
28105
3.05
8.21
3.39
6.90
HC03
154
163
130
118
121
103
02 14
-77
42
-77
43
CL
290
2? 8
302
211
234
289
4,1
3160
7550
2305
7680
•504 P04 NO*
287 17.00 7.2
267 71.00 3.fl
274 19.00 8.0
277 23.00 3.7
311 28.00 3.9
376 14.30 5*0
761 -.00 79*7
2355 <-.10 443.0
852 -.10 252. 5
1515 -.10 528.9
NA
20S
187
204
182
211
202
1375
3600
980
4050
K
14
13
14
13
13
12
266
33
15
39
CA
109
94
101
76
80
104
426
1115
320
1010
MG
46
39
44
39
41
49
375
415
340
440
NH4
17.0
20.0
20.0
20.0
20.0
20.0
.0
.0
.0
.0
F
-99.0
-99.0
-.0
-.0
-.0
-.0
.6
1.4
.7
1.4
OS- SUM
1071
iom
1050
903
1001
1122
6444
15533
5065
15286
LH 16 OSH GULF RO 21S 63E 1ft «»12 1
2-28-70 7 -99.9 337 6.33 9 77
2 .01 12.4
51
153
LH 37 OSH HAVERS-KO 215 63E 14 412 2
2-2*-70 8 -99.9 805 6.61 7 222
1 .64 13.7
125
12
.6
.1
408
LW 38 OSH AEROJECT RO ?1S 63E 14 412 3
2-28-70 9 -99.9 6410 6,88 7 205
3 .01 14.5
12
.1
GO
LH .19 GRAVEL PIT
6- 3-70 76 23.6
6- 5-70 77 29.3
9-11-70 194 26.4
9-11-70 195 26.4
LH 41 LAS
1-19-71
3-11-71
3-30-71
3-30-71
4-22-71
6-11-71
10- 1-71
11-10-71
1- 3-72
2- 1-72
3- 2-72
4- 5-72
22S 6€E
21982 6.80
26195 7.15
17171 7.33
17966 7.41
VEGAS HASH 9 21S 63E
361
376
406
412
443
518
799
825
1035
1164
3664
1341
LH 42 STAOFFER
1-19-71
4-23-71
6-11-71
8-10-71
17- 1-71
762
456
533
712
9011
13.9
9.5
14.4
14.4
14.4
18.5
13.9
10.0
6.9
?.B
9.4
19.0
EFF4. 3
21.1
^7.2
37.0
-"99.9
22.5
4015
3969
3920
3850
3391
39,19
3856
4098
3130
3472
3664
317B
7.54
7.59
7.76
7.81
7.75
7.80
7.75
7.61
7.31
7.66
7.88
7.48
22S-6HE
2760
*85 H3
45867
627<»4
*19flO
1.29
8.23
4.30
4.55
4.29
02 432 1
110 5700
111 6800
95 5499
94 5761
1380 .32
2000 .19
1667 .23
1975 .21
-.4
-.4
-.5
-.9
3520
4540
3612
4060
52
59
60
66
478
532
500
485
210
261
150
154
.0
.0
.0
.0
4.2
4.6
3.0
3.2
11399
14251
11538
12551
30 431 1
227
258
249
250
?45
300
253
214
215
191
234
246
651
646
596
5*1
487
550
476
622
448
438
526
483
1088 19.60
1071 19.60
1009 19.00
993 18.20
«67 20.90
920 23.20
878 18.90
1079 16.00
851 19,60
974 17.60
112IJ 19.30
1021 21.00
39.2
39.2
23.8
24.2
32.3
6.0
22.0
30.0
40.0
46,0
23.0
17.4
508
495
460
460
387
427
413
496
347
374
453
410
32
32
29
29
25
24
26
33
27
28
29
28
298
297
254
257
222
241
210
273
217
217
245
23J
119
119
105
113
99
105
92
116
95
107
118
110
.1
.1
.1
.7
.1
7.1
1.4
2.3
4.0
4<1
.2
.5
1.3
1.5
1.4
1.4
1.3
1.4
1.3
J..O
i.o
i.i
1.2
1.2
2868
2847
2620
2600
2262
2452
2263
2774
2155
2301
2657
2446
12 323 1
113
5*63
-77
-77
-77
506
28194
15646
19150
30186
554 . 36
1161 -.10
990 -.IT)
79H -.10
22M -.10
3,€
3.1
6-1
13.0
2.1
513
20500
HI 5 60
13635
22240
5
8
5
8
9
61
6
34
^51
^43
74
5
ID
19
11
.0
.0
.D
.0
.0
.3
.3
.1
1.7
.1
1729
52760
27251
33676
54760
-------
00
-J
POINT IOFNTIFTER 8MO
MO IB YR
t- ^-72
2- 2-7?
X- 2-72
5- 4-72
7-10-7?
S- 7-7?
1- 5-73
MUMP TEHP
1067 21.9
1195 26.0
1270 -99.0
1395 30.0
157? 30.0
1638 29.lt
I860 -99.0
LH 43 STflUFFER EFFL 6
1-19-71
4-23-71
6-11-71
8-30-71
9-Z3-71
11-11-71
1?- 1-71
?- 2-72
*- 2-72
5- 4-72
6- 1-7?
9- 7-72
1- 5-73
361. 41.7
., It55 22.2
53* 37.0
715 25.6
784 11.1
81lt 31.1
907 26.0
1196 22.0
1271 IB. 9
1396 23.0
11.66 30.0
1639 33.3
1661 -99.0
LH lilt STSUFFER EFFt 2
4-23-71
6-11-71
1-30-71
"-23-71
11-11-71
I?- 1-71
1- 3-72
LM 1.5 LflS
t-11-71
3-TO-71
3-10-71
4-22-71
6-11-71
10- 1-71
11-10-71
1- 3-72
?- 1-72
3- 2-72
it- 5-7?
i|57 23.9
535 35.0
713 32.2
783 31.0
613 42.2
909 37.0
1068 19.1
VF.GRS HASH
377 11.0
-------
POINT rOFHTIFTER AND LOCATION
•«0 1* Y<* M)»in TEMP CONn PH
HC03
CL
PO* NOT
NA
tie
NH*
F OS-SUM
00
00
LH *8 BMI
3-11-71
3-7D-71
3-30-71
6-11-71
7- 7-71
7-?6-71
8-31-71
9-28-71
11-11-71
12- 1-71
1- 3-72
2- 2-72
3-10-72
5- *-72
6- 1-72
7-10-72
8- 6-72
10- 1-72
11- 8-72
12- *-77
t- 5-73
2- 1-73
3- (,-73
ft- 1-73
5- 3-73
5-51-73
7- 2-73
9- 1-73
9- 5-73
11- 2-73
11- 1-73
I?- *-73
1- 2-7*
LM *9 BMI
3-11-71
5-30-71
3-^0-71
- 2-7?
3-10-72
•>- k-7?.
f>- 1-7?
7-10-7?
PONO
37«
*08
*1*
570
618
641
726
791
812
90?
1075
1190
1275
13R9
1**6
1565
1631
1700
1822
1831
1850
1918
1986
2006
201(1
2106
2127
7166
2205
2269
2286
229 it
2317
PONO
379
«t09
*15
539
619
6*2
727
792
811
903
1076
1191
1276
1390
1*1.7
1566
SEEP 2
lit. 5
15.0
15.0
-99.0
-99.9
22.2
27.0
18.3
15.0
16.0
11.9
11.0
-99.0
19.5
21.7
26.1
27.2
21.1
16.7
15.0
-99.0
12.8
15.6
15.6
25.0
22.8
28.9
2*.*
25.0
22.2
-99.0
-99.0
12.2
SEEP 3
15.0
17.2
16.1
21.5
-99.9
23.3
21.0
18.3
15.6
16.0
1*.0
13.0
-99.0
19.0
21.1
21.7
21S 63E
10750
10889
10889
1171lt
11529
11178
1161.7
10959
11206
11797
11595
11 51 It
10707
11*63
12
269
259
261.
226
280
262
21.7
2*3
235
2*0
7*6
259
265
261
269
7*37
7359
7376
7*3*
7*08
238*
2*70
2*5*
2*16
2*86
252*
2*52
2*85
7*77
2*06
.2*06
21*1
2189
2087
2079
207*
21*6
2136
2085
1965
1999
2018
70*3
7136
2105
2167
221?
.10
.2*
.26
.26
.26
.2*
.30
.31
.26
.30
.2*
.10
.25
.3?
'.32
.36
-.1
.2
.1
-.1
.1
-•1
-.1
-.1
.2
.2
1.1
1.6
3.7
2.8
-.1
-.1
1880
1890
1900
1815
176*
19*5
1931
1951
1855
1890
1910
1936
19*5
1915
1910
1861
36
50
*7
52
55
53
52
51
56
58
*3
57
56
5*
5*
5*
600
520
510
507
515
*76
*96
*91
*76
*5*
*65
*69
*72
(.80
*77
*S5
177
131
125
13*
138
1*2
135
176
118
177
177
13*
12*
179
179
13*
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.5
.2
.2
.1
3.5
3.1
3.3
3.3
3.0
3.0
3.2
3.5
3.2
3.0
3.0
3.2
3.*
3.3
3.5
3.*
73**
7275
7176
715*
7069
7287
7352
728*
7009
7133
7210
7216
73*9
72*7
7275
7295
-------
00
ID
POINT IDENTIFIER AND
MO HA YR
8- 6-72
10- 1-72
11- 8-72
'1- 4-73
?- 1-73
3- 4-73
It- 1-73
5- 3-73
5-U-73
7- 2-73
8- 1-73
9- 5-73
10- 2-7^
It- 1-73
1?- <4-73
1- 2-7«t
LW 50 E.
U-73-71
6-14-71
8-M-71
9-?7-71
11-11-71
1?- 2-71
t- 3-72
It- 6-72
6- 1-72
7-10-72
9- 6-72
11- 7-72
12- - 1-7?
11- 6-72
1-31-73
3- 4-7?
It- 1-73
5- 3-73
3- 2-7lt
It- it-7U
•5- S-74
t>- 5-7it
8- 2-7t8 23.3
1419 27.8
1453 31.1
1793 13.3
1903 11.1
1995 18.9
2011 l«t.«t
1978 30.0
2325 2?. 2
2331 10.0
233* 23.9
2355 32.2
2366 35.6
2378 26.7
i»222
t»0?9
It002
3650
3832
It 156
4168
4168
4457
It0>t6
45«5B
It 093
It072
3958
3958
3700
2911
3759
7.771,
PM
7.6lt
'.25
7.27
7.29
7.32
7.61
7. 46
7.1t6
7.32
7.25
8.15
8.19
8.13
8.34
7.95
8.22
20S 62E
7.49
9.60
7.77
7.75
8.95
7.98
8.30
8.53
7.41
7.16
7.40
7.38
7.37
7.90
21S 62E
7.86
7.99
7.85
8.14
8.03
7.38
7.97
7.59
7.98
8.25
8.01
7.87
7.98
7.96
7.96
8.45
7.62
8.29
7.55
HC03
263
266
268
270
271
270
276
2»5
325
408
313
303
229
277
261
130
30 243
208
-77
158
149
317
382
214
202
252
90
200
261
222
273
10 233
194
259
252
239
213
164
123
- 304
-0
187
154
236
144
173
?6B
228
184
195
141
CL
?404
2439
2447
2341
2236
2271
2211
2236
2191
2307
2167
2206
2483
?111
2149
2138
1
89
96
127
144
71
92
77
186
109
196
15
193
168
412
1
380
372
356
307
347
371
431
365
426
390
386
351
375
345
326
345
434
348
97
S04
2221
2145
2164
2208
2214
Z167
2186
2175
2380
2521
2110
2094
2101
2102
2077
2133
538
265
442
775
418
464
409
616
466
469
117
582
474
2182
2008
1929
1808
1645
1858
1904
1951
2040
2074
2014
1950
1908
1860
1840
1776
1627
964
1640
1070
P04
.38
.26
.26
.30
.22
.28
.28
.44
2.60
2.60
1.00
.30
.62
.73
1.07
-.07
7.00
.12
1.96
.99
2.30
1.70
.96
2.50
2.00
.50
2.10
4.90
8.10
-.04
.46
-.10
-.10
-.10
-.10
.38
.22
.90
-.04
-.04
-.04
-.04
-.04
.04
.06
1.18
12.00
.38
-.02
NO 3
.1
-.1
.2
-.1
.4
-.1
-.1
.2
2.1
.7
-.1
-.1
-.5
.2
.1
-.1
.3
.2
.2
.4
.3
.3
.2
.7
7.4
.4
3.6
.5
.4
2.1
.1
.5
3.1
4.0
1.5
-.1
4.7
.4
.1
1.8
-.1
.7
,2
.7
.7
.2
12.2
-.5
7.9
NA
1985
2010
1899
1904
1857
1930
1935
1813
1575
1715
1700
1695
1707
1687
1666
1692
104
64
137
173
73
103
91
178
112
158
14
199
169
310
288
267
254
217
235
265
304
276
302
283
273
264
245
261
262
286
412
265
116
K
53
56
53
50
48
50
51
49
55
99
63
57
48
45
44
45
31
13
IS
44
13
20
10
26
16
25
6
29
16
23
21
19
18
18
19
20
22
26
21
22
21
19
17
18
17
16
37
21
35
CA
480
482
475
483
454
446
441
4*6
538
587
455
462
444
443
444
430
122
67
126
154
117
120
104
160
149
115
85
147
133
386
384
380
348
331
337
347
331
424
357
378
345
372
333
334
336
316
180
300
302
MG
134
134
139
136
135
128
130
141
232
247
150
169
150
143
153
147
84
31
38
90
88
97
74
65
53
41
19
67
50
321
305
292
271
247
272
?83
287
2*6
314
299
295
279
265
254
252
?33
98
233
71
NH4
.2
.3
.4
.2
.3
..2
.2
.6
3.2
.7
.7
.7
.7
.7
.7
.7
.0
.0
.0
.0
.0
.0
.0
.0
.0
.2
.5
.5
2.3
.2
.0
.0
.0
.0
.0
.0
.0
.4
.2
.3
.2
.2
.1
.1
.1
.1
.1
.1
.1
F
3.3
3.5
3.6
3.7
-99.0
-99.0
-99.0
-99.0
1.8
-99.0
-99.0
-99.0
-.0
-.0
-.0
-.0
.5
.4
.5
.5
.4
.4
.4
.6
.5
.8
.3
.5
.6
.7
.6
.5
.5
.6
.6
.5
.6
.6
.6
-99.0
-.0
-.0
-99.0
-.0
-.0
-.0
-.0
-.0
-.0
OS-SUM
7411
7401
7313
7259
7078
7125
7090
6991
7141
7680
6801
6833
7'047
6669
6663
6649
1078
537
966
1454
938
1086
872
1333
1039
1050
362
1352
1131
3772
3483
3388
3177
2887
3174
3271
3392
3569
3495
3480
3346
3310
3166
3138
3102
2937
2239
2903
1768
-------
pntMT
»NT LOCAHnN
MQ HA Y°
11- 6-74
17- 1»-7I,
?- 6-75
3- 7-75
4- 3-75
6- 3-75
7- 1-75
NIIMfJ TEMP
?384 11.1
2391 in. 6
2402 11.1
2408 20. n
2414 19.4
2421 24.4
2427 26.7
conn
31Fi2
2582
3698
3523
3558
3561
3917
PH HC07
7.99 283
7.26 21?
8.24 224
7.84 231
7.51 230
6.70 204
6.20 176
CL
307
214
298
285
303
303
350
•504 P(
1548
1079 -
1669
1599
1669
1436 1
1675
34 N03
02 4.0
03 8.0
04 3.5
18 .1
27 3.1
78 -.1
43 -.5
NA
256
167
257
273
231
256
311
K
19
22
19
20
1ft
18
21
CA
305
229
J04
268
423
271
294
MG NHI.
236
152
223
223
216
206
225
F DS-SUM
-.0 2814
-.0 1975
-.0 2884
-.0 2782
-.0 2977
-.0 2592
1 -.0 2963
LW 52 LVBH USED HATER 21- 1-7?
5- 3-72
529
911
1051
1183
1408
26.0
6.0
15.6
6.0
2*.. 4
3026
?5?0
2576
2502
2911
LW 55 STBUFF CUT FLUME
6-11-71
7-26-71
1-30-71
9-23-71
11-11-71
12- 1-71
1- 3-72
2- 2-72
3- 2-72
It- 6-72
5- 4-72
6- 1-72
7-10-72
9- 7-72
9- 7-72
10- 1-72
1- 5-73
532
638
711
785
815
906
1066
1193
-0
1352
1J91
1<»65
1571
1640
1663
1679
1862
30.0
23.9
26.7
29.0
30.0
29.0
22.0
23.0
-99.0
2ii.li
29.0
28.3
26.1
28.9
30.0
28.3
-99.0
18936
1.311
12621
9151.
94?8
20391.
5767
8407
8843
60911
18153
20842
3069
5187
1*501
3872
12416
s.oo
8.02
8.04
8.01
8.13
22S 62E
12.55
8. 74
1.85
3.90
2.27
7.28
11.25
10.75
2.20
1.36
2.31
1.32
2.90
3.67
12,51
11.80
13.35
164
150
148
154
157
503
426
442
418
517
660
600
588
568
70Q
.14
-.10
-ilO
-.10
-.04
-.1
1.0
2.2
2.9
-.1
279
24?
240
233
303
24
18
17
17
25
149
139
140
129
144
133
114
113
111
130
.0
.0
.0
.0
.0
1.3
1.0
1.0
1.0
1.3
1828
1618
1616
1556
1897
12 324 1
-77
174
-77
-77
-77
255
-77
>.9
-77
-77
-77
-77
-77
•r77
0
0
0
2393
961
849
1235
1664
6663
1365
2533
702
20960
4774
947
468
1400
2237
588
15815
798
512
3228
3280
1114
846
434
362
2732
2127
2254
3509
6'29
431
508
320
2267
.24
.24
.58
.39
3.00
.20
-.10
-.10
2.10
17.50
1.40
28.00
-.04
.30
.08
-.04
-.04
7.2
3.7
6.6
8.3
39.0
1.2
16.0
4.3
12.9
10.7
4.6
'11.2
9.5
'3.5
5.2
4.7
27.5
2932
849
1312
2003
1307
4430
1220
1823
1099
14365
3670
402
302
944
2595
699
22100
7
49
11
8
7
9
6
6
12
14
8
5
6
4
6
5
17
6
52
205
280
66
202
33
53
158
128
155
170
102
44
19
17
70
-0
28
61
80
23
75
3
25
52
35
50
37
40
31
1
6
-1
.0
-.0
.0
.0
2.3
.9
2.6
2.6
.3
.3
.2
.2
.2
.2
.2
.2
.3
.3
.3
.4
.2
.4
.2
.3
.5
.3
1.0
.3
.4
.3
.3
.3
.2-100.0
6143
2541
5673
6896
4225
12J53
3079
4834
4770
37658
10919
5110
1557
2898
5372
1641
40297
LW 57 CORN CREEK SPRING 17S 59E 34 112 1
6-14-71 543 22.2 524 7.65 289 11
22 -.10
3.8
51
33
.0
.2
271
LW 58 BONNIE SPRINGS
6-15-71 544 19.2
22S 58E 02 372 1
782 7.50 356 17
92 -.10
11
91
41
.0
.2
430
LW 59 FLAM RF.S
1- 5-7?
?- 2-7?
7-10-72
10- 1-7?
It- 7-7?
1087
1185
1578
1687
1798
COHP GH 21S 62E
-99.0
17.0
19.4
20. f.
13.9
913
923
1059
1577
1568
7.80
7.76
7.75
7.92
7.76
19 111 3
224
226
225
204
IfiO
22
24
39
135
151
278
282
342
532
497
-.10
-.10
-.04
.28
3.70
3.8
3.8
2.4
3.7
1.9
20
23
26
113
141
3
3
3
6
10
105
97
114
146
141
44
49
54
64
39
.0
.0
.0
.2
1.3
.3
.4
.4
.5
.6
587
594.
691
1101
1065
-------
POINT lOFHTIFTER AMD LOCATION
MO DA YR MUHB TEMP
5- 2-73 2030 25.6
5-30-73 2099 30.fr
T- 2-73 2113 31.1
1- t-73 21*2 3-3 .,3
LH 60 FtftH HASH J
7-26-71 651 23.J
8-31-71 733 24.0
9-27-71 786 19.0
11-11-71 807 15.6
I?- 2-71 922 14.0
1- 4-72 1072 8.1
?- 1-72 1177 8.0
3- 3-72 1272 -99.0
4- 5-72 1334 18. Z
5- 4-72 1385 21.0
6- 1-72 1459 23.9
7-10-72 1580 25.0
8- 7-72 1635 24.4
9- 5-72 1641 20.6
10- 1-72 1686 20.6
11- 7-72 1808 16.1
12- 4-72 1841 13.3
1- 5-7* 1869 -99.0
1-31-73 1905 11.1
3- 5-73 2001 13.3
4- 1-7J 2016 17.8
5- 2-73 19*1 24.4
5-30-73 2100 30.6
7- 2-73 2113 22*2
"»- 1-73 217& 25.6
LH 61 LVSTP INFL
1- 3-72 1039 21.9
4- 5-72 13*7 25.6
conn
tfrM
Prt
6^85
HC03
91
1664- 7.?3 14ft
1768
1552
496?
4679
4892
5280
4555
4299
3783
4085
4504
4387
2912
4712
4826
4330
4510
4539
-99999
4325
3650
4350
4042
3836
4434
7. IT
7.88
?1S 61E
7.59
7.65
7.77
7*74
7.68
7.78
8.19
8.02
7.37
7.84
6.87
7.64
7.63
7.54
7.35
7*51
7.64
7.82
7.94
7.92
7.72
7.37
7.7-2
500ff 7.8r
4765
1878
1188
LH «i2 nLA«?K CO STP INFL
1- 3-72 1055 21.9
4- 5-72 -0 23.9
LH 63 LVH 4 NORTH
7- 7-71 622 -99.9
7- 7-71 625 -99.9
7- 7-71 628 -99.9
ll-tO-71 8?? 8.9
17- 1-71 895 10,8
1- 3-7? 1032 6.9
2- 1-7? llf><; ?.0
3- 2-72 l?5f 9.4
5- '4-7? 1376 15.5
7-10-7? 1530 23.5
1661
1474
5360
5643
6043
3933
3118
325?
13R3
3843
1668
37ft?
7»7fl
21S 62E
7,10
6.97
21S 62E
7.03
6.91
21S 63E
7*95
8.00
8.00
7.77
7.43
7.84
7.57
7.74
7.94
7.81
148
151
t2 413
332
315
327
324
332
321
311
304
327
347
303
323
332
296
329
335
336
341
325
335
322
2M
330
338
262
10 3*2
320
44V
22 222
338
448
29 324
296
290
290
226
211
197
195
243
269
769
CL
375
151
1*8
138
f
383
331
399
395
533
298
226
278
348
330
175
326
327
328
341
312
284
271
221
253
24!
243
310
335
326
1
268
91
1
125
134
2
862
940
99»
565
457
462
457
501
517
485
S04 P04
59V 14.70
53* .98
564 .72
504 .HO
2550 -.10
2222 -.10
2542 -.19
?3
-------
POI1T JDFNTIFIER ANn LOCATION
*0 OA YR NUMB TEMP CONO PH HC03
CL
SO* PO*
NO 3
NA
CA
HG NH*
F OS-SUH
LM Sit DUCK CK AT US 93 21S 62E 27 *3* 1
7-10-72 1573 31.1 3732 6.78 118 623
933 1.78
2.8
*67
33 219
79 10.0
2*28
(£>
LM 65 LVH
11-11-71
12- 1-71
1- 3-72
2- 1-72
3- 2-72
*- 5-72
5- *-72
6- 1-7?
7-10-72
8- 6-72
10- 1-72
10- 5-72
ABOVE LH030
816 13.3
925 15.0
1008 9.0
1158 5.0
12*5 13.9
1337 19.0
1366 17.0
1*39 21.7
152* 21.0
1597 25.0
1685 20.0
1708 20.0
LH 66 HF.Nn STP INFL
1- 3-72
*- 6-72
LM 67 nil
1- 3-72
*- 6-72
LW 68 BC
1- 6-72
*- 6-72
LW ^9 ,BC
1- 6-72
it- 6-7?
1062 19.1
1356 22.2
STP INFL
1063 20.0
135* 21.7
STP INFL
10*2 17.8
1363 22.2
STP EFFL
10*3 5.0
136* 20.6
21S 63E
5678 8.00
5061 7.*5
503* 7.60
5108 7.8*
5896 7.66
5119 7,*fl
5732 7.7*
5*25 7.23
6657 7.57
7183 7.56
5805 7.32
*5* 7.10
21<5 62E
2919 7.01
2733 6.93
220 63E
1500 7.03
1*95 7.31
23S 6*E
15*0 7.00
15J5 6.95
23S 6*E
1762 7.63
189* 7,55
LM 70 FLAM HASH AT LAH9 21S 62E
1- *-7?
2- 2-72
3- 2-72
*- 6-72
5- *-72
5- 1-7?
7-10-72
11- 7-72
1?- *-72
t- 5-73
1-31-73
3- *-73
(,- 1-7*
1073 6.0
1186 10.0
-0 -99.0
1362 25.6 .
138* 31.0
1*56 33.3
15R3 31.7
1809 1*.*
1826 1*.3
1868 -99. H
190* 12.2
1P96 15.6
?0 1 •> 13.9
3285 7.89
*170 8.27
3958 8.09
*279 8.00
*lf.R 8,20
*291 7.69
*1PO 7,78
1.6*3 8.15
1.678 a. 10
l»*91 8.12
*23* 4.*0
(.536 7.98
*?9_5 «.12
28 131 3
211 997
223 895
212 883
205 851
2*1 1110
239 936
250 1052
255 999
2*9 1279
25* 1299
2*5 1365
267 7
36 3** 2
25* *58
371 *19
07 111 1
186 135
3*5 136
09 *31 1
250 132
2*8 163
09 *31 2
271 21*
277 2*3
05 322 1
265 326
239 369
219 359
188 *08
180 *17
298 *22
129 *19
229 ***
278 *1*
283 399
136 *16
167 *02
1B6 *30
1380 11.00
1386 10.50
139* 10.30
1378 12.60
1732 6.00
1506 10.50
16*2 B.*0
1529 10.70
1889 3.00
188* 1.70
1856 .6?
26 -.00
607 35.00
558 31.00
328 53.00
280 29.00
305 51.00
298 *5.00
367 3*. 00
*12 22.00
1735 -.10
1912 -.10
1922 -.10
2080 .08
19*9 -.0*
2073 .10
18<»8 -.0*
2155 -.0*
2131 -.0*
2101 -.0*
2157 -.0*
2100 -.0*
?0«5 -.0*
58.0
66.0
58.0
63.0
61.0
*7.0
*9.0
*2.0
58.8
53.0
56.0
1.7
*.6
3.9
.6
.3
.5
.*
.3
.3
3.6
2.1
.9
.3
-.1
.1
.2
.9
1.8
*.6
2.5
1.2
.6
567
*96
53*
512
612
551
595
588
663
653
678
16
360
33*
157
168
175
183
22*
250
?*5
262
259
280
282
30*
291
319
309
299
303
29*
28*
63
62
53
56
7*
59
67
66
81
8*
9*
3
18
19
11
12
15
1*
15
19
18
19
17
18
16
19
18
20
23
21
23
20
19
*3*
*23
*02
387
*86
*16
50*
**1
581
59*
611
29
173
167
88
8*
75
85
10*
96
365
368
3*1
372
362
*09
326
383
396
382
371
369
379
187
182
176
177
220
186
207
197
2**
25*
269
3*
65
67
29
32
28
31
35
39
2*8
295
290
309
296
313
273
326
313
31*
316
307
299
.0 1.0
2.1 1.0
.8 t.O
.2 1.0
.2 1.0
.2 t.l
.2 t.l
.6 t.l
.1 -.0
.1 1.0
.2 1.0
.2 .7
19.1 .7
29.0 .9
1*.* .2
28.0 .7
31.2 .*
20.0 .3
20.5 .3
13.0 .2
.0 .*
.0 .6
.0 .6
.0 .5
.0 .6
.0 .6
.1 -99.0
3.7 .6
.1 .6
.1 .5
.3 -99.0
.1 -99.0
.1 -99.0
3802
363*
3616
3538
**21
3831
*2*9
*000
*921
*9*8
5051
2*8
1865
1811
908
9*0
936
963
11*8
1231
3071
33*5
3298
3561
3*51
3687
3289
3765
3725
3661
3656
3575
3588
-------
POIMT imtNTIFIER AND LOCATION
W
MH D» Y9 NUMH TEMP
5- 2-73 1979 35.6
•5-30-73 2091 25.0
7- 3-73 2111, 2B.3
'8- 1-73 2176 33.3
LW 71 UPPF.R PONP SEEP
1- *-72 1071 6.0
?.- 2-7? 1189 10.0
3- 2-72 126ft -99.0
7-10-7? 1570 28.9
CONfl PH HC03 CL
*180 7.87
*37* 7.78
1.296 7.89
I,?** 8.00
21S 63E
9*13 7.65
- 9070 8.01
8928 7.85
11,578 7.67
LW 72 FLAM WSH AT EMRSN 21«5 61E
1- *-72 10*1 8.1
?.- 1-72 1178 6.0
7-11-72 1587 27.2
11- 7-72 179* -99.9
12- *-72 18*2 11. 1
1- 5-73 1*70 -99.0
3- 5-73 2000 11.1
t»- 1-73 2017 13,3
5- 2-73 i<»«2 17.8
5-70-73 2101 22.2
LW 73 Nf COR LOW POND
I- *-72 1077 6.0
?- 2-7? 1192 8.0
3-10-72 1278 -99.0
6- 1-72 1**B 28.9
7-10-72 1567 23.9
1- *-73 1652 -99.0
LW 7U FLAM RF.S DRAIN
1- 6-72 107f) 16.1.
?- 1-72 1179 16.0
7-U-72 1588 3*.*
11- 7-72 1795 18.3
1- "5-73 1872 -99.0
3- 5-73 1998 17.8
*- 1-73 2018 17.8
5- 2-73 19&7 18.9
5-30-73 2097 23.3
7- 2-73 2120 22.8
8- 1-73 2179 18.9
LW 75 FLAM RFS DSAIN
6-1U-71 5<»5 21.7
H-31-71 732 20.6
7-10-77 1579 20.0
11- 7-72 1796 17.8
1- 5-73 187T -99.0
3*73 8.00
3**0 7.9
-.10
-.10
-.10
.08
.11
.08
-.10
-.10
1.06
-.Ofc
-.01,
-.0*
-.0",
-.0
-.Ofc
- 10
- 10
- Ofc
- 01,
- 01,
N03
. 1.
-.1
.2
.2
172.0
179.0
165.0
19>«. 0
2.2
5.0
2.6
2.3
3,8
6.0
3.3
3.3
.6
.5
13.0
21.0
17.7
26.0
8.5
l».0
8.7
7.7
3.1,
2.3
3.1.
.5
I..O
l>.2
(,.9
I..1
(,.9
3.0
2.7
J.I.
10. <,
15.1.
NA
277
292
300
321
1170
1072
1080
1955
190
176
366
193
202
196
185
172
129
166
1991.
2016
201,0
21.30
2706
1597
-
95
81,
169
30
36
39
1,1
1,0
1,2
1.1.
1.3
38
2
.0 .(>
.0 -99.0
.0 .<,
.2 .<,
.2 -99.0
.2 -99.0
-.1 -99.0
-.1 .1,
.1 -99.0
.1 -99.0
.0 . 1.
.0 .<.
.0 -99.0
.0 .It
.1 .5
3519
3600
33<»7
3*69
7213
6770
7012
11192
Z969
2827
*320
2951
2995
2999
2950
2820
2281
2733
8266
8313
861*
1051*
11527
6721
1322
1218
1293
753
806
872
90*
923
977
1035
1057
68*
571
879
15*5
1682
-------
POTNT IDPNTIFIER »NO
MO OA YR NUMB TFMP CONn PH HC03
1- 5-73 1999 17.8 2434 7.74 240
4- 1-73 2019 16.7 2213 7.79 233
5- 2-73 2038 18.9 1544 7.69 208
5-30-73 2098 20.0 1584 7.85 214
7- 2-73 2121 22.2 1638 7.98 208
8- 1-73 2180 -99.0 1682 8.00 184
LW 76 CCSTP OUTFL FLUME 21S 62E
5- 2-73 1974 24.4 2400 7.11
5-30-73 2096 26.7 2760 6.63
7- 2-73 2118 28.9 2817 7.15
8- 1-73 2172 28.9 2192 7.80
LW 79 LV GK AT FNSY PRK 2BS 61E
9- 6-72 1650 23.3 630 7.17
LW 80 LV CRK AT MAIN ST 20S 61E
9- 6-72 1651 E2.8 497 7.03
LW 81 LV CRK AT RBNCHO 20S 61E
9- 6-72 1652 22.8 319319.00
LH 82 LV CRK AT BEDFORT 20S 61E
9- 6-72 1653 23.9 2470 6.98 ;
LW 83 LVH BELOW LH065 21$ 63E
12- 4-72 1837 15.6 7187 7.43
LW 84 SAHARA-NEV. C.C. 21S 61E
1-31-73 1908 12.2 2716 7.52
LW 85 LEROY APTS. 2 MRLNO PKHY HARRS 20S 61E
1-15-73 1875 17.2 1878 7.72
LW *>1 B-flLLARH NO ESTRN 215 61E
1-15-73 1876 19.4 4119 7.67
LW 88 MONT WARDS 21* 61E
1-15-7-3 1877 23.3 450T 7..61
22 242
133
303
143
26 322
245
27 343
171
29 443
128
31 214
1090
28 131
257
14 142
355
26 331
395
26 331
316
02 til
365
or 211
321
CL S14 P04 N03 N«
225 787 -.04 10.0 126
213 761 -.04 13.1 128
128 532 -.04 6.0 75
134 532 -.04 5.8 81
13fr 534 -.04 4.8 97
153 561 -.04 6.2 131
1
310 563 19.50 2.8 268
454 606 18.50 2.5 323
408 603 IB. 70 1.6 326
380 588 17.00 4.3 321
1
33 112 1.30 .8 25
1
20 92 1.60 .8 19
1
1? 40 2.20 .3 7
1
7 30 1.50 3.4 7
-3
1382 1946 .48 52.0 677
135 ,,1280 -.04 3«3 142
1
88 1080 -.04' 8.9 108
2
66 748 -.04 9.1 82
213 2076 .20 13.3 276
312 2184 -.04 12.-3 397
K C« MG NH4 F OS-SUM
4 200 125 .1 -99.0 1595
5 199 119 .1 -99.0 1552
-1 151 78 .1 -99.0 1072
5 150 81 .2 .4 1094
23 156 78 .2 -99.0 1132
6 170 80 .2 -99.0 1197
13 135 64 36.0 -99.0 1551
16 146 76 28*0 .5 1737
33 151 73 30.0 -99.0 1794
22 157 57 22.0 -99.0 1639
9 95 20 .0 .3 416
9 58 13 .0 .2 299
4 47 9 .0 .2 183
4 34 6 .5 .1 630
90 638 273 .0 1.1 5186
f
18 290 172 .0 .8 2215
18 165 210 .0 .3 1871
9 137 146 .0 .3 1353
88 257 M7 .0 .5 3421
4t 258 370 .0 .3 36ff3
-------
POt NT
MO <1A
IDENTIFIER AND LOCUTION
YR NUMB TEMP CONn PH HC03 CL SOI» POt. N03
NA
CA
NH«»
F OS-SUM
LM >»9
1-16-
CORTZ PRKING tT 20S 61E 3k 131
75 1879 20.6 1 8?7 7.51 356 105 557 .20 -.1 17<» H 120
70
.«. 1220
LW 90
1-19-
CONV CNTR 21S 61E 10 331
77 1883 20.0 3019 7.61 270 98 1551 -»0<» 29.3 153 11 291
.3 2<>80
K 91
1-19
DUNES HO 2f> 61E 20 ll«t
•73 1881. 27.8 2151 7.58 151. 7« 1083 -,fltt 3.
-------
Appendix 4. Chemical Analyses Used to Determine Historical
Changes in Ground-Water Quality
196
-------
location
19/60- 9odal
9cdal
9cda
9abbl
9abbl
9abb
21cccl
23bbcl
23btel
23bbc
27aabl
27aabl
27aab
20/60-24b
24adbl
24aaa
20/61- 3dabl
3dabl
3dabl
3dab
4addl
4add
13adcl
13adcl
13adb
13adb
14dddl
ISabl
15bl
16bdbl
ISbccl
ISbccl
ISbcc
19abdl
19ddcl
19dda
s
MJ
DM
LG062
MJ
DM
LG061
MJ
MJ
DM
LG113
MJ
DM
LG114
C
HM
LG112
MJ
M
DM
LG066
HM
LG119
M
DM
DRI
LG117
M
M
C
M
MJ
.DM
LG126
MJ
MJ
1X3121
f •
f$
612
612
612
706
706
716
8
560
560
920
605
605
605
232
385
312
242
300
350
350
850
900
930
930
300
300
402
1700
386
412
412
500
260
280
295
*p U>
j§ *"
28 £ I
10-23-44
03-15-63
10-04-72
09-13-45 c
1962-3 ?
10-04-72
09-13-45
10-25-44
03-15-63
06-08-73
10-23-44
1963
06-08-73
09-14-12 1.37 A
10-16-30 0.05 A
06-08-73
05-01-41
10-16-56
11-09-62
10-05-72
10-12-31 1.6
06-12-73
01-24-47
04-11-63
01-^31-68
06-08-73
01-24-47
04-20-56
09-16-12 0.9 A
01-21-47
02-16-45
11-26-62
06-08-73
10-23-44
06-08-73
Calcium
46
43
46
38
38
43
55
46
40
39
44
48
41
52
57
52
54
48
51
44
12
32
54
32
34
36
46
14
53
44
46
56
47
49
48
48
Concentration of principal ions, mg/S.
1 "1 if*
26
30
25
28
28
26
29
26
24
24
27
15
24
3
32
36
15
23
25
23
19
19
32
44
26
37
27
11
27
23
26
76
22
26
26
22
6.9
9.4
10.3
7.9
17.4
6
8.6
18.4
221
139
7.2
7.0
4
8
7.8
5
30
10.7
3
4
8
11.6
8.9
0
9
43
18.9
24
24
9.5
71
21
20
10
27
24
0.9
182
26
2.8
12
23
7.8
4.8
8.7
8.6
0.92
1.3
1.3
1.1
1.5
1.1
0.93
2.6
2.4
43
0.6
1.6
250
246
243
240
244
247 12
274
250
232
239
247
300
239
235
249
262
237 tr
232
246
231
220
193
205
266
218
251
226
284
251
212
212 21
288
234
238
242
235
19
31
31
22
21
21
31
19
17
20
23
12
26
34
41
75
45
34
2
33
72
38
129
50
24
69
35
114
33
27
30
5
59
32
34
36
Chloride
5
5
3.4
3.9
4.0
5.9
2.8
5
6
6.2
8.8
32
4.3
4
9.3
20
7
4.9
15
4.94
7.1
3.9
3.2
8
4.5
17.8
3.5
8
55
4.8
5.3
5.8
3.8
7.1
6
3.9
Nitrate
1.5
2.2
2.9
2.4
1.3
11.5
1.5
1.3
0.6
1
1.9
0.8
0.3
1.4
2
2.2
Dissolved solids
m/{.
350
202 274
338
200 258
394
350
190 237
358
246 206
251
208
194 245
249
202 276
200
341
218 358
334
225
484
258
208
352
236 243
357
364
223
238
234
215
253
229
256
223
209
221
233
255
224
253
263
341
262
233
238
229
289
209
340
275
240
309
224
469
317
207
245
307
227
236
242
236
Specific cond
(microratos/on)
430
424
467
442
417
420
433
613
421
412
384
551
487
549
424
721
382
434
429
428
432
434
(0 D
221
220
211
216
256
222
200
219
472
141
196
232
266
260
226
80
243
204
222
176
224
Appendix 4 (continued)
-------
00
Location
20/61-20caa
20caa
20caa
20caa
20cacl
20cacl
20cab
20cbcl
20cdcl
20cdcl
21
22bl
27
27cl
27cl
27adbl
27cddl
28cbdl
28cbdl
28cdal
28cda
28cdal
28cdal
28dacl
28dacl
29cbc2
29cbc
29cbbl
29cccl
29dbbl
29dbbl
29dcal
29dcal
30dd
SObbbl
30bbbl
j
DRI
LG068
LG067
DRI
HM
DM
1G069
MJ
MJ
DM
M
C
C
HM
HM
MJ
MJ
MJ
DM
MJ
LG070
MJ
DM
MJ
MJ
HM
U2.27
HM
MJ
MJ
DM
MJ
.DM
C
HM
DM
i!
300
300
665
665
347
347
400
278
325
325
125
28
357
660
660
440
440
690
690
640
805
600
600
375
475
475
664
664
350
350
$3
38
01-31-68
10-05-72
10-05-72
01-31-68
09-15-44
11-26-62
10-11-72
10-18-44
10-18-44
11-26-62
07-21-52
09-16-12
09-23-12
08-31-25
08-31-25
06-14-35
01-19-45
12-14-62
10-25-44
10-11-72
10-25-44
12-19-62
01-19-45
01-19-45
02-05-32
06-08-73
02-05-32
10-02-42
10-18-44
1962-3
10-24-44
11-26-62
09-23-12
03-27-31
11-26-62
"in
3 jg
**
0.5 A
Y
Y
Y
9
T
T
1.1
0.7
S
5.74 X
1.1
Calcium
104
58
55
64
44
80
63
49
49
37
164
53
60
187
147
78
57
43
54
38
89
38
40
46
40.
64
49
36
60
48
120
46
54
56
51
56
Concentration of principal
82
43
32
42
14
0.97
42
26
26
19
27
47
607
147
21
9
23
27
22
63
24
29
22
22
20
23
22
19
25
0
25
33
23
24
48
68.3 76 8.1
16.4 18.2 1.8
9.7 11 1.3
16.5 19.6 3.1
33
0
16.2 18.1 1.9
5.9
4.6
16
190
26
23
738
66 57
9
33
10
34
10
21 25 3.5
11
27
6.7
9.2
7.9
7 8.9 1.9
5.1
11
5.7
3.7
6.2
0
17
7.6
0
335
242
234
250
237
305
258
242
238
298
243
251
273
203
444
249
232
221
216
210
338
192
224
171
210
233
233
181
220
236
254
227
293
239
249
228
ions, rag/S.
1 *
457
134
72
117
30
5
134
33
36
20
417
33
141
3839
695
61
22
31
11
27
183
6 33
5
24
30
58
40
32
45
33
257
32
5
43
38
12
Dissolved solids
i? 1 c
d) .H ^J O
ana a *J
M Id rH rH 0 g
30
17.8
13.3
15.8
10
63
14.5
6.2
5.3
31
136
55
18
288
19.4
22
28
6
5
5
61
6
12
11
5.3
5.5
5.3
7.1
13
5.3
150
7.1
6.3
2
tr.
57
6.4
3
194
250
5.1
244
2
tr.
204
190
218
6.3
192
2:5
180
208
240
6
236
1084
507
361
359
1190
258
323
335
334
312
310
280
317
265
354
343
240
237
263
455
6332
1462
260
607
235
190
606
254
267
247
218
914
396
301
381
248
299
403
239
238
270
1026
319
423
5760
1349
313
263
222
237
205
593
212
223
194
210
270
243
191
256
233
656
228
242
265
243
285
Specific cond
(ynihos/cin)
1180
652
519
678
664
427
1700
402
375
957
335
408
557
443
404
429
423
m O
10 O
M in
ID nj
167
204
227
230
172
243
343
281
179
200
248
185
193
220
203
192
228
224
216
222
234
227
336
Appendix 4 (continued)
-------
Location
20/61- 31aad2
31dacl
32acb2
33ccal
33ccal
20/61-33cca
33cca2
33cca
33ccb2
33ccb
34adcl
34adcl
34bcbl
34bcbl
34bcb
35cbb2
35cbb2
35ccb
35ddc2
36bbbl
36bbbl
36bbb
20/62- Ibbcl
3dabl
4addl
4addl
4 add
Sacd
8acd
9abcl
9bccl
18bbc
18bbc
19hbbl
19bbb
19cabl
19cab
30
ig To
ffi IH
-P ,0
O A 4J OJ
jj 53 q) a) ,-H a
3 o< o fl H 8
0 aT*! mo i-4
M fi>- 3 O E
M
M
MJ
MJ
MJ
LG073
MJ
IG122
MJ
LG072
MJ
DM
MJ
DM
LG074
MJ
DM
LG123
MJ
MJ...
DM
IG063
M
-A
MJ
M
I£118
DRI
LS065
M
M
DRI
LG064
MJ
IC116
MT
LU115
M
500
940
660
200
400
400
226
226
425
425
354
354
780
460
460
460
418
325
325
325
1247
504
800
790
800
120
120
1000
1000
300
300
289
200
132
11-02-51
05-16-52
02-16-45
10-11-72
02-21-38
06-08-73
10-11-72
01-19-45
1962-3
06-14-41
04-11-63
10-12-72
09-14-45
12-19-62
06-08-73
09-14-45
01-19-45.
10-29-62
10-05-72
03-02-55
10-16-56
05-05-41
10-17-56
06-08-73
12-31-67
10-05-72
10-17-56
10-17-56
12-31-67
10-05-72
12-17-45
06-08-73
12-17-45
06-08-73
10-27-52
Remarks
Calciutn
50
48
46
e 46
T 47
93
84
44
49
92
28
53
84
35
42
31
40
42
39
44
20
43
47
46
60
43
35
32
29
39
38
26
24
25
26
39
24
162
-H
26
25
25
28
26
73
tr.
26
13
95
19
4.9
25
24
21
22
29
23
26
26
30
25
43
23
17
23
25
35
34
19
25
46
44
10
34
15
29
Concentration of principal
§
*J I §
§ § in °* *8
8
35
7.3
80
7.6
9
7.9
46
7
18
18.3
15.1
15.9
91
49
11
12
27
15
11.6
11
9.2
12
40
32
10.7
26
91
11
33
50
9
9.9
4
18
11.7
5
10 .
86
9.6
51
8.8
15
22
21
19.3
18.8
98
55
14.1
14.2
56
31
84
16.8
175
3.6
4.6
2.4
11.1
2.3
2.7
,
1.7
4.5
1.8
3.8
2.8
4.2
2.9
7.1
5.8
3.1
2.2
4
1.8
238
222
235
233
233
271
270
225
231
292
162
300
305
203
209
162
224
204
206
233
188
235
198
232
244
252
243
258
267
228
256
278
286
204
249
221
200
218
Carbonate p
a
Sulfate ^
43
51
40
44
46
316
47
46
3.6 25
457
26
24
144
31
37
tr. 32
6
46
tr. 40
36
0.3 6
39
171
32
34
25
29
26
26
162
88
34
34
35
48
110
37
451
1
3.5
6.5
7.1
8.8
8.8
62
7.0
4
7.8
73
8.8
46
16
5
6.7
6
14
5.3
3.2
7.1
13
5.9
39
4.5
12
5.8
7.5
4.9
6.7
18
8.6
3.8
4.9
15
8.3
32
7.3
75
Nitrate
2.1
1.
3.3
2
4.9
1.9
U9
v
2.2
2
1
2.4
3.3
1.7
0.7
0.9
0.93
1.1
1.8
Dissolved solids
ras/i
1 1 1
365
369
373
221 280
357
255
246
250 460
166
256
184
319
356
154
200 255
374
402
28 294
181 408
1050
267
301
256
148
168
522
248
272
486
399
242
265
245
251
254
720
303
242
238
956
172
308
469
204
221
175
217
230
214
238
248
239
450
229
258
245
240
243
247
449
341
261
278
241
270
389
214
970
Specific cond
(prrihos/oh)
430
447
441
447
446
1074
438
423
1415
326
397
339
414
377
424
438
748
413
440
519
483
454
728
575
520
491
486
399
1500
Hardness
(as CaC03)
232
222
220
229
225
210
177
148
152
312
188
166
220
205
216
176
294
230
220
201
176
199
102
159
appendix 4 (continued)
-------
O
O
location
21/61- Ibba
Icdcl
2cbbl
3a
3abb2
3abb2
21/61- 3bcc2
4aadl
4baal
4baa
4dacl
4dacl
4dac
4dac2
4dac2
4dac
4ddfal
6accl
7accl
7accl
9acdl
lOcdal
13bdbl
ISbccl
ISbccl
ISdbdl
21bbbl
22cccl
23ccbl
24aad
24aad
24aad
24aad
25cabl
25cabl
25cab
27ctbl
27cccl
28d
28bccl
,
1X3075
M
MJ
C
MJ
MJ
«7
MJ
MJ
LG071
MJ
DM
IC125
MJ
DM
LG124
MJ
M
MJ
MJ
MJ
M
M
M
EM
HM
MJ
M
M
DKt
LG078
DEI
LG077
M
DM
U3079
C
MJ
HM
M
53 m
CU (u
STifi
400
1120
442
807
800
793
381
400
810
810
810
650
650
650
400
394
355
550
931
260
892
892
300
325
500
100
100
150
160
400
263
224
176
•P O
S8 1
10-12-72
01-21-47
01-19-45
09-23-12
09-14-45
09-14-45
10-10-35
01-19-45
01-19-45
10-11-72
05-19-41
04-16-63
06-11-73
10-25-44
04-16-63
06-11-73
10-09-45
07-06-47
03-15-45
03-15-45
10-17-44
04-13-53
01-21-47
01-23-47
1962-3
09-10-30 0.3
10-17-44
01-06-47
01-23-47
01-29-68
10-13-72
01-29-68
10-13-72
01-20-47
02-23-63
10-13-72
09-18-12
10-17-44
10-27-30 0.6
03-06-43
Remarks
Calcium
23
49
32
54
6 45
T 40
51
41
31
71
60
62
49
36
61
54
60
54
8 49
T 48
45
143
60
47
46
\ 68
40
65
72
70
178
74
98
139
128
86
85
61
a 81
72
•H
20.2
26
18
25
26
23
13
23
27
112
18
38
25
26
37
29
17
29
28
27
24
29
25
22
32
24
32
37
32
108
36
56
51
50
31
31
31
25
21
Concentration of principal ions, mg/J,
11.6 15.5
3.9
50
10
4.1
5.5
26
17
29
62 70
2
11
8.9 11.3
10
8
10.6 13.5
2
11
7.1
10
11
521
10
4.1
12
12
9.2
7.8
15
10 13
115 120
19.4 23
42 45
7.4
8
106 110
10
20
31
18
3.9 165
223
152
251
218 tr.
199
210
223
236
8.3 11.9
220
232
2.4 222
174 16
,229
2.9 220
195
231
232
232
223
95
227
211
203
243
204
227
216
3 221
5.1 261
3.3 216
2.6 242
218
207
4.3 161
210
253
245
220
35
47
124
39
41
39
50
37
46
671
32
125
61
42
115
90
44
74
51
52
39
1050
71
47
56
109
40
106
165
109
741
115
302
357
280
307
165
101
148
116
Chloride
4.4
3.5
6.2
10
2.8
3.2
10
9.6
7.1
62
10
10
5.8
5.0
8
7.8
10
5.0
5.3
7.1
8.8
210
2.5
3.8
5
10
5.3
7.0
8.8
7.5
157
17.3
57
14
17
96
10
11
12.2
3
Dissolved solids
& | g
1.6
1.3
382
337
310
172 225
351
376
1.06
228
190
2.1
309
188
2.4
160 265
3.5
372
376
350
2100
2.9
1.4
166
322
4.3
1.4
452
11.2
480
6
2.3
170
2.7
4
478
400
241
318
388
370
290
278
233
266
329
334
406
678
753
430
410
181
240
305
261
226
209
253
237
256
993
230
360
264
221
342
304
229
290
254
258
237
1971
287
232
241
350
219
334
405
339
1444
370
682
678
585
712
408
348
418
338
Specific cond
(yrrtras/cm)
335
428
508
423
398
418
448
1380
469
404
529
501
458
458
424
3000
485
420
399
560
657
594
2006
667
1039
1000
1120
544
to o
w 0
-------
Location
21/61-29ddal
30a
30d
34
34abcl
35dccl
21/61-35dccl
36adcl
21/62- 3al
3bbb
4aaa2
5bb
17ddcl
17ddcl
19acdl
19acdl
19acdl
20dddl
21dddl
27bcbl
27bcdl
27cbal
27cccl
27 ?
28aadl
28acdl
28adal
29bccl
29ccbl
29ccbl
29cccl
29ccc
29dhb
29dbb
30ac
30-
30dbfal
30dbbl
30dbb
30dcbl
30dcbl
30d
!
MJ
HM
HM
C
M
HM
HM
M
C
LG083
HM
C
MJ
DM
M
M
DM
MJ
MJ
i>lJ
MJ
MJ
HM
HM
MJ
C
MJ
MJ
MJ
A
MJ
IXJ076
• c
LW012
C
HM
MJ
DM
LG082
M
DM
M
4$ 01
Qj 0)
s£i
260
405
246
300
485
200
180
546
540
540
114
200
458
525
450
420
375
500
420
570
700
1165
404
404
405
500
390
390
390
400
400
140
1 I J
8 i
S3 8 {
as g J
10-17-44
08-05-27 0.25
09-21-12 0.07
09-18-12 0.09
01-06-47
08-05-27 0.05
08-05-27 0.05
01-20-47
12-24-12
10-20-72
04-19-29
12-24-12
03-18-42
11-09-62
01-23-47
05-20-57
06-04-63
12-21-42
07-13-42
07-13-42
07-13-42
07-13-42
09-27-26
03-21-33
07-13-42
09-20-12
07-13-42
08-04-42
07-13-42
03-08-45
07-13-42
10-12-72
12-24-12
12-02-71
09-21-12 0.08
03-04-25 0.2
08-04-42
06-04-63
10-17-72
01-20-47
05-22-63
10-21-57
u
67
517
102
134
e 64
T 151
116
137
a 58
32
142
*. 500
228
254
42
X 123
122
66
246
148
240
158
610
a 162
n 162
»Y 295
282
64
79
80
110
66
5 275
5 286
102
282
110
91
106
106
120
460
Magnesium
34
197
49
47
30
52
39
56
38
18.5
94
150
68
82
22
37
33
20
98
46
119
45
358
71
63
164
188
34
39
46
50
39
130
143
49
172
42
48
53
47
56
Concentration of principal
8
7.3
353
10
18
11
35
42
22
34
19.2 23 3.9
120
1509
678
136
14
53
27
25
765
511
544
504
805
651
573
297
474
11
33
21
29
29 34.7 5.7
99
132 156 24
10
500
18
9
24 30 6.5
29
26
19
227
263
204
207
223
219
163
205
254
192
254
51
154
793
194
217
207
144
78
81
107
81
204
80
81
197
181
181
195
206
215
199
239
225
204
165
160
198
212
232
207
202
Carbonate §
1
Sulfate 75
118
1735
1278
358
107
418
358
392
11C
4V
681
tr. 4008
1599
2060
55
357
360
134
2252
1356
1678
1372
2855
1735
1600
12 1233
1641
147
232
240
327
229
959
1137
278
1273
315
245
358
295
360
820
1 1
8.8
601
15
17 1.5
6 3.9
38
22
29 2.4
11
5.49 1.6
60
658
378
390
5.2 1.3
16
21
15
192
136
308
128
1140
169
161
417 0.5
460
16
20
11
20
10.8 2
172 0.3
168 2.1
15 0.75
737
20
17
17.7 2.4
13
26
121
Dissolved solids
mg/4
126
650
170
118
64
66
88
66
66
148
148
160
176
131
162
-
170
462
3113
744
371
3705
2360
3050
2388
2820
3250
420
580
603
715
602
1670
3667
617
713
332
912
745
740
545
1306
7355
3717
841
756
6378
2734
2827
2102
617
3303
582
606
810
347
3535
554
677
328
802
660
739
376
223
1222
6850
3027
3312
235
693
665
331
3591
2237
2942
2247
5868
2828
2599
2515
3134
361
499
499
642
479
1753
2004
555
3045
584
507
672
604
690
1520
Specific cond
(ymhos/cm)
574
564
1520
395
419
1025
1180
783
744
891
890
To
5 3
fll (Q
306
528
283
572
300
1865
849
972
196
520
247
1017
559
1088
580
663
1410
1476
299
357
357
480
1220
456
447
424
458
528
.
Appendix 4 (continued)
-------
Concentration of principal ions, mg/il
Dissolved solids
to
o
NJ
Location
20/62- 31bdc2
31bdc
34b
22/61- Ibcb4
Ibcb4
Ibdbl
Ib
Id
Idacl
Idacl
Idacl
2abal
2aba2
3accl
3accl
3caal
3ddal
3dda
lObdal
lObdal
lObdal
Ilbac2
Ilbac3
Ilbcb4
12bbbl
12bbbl
12bbb
16al
22/62- Icbal
Icbcl.
Icbcl
Icbc2
Icbc2
Icccl
Icocl
9dccl
12aacl
12aacl
}-J 4^ 0) (U i-f
3 ft (B -O rH
O QJ U-) trt n
05 Q-- O O
MJ
LGOS4
HM
DM
HM
HM
HM
HM
MJ
DM
LG081
MJ
DM
MJ
DM
MJ
MJ
LG080
C
HM
DM
MJ
C
C
MJ
DM
Ijca.20
HM
MJ
MJ
DM
MJ
MJ
MI
DM
MJ
M
DM
600
600
375
209
209
209
209
200
200
395
335
335
305
305
305
175
412
100
65
465
1135
1135
850
300
300
180
200
200
07-13-42
10-20-72
09-27-26
06-20-63
09-25-30
09-25-30
09-25-30
09-08-30
07-13-42
1962-3
10-13-72
10-17-44
06-20-63
07-03-41
06-20-63
07-03-41
06-15-45
10-13-72
09-18-12
10-13-30
06-20-63
03-28-45
09-17-12
09-17-12
10-17-44
06-20-63
06-12-73
09-07-26
07-13-42
03-15-45
03-14-63
03-15-45
07-13-42
09-24-45
12-19-62
11-09-42
05-23-45
1962-3
$i m §
s 3 'o
1 I 3
147
90
610
8 178
0.25 161
0.25 229
0.25 294
1.0 165
177
131
171
134
134
148
158
150
158
148
1.18 155
166
1.15 178
140
0.71 177
0.67 » 193
120
126
120
188
210
106
240
Y 120
76
174
203
98
81
192
|
50
49
358
99
56
94
118
58
56
56
61
57
70
40
59
44
53
54
60
55
57
52
56
73
51
53
51
51
50
20
24
31
9
85
30
56
29
40
3 II 1
8
23 29 5.9
805
38
65
128
156
67
44
36
57 14.6
2.3
2.2
55
11
40
0.7
44 54 10.3
15
57
45
25
47
104
58
0
23 29 6.2
102
253
436
64
536
743
378
269
124
189
647
.%
158
116
204
203
226
182
202
220
207
203
207
198
190
207
195.
171
176
196
205
220
198
202
215
191
157
203
205
329
117
84
110
323
160
102
234
176
134
90
jg
-------
EXPLANATION
A. Location
The locations and sequence numbers shown are generally identical to
those in the source documents with exceptions noted in the remarks column.
B. C Carpenter (1915)
EM Domenico and Maxey (1964)
DRI Center for Water Resources Research, Desert Research Institute
(unpublished)
HM Hardman and Miner (1934)
LG075 Present study; Appendix 2 for description of
sampling points
M Malmberg (1965)
MJ Maxey and Jameson (1948)
C. Measured or estimated discharge of flowing wells on the date of sampling.
D. Concentrations shown are mg/JL Specific conductance is expressed as
microrihos/cm. Values shown are rounded off as follows:
Reported concentration rounded to
n _< 1 mg/£ nearest hundredth
1 < n < 21 nearest tenth
n >21 nearest whole number
Total dissolved solids are expressed as "total", "evaporation" and "summation",
with the latter calculated as the sum of the ionic constituents, after
converting bicarbonate to carbonate. Concentrations expressed as "total"
or "evaporation" are taken, as they appear, from previous reports.
Remarks
Y Shallow well
A Located in 20/60-24adb by Maxey and Jameson (1948).
& Incomplete analysis indicated by poor ion balance.
6 Shallow flow (Maxey and Jameson, 1948).
T Deep flow (Maxey and Jameson, 1948).
£ Grapevine Spring; located about 9 miles southeast of Las Vegas in
21/62-28 according to Hardman and Miller (1934), actual location
21/62-29dbb.
n Located in 21/62-28 by Carpenter (1915).
a Located in 21/61-33bac by Maxey and Jameson (1948).
a Shallow well, 30 feet to water; located in 21/62-3b and 21/62-3a by
Carpenter (1915) and Hardman and Miller (1934), respectively; latter
location agrees with map presented by Carpenter.
$ Located in 21/62-5bfo and 2V62-3bacl by Carpenter (1915) and Maxey and
Jameson (1948), respectively.
A E.M. Taylor ranch (Kyle or Park); located in 20/61-22b by Carpenter
(1915).
203
-------
A Las Vegas Spring
ft Low yield artesian well approximately 500 feet deep located "near
Whitney, 8 miles southeast of Las Vegas" (Hardman and Miller, 1934).
** Stated to be 665' TD and located in 20/61-20da in 1968 (DRI) report.
£ Originally reported 631' TD. Driller's log indicates 706' TD with 631'
cased.
V Located in 21/62-10cddf by Malmberg (1965).
Located in 22/61-lb by Carpenter (1915).
3 Located in 22/61-lbd4 by Domenico and Maxey (1964).
f Located in 21/61-8 and 21/61-18dbd, by Hardman and Miller (1934) and
Maxey and Jameson (1948), respectively.
204
-------
Appendix 5. Characteristics of Wells Used to Determine
Historical Changes in Ground-Water Quality
205
-------
Well Location
# T R S
Address
Depth Cased Perforated
(feet) (feet) from - to
Date
sampled
Remarks*
LGQ61 19/60- 4cda Tule Springs Park
706
631 531 - 631
LG062 19/60- 9cda
LG063 20/61-36bbb
LG364 20/62-18bbc
LG065 20/62- 8aba
LG066 20/61- 3dab
LG067 20/61-20caa
LG068 20/61-20caa
LG069 20/61-20cab
Gilcrease Ranch
480 N. 25th St.
3115 L.V. Blvd. No.
4229 L.V. Blvd. No.
Nellis AFB Well #2
612
325 300 None
300
120
350
300
120
55 - 120
70 - 115
3087 W. Lake Mead Blvd. 665 570 394 - 570
3001 W. Lake Mead Blvd.
226 Anderson La.
LG070 20/61-28cda 1531 W. Bonanza Rd.
300
400
440
75
400
None
LG071 21/61- 4baa
1823 E. Charleston Blvd. 400
10-04-72 Original; sampled 09-13-45 (MJ),
1962-3 (DM); irrigation and
domestic supply well; listed
incorrectly in earlier reports
as 631' TD
10-04-72 Original; sampled 10-23-44 (MJ),
03-15-63 (DM); irrigation well
10^05-72 Original; sampled 01-19-45 (MJ),
10-29-62 (DM); artesian; domes-
tic well
10-05-72 Original; sampled 12-31-67 (DRI)
10-05-72 Original; sampled 12-31-67 (DRI);
reported as 200' TD in 1968 (DRI)
10-05-72 Original; sampled 05-01-41 (MJ),
10-16-56 (MB), 11-09-62 (DM);
public water supply
10-05-72 Original; sampled 01-31-68 (DRI);
deepened from 300" in 1947, flow
increased to 0.2 cfs @ 665' TD
10-05-72 Original; sampled 01-31-68 (DRI)
10-11-72 Substitute for 20/61/20cac 1(«J),
347' TD, sampled 09-15-44 (MJ),
11-26-62 (DM)
10-11-72 Substitute for 20/61/28 cdal,
(MJ)(shallow flow), sampled
10-25-44
10-11-72 Substitute for 21/61/4baa (MJ),
381' TD, sampled 01-19-45
Appendix 5 (continued)
-------
to
o
Well
#
LG072
LG073
Location
T R S
20/61-33ccb
20/61-33cca
2040
1824
Address
Goldring Ave.
Goldring Ave.
Depth Cased Perforated Date
(feet) (feet) from - to sampled
425 10-11-72
400 400 270 - 400 10-11-72
Remarks*
Original; previously sampled in
mid 1940' s (MJ)
Substitute for 21/61/33ccal
(MJ),
400' TD, sampled in mid 1940 's,
original well unperforated
LG074
LG075
LG076
LG077
LG078
LG079
20/61- 34bcb
21/61- Ibba
21/62-29ccc
21/61-24aad
21/61-24aad
21/61-25cac
Union Pacific R.R. -
Well #157
2500 Boulder Hwy.
4200
3340
3360
5326
E. Russell Rd.
Rochelle Ave.
Rochelle Ave.
Topaz St .
780 757 280 - 290 10-12-72
590 - 594
400 200 10-12-72
404 10-12-72
160 160 60 - 160 10-13-72
100 100 10-13-72
10-13-72
Original; sampled 06-14-41
04-11-63 (DM)
Substitute for 20/61/35ddc2
418' TD sampled 09-14-45
Original; sampled 07-13-42
flows 0.005 cfs
Original; sampled 01-29-68
Original; sampled 01-29-68
Substitute for 21/61/25cabl
(MJ) ,
(MJ) ,
(MJ),
(DRI)
(DRI)
(DM),
sampled 01-20-47 (MB) , 02-23-63
(DM)
LG080
LG081
LG082
22/61- 3dda
22/61- Idac
21/62- 30dbb
7117
7044
5374
Paradise Rd.
Tomiyasu La.
Sandhill Rd.
335 None 10-13-72
209 10-13-72
390 10-17-72
Original; sampled 06-15-45
Original; sampled 09-08-30
07-13-42 (MJ) , 1962-3 (DM) ,
artesian
Original; sampled 08-04-42
(MJ)
(HM),
(MJ)
and 06-04-63 (DM)
10-20-72 Sampled to determine shallow
water quality in an area
reported to contain very high
TDS
Appendix 5 (continued)
-------
Well
#
Location
T R S
Address
Depth Cased Perforated
(feet) (feet) from - to
Date
sampled
Remarks*
NJ
O
00
LG084
LG112
LG113
LG114
LG115
LG116
LG117
21/62-31acc
20/60-24aaa
19/60-23bbc
19/60-27aab
20/62-19cab
20/62-19bbb
20/61-13adb
6100 S. Pearl St.
4200 Smoke Ranch Rd. -
Well #2
7000 Gilcrease Rd.
Ranch House Rd. &
Tonopah Hwy.
3725 E. Lake Mead Blvd.
2342 N. Pecos Blvd.
2934 L.V. Blvd. No.
LG118 20/62- 4add Nellis AFB - Well #1
LG119 20/61- 4add 4434 Craig Rd.
LG120 22/61-12bbb 2465 Warm Springs Rd.
LG121 20/61-19dda 800 Tonopah Hwy.
600
312 312 212 - 312
560
605
200 200
289 289
300 300
800 800
900 900
None
60 - 300
90 - 784
295 295 275 - 290
10-20-72 Original; sampled 07-13-42 (MJ)
06-08-73 Substitute for 20/60/24adb (MJ),
385' TD, sampled 09-14-12 (C),
10-16-30 (HM)
06-08-73 Original; sampled 10-25-44 (MJ),
03-15-63 (DM)
06-08-73 Original; sampled 10-23-44 (MJ),
1963 (DM)
06-08-73 Substitute for 20/62/19cabl (MJ),
sampled 12-17-45 (MJ)
06-08-73 Original; sampled 12-17-45 (MJ)
06-08-73 Original; sampled 01-31-68 (DRI);
500r TD and 300'-500' perforated
interval reported in 1968;
driller's log indicates 300' TD
and perforated 60'-300'
06-08-73 Original; sampled 05-05-41 (MJ),
10-17-56 (DM)
06-12-73 Substitute for 20/61/4addl (HM),
850' TD
06-12-73 Possible original; believed
equivalent to 20/61/12bbl (MJ),
sampled 10-17-44 (MJ) 06-20-63
(DM)
06-08-73 Substitute for 20/61/19ddcl(MJ),
280' TD
Appendix 5 (continued)
-------
to
o
VD
Well
#
LG122
LG123
LG124
LG125
LG127
Location
T R S
Address
DepthCasedPerforated
(feet) (feet) from - to
Date
sampled
Remarks*
20/61-33cca
20/61-35cbb
21/61- 4dac
21/61- 4dac
716 Shadow Ln.
1201 Fremont St.
Michelas Water Co.
244 St. Louis Well #1
Michelas Water Co.
244 W. St. Louis Ave.
Well 12
LG126 20/61-18bcc 2772 Tonopah Hwy.
20/61-29cbc
3333 W. Washington Ave.
226
460
650
810
500 500 300 - 500
600
06-08-73 Possible original; believed
equivalent to 20/61/33oca2 (MJ),
226' TD, sampled 02-21-38 (MJ)
06-08-73 Original; sampled 09-14-45 (MJ),
12-19-62 (DM)
06-11-73 Original; sampled 10-25-44 (MJ),
04-16-63 (DM)
06-11-73 Original; sampled 05-19-41 (MJ),
04-16-63 (DM)
06-08-73 Substitute for 20/61/18bcc (MJ),
412' TD, sampled 02-16-45 (MJ),
11-26-62 (DM)
06-08-73 Original; sampled 02-05-32 (HM)
*"Original" signifies a resampling in 1972 or 1973 or the same well sampled previously. "Substitute" indicates
that the original well could not be located or was destroyed and that another well having the location and
characteristics shown was used as a replacement. Previous sampling dates are shown, followed by initials to
indicate the following data sources: DM Domenico and Maxey (1964)
DRI Desert Research Institute
HM Hardman and Miller (1934)
MJ Maxey and Jameson (1948)
-------
Appendix 6. Tritium Sampling Points and Analytical Results
210
-------
(O
Station*
LW002
007
009
Oil
012
015
015
020
022
027
030
032
033
034
034
034
048
049
057
058
059
Location
21/62-,23bdb
21/63-14daa
21/61-13aba
21/62-29dcd
21/62-29dbb
22/62-04bcc
22/62-:04bcc
21/62-36cdd
22/63-07bca
21/62-22bbd
21/53-.28adb
21/63- 32bcd
21/62- 22ddb
21/62-10cdd
21/62-lOcdd
21/62- lOcdd
21/63-31bba
21/63- 31bbb
17/59- 34aab
22/58- 02cob
21/62-19aaa
DRI
Sample
No.
574
550
601
554
556
555
608
576
573
553
583
557
1881
605
607
552
572
575
578
581
582
Sample
Date
May- June
1971
06-03-71
06-21-71
06-11-71
05-31-71
05-31-71
05-31-71
May-June
1971
May-June
1971
05-27-71
05-31-71
05-31-71
01-16-73
06-29-71
06-29-71
05-27-71
May-June
1971
May- June
1971
06-14-71
06-15-71
06-15-71 '
Assay
Date
09-30-71
09-30-71
09-30-71
09-30-71
09-30-71
09-30-71
11-15-71
09-30-71
09-30-71
09-30-71
09-30-71
09-30-71
04-23-73
09-30-71
09-30-71
09-30-71
09-30-71
09-30-71
09-30-71
09-30-71
Tritium
Concentra-
tion (TU)t
42
42
173
21
21
5
2
28
29
29
385
360
194
349
411
11
76
75
69
66
17
329
358
4
20
40
.6
.1
.9
.7
.5
.9
.7
.2
.9
.7
.0
.2
.9
.8
.4
j-
.8
.5
.6
+ 2.
+ 1.
+10
+ 1.
+ 1.
+ 0.
+ 0.
+ 3.
+ 1.
+ 1.
+14
+14
+10
+18
+14
± °-
+ 3.
+ 3.
+ 4.
+ 2.
+ 0.
+13
+14
+ 0.
+ 0.
+ 2.
2
7
5
4
4
3
3
2
2
5
8
0
2
8
8
3
9
1
Method
of ,
Analysis+ Remarks
ES
EG
GC
ES
EG
EG
EG
ES
EG
1
GC
GC
GC
ES
GC
EG
ES
EG
ES
EG
EG
GC
GC
EG
EG
ES
Las Vegas Wash flow, primarily sewage
Las Vegas Wash, total flow from all sources
Flamingo Wash, spring flow
Seepage north of Whitney Mesa
Grapevine Spring
Seepage from underdrain beneath Sunset Rd .
Check sample
Ground water return flow from BMI complex
3MI waste discharge to upper tailings ponds
Clark County STP outflow
Pond adjacent to Las Vegas Wash near bedrock
constriction
Ground water return flow from BMI tailings
ponds
Shallow ground water at extreme east end of
Tropicana Avenue
Las Vegas STP outflow
Las Vegas STP outflow; check sample
Las Vegas STP outflow
Ground-water return flow from lower (BMI)
ings ponds
t
Corn Creek Spring
Bonnie Springs
Ground-water seepage from beneath Flamingo
Reservoir
tail
40.6 + I.I
EG
Appendix 6 (continued)
-------
to
Station*
LW060
OCO
061
061
OC2
034
035
oac
087
03d
089
090
091
092
094
095
096
097
IAJ002
006
OU7
Location
21/61-12dac
21/61-12dac
21/62-10cdb
21/62-10cdb
21/62-22bbb
21/61-14adb
20/61-26c.-dc
20/61-26cba
21/61-02aaa
21/61-01Uaa
20/61-34acu
21/61-'10cca
21/61-20aad
21/61-09aaa
21/61-14bbc
20/61-22dba
20/51-27cac
20/61-31aac
22/62-Olcba
.21/63-.28aca
21/63-28aca
DRI
Sample
No.
602
603
604
606
609
1908
1874
1375
1876
1877
1379
1883
1884
1885
1888
1889
1891
551
580
565
570
Sample
Date
06-29-71
06-29-71
06-29-71
06-29-71
06-29-71
01-28-73
01-15-73
01-15-73
01-15-73
01-15-73
01-16-73
01-18-73
01-18-73
01-18-73
01-24-73
01-28-73
01-28-73
05-28-71
05-31-71
06-07-71
06-08-71
Assay
Date
09-30-71
11-15-71
09-30-71
11-15-71
09-30-71
04-23-73
04-23-73
04-23-73
04-23-73
04-23-73
04-23-73
04-23-73
04-23-73
04-23-73
04-23-73
04-23-73
04-23-73
09-30-71
09-30-71
09-30-71
09-30-71
Tritium Method
Concentra- of ,
tion (TU) t Analysis? Remarks
23
23
26
68
73
205
35
22
13
98
41
125
25
188
21
91
9
38
3
4
301
250
246
.7
.8
.0
.6
.6
.6
.3
.9
.1
.4
.1
.8
.5
.3
.3
.5
+ 1
+ 1
+ 1
+ 3
+ 3
+12
+ 1
+ 0
± °
+ 4
+ 1
+ 5
+ 1
+ 7
+ 1
± 3
+ 0
+ 1
± °
+ 0
+15
+10
+13
.7
.0
.3
.6
.9
.6
.0
.6
.0
.0
.6
.5
.7
.3
.3
ES
EG
1
ES
1
GC
EG
EG
EG
EG
EG
EG
EG
EG
EG
EG
EG
EG
EG
EG
ES
EG
EE
Spring discharge into Flamingo Wash
11
Las Vegas STP inflow
11
Clark Co. STP inflow
Shallow ground-water discharge from a tile
field beneath golf course
Shallow ground-water discharge from an under-
drain beneath 15th St.
Shallow ground-water discharge from an under-
drain beneath Maryland Pkwy. at Harris St.
Shallow ground-water discharge from an under-
drain beneath Eastern Ave. at Ballard Dr.
Shallow ground-water being pumped from under-
drain below Montgomery Wards Dept. store
Shallow ground water beneath El Cortez park-
ing lot
Shallow ground-water discharge from underdrain
beneath Convention Center
Shallow ground water pumped from elevator
shaft pit of Dunes Hotel
Shallow ground water beneath Sahara Hotel
Shallow ground water pumped from basement of
Sears Roebuck Dept. store
Shallow ground-water discharge from an under-
drain at Lake Mead Blvd. and 1-15
Shallow ground-water seepage from underdrains
beneath UPRR trestle at Bonanza Rd.
Composite sample from LWWD deep wells in main
well field
Deep artesian well
Piezometer (41 feet TD) adjacent to L.V. Wash
Piezometer (134 feet TD) adjacent to L.V. Wash
Appendix 6 (continued)
-------
w
Station*
LG013
017
019
o; B
027
029
033
035
041
042
043
044
047
048
050
Location
22/63-05cbb
21/63-31abb
21/63-31bab
21/63-07bcb
21/62-36baa
21/62-26dba
21/62-26dba
21/62-15dda
20/62-32aba
20/62-32aba
21/62-29dcd
21/62-.29dcd
20/61-36ddd
20/61~36ddd
21/62-35dda
DRI
SampJ e
NO.
558
1747
568
566
571
563
559
546
549
564
569
548
567
561
579
Sample
Date
06-08-71
11-01-72
06-10-71
06-03-71
06-09-71
06-10-71
06-09-71
06-10-71
06-09-71
06-09-71
06-11-71
06-11-71
06-09-71
06-09-71
May-June
1971
Assay
Date
09-30-71
04-23-73
09-30-71
09-30-71
09-30-71
09-30-71
09-30-71
09-30-71
09-30-71
09-30-71
09-30-71
09-30-71
09-30-71
09-30-71
09-30-71
Tritium
Concentra-
tion (TU)t
285
287
6
4
4
320
320
3
58
57
5
4
3
2
5
3
4
212
.5
.8
.7
.0
.1
.2
.4
.2
.9
.9
.3
.4
.2
+12
+15
+ 0
± °
± °
+13
+16
± °
+ 2
+ 2
± °
+ 0
+ 0
+ 0
± °
± °
+ 0
± 9
.3
.4
.3
.3
.9
.3
.3
.3
.3
.3
.3
.3
.3
Method
of t
Analysis'! Remarks
EG
ES
EG
EG
EG
EG
ES
EG
ES
EG
EG
EG
EG
EG
EG
EG
EG
EG
Piezometer (241 feet TD) in BMI (upper) tailings
ponds
Piezometer (84 feet TD) adjacent to L. V. Wash
Artesian well (70 feet TD) (piezometer) between
lower tailings ponds and L.V. Wash; dis-
charge from Muddy Ck. Fm
Piezometer (101 feet TD) below effluent ditch
leading to upper tailings ponds
Piezometer (62 feet TD) on western side of
lower tailings ponds
Artesian well (97 feet TD) ; discharge from
Muddy Ck. Fm.
Piezometer (30 feet TD) completed in shallow
sand and gravel deposits overlying the
Muddy Ck. Fm.
Piezometer (102 feet TD) in flood plain of
L.V. Wash below treatment plants and irri-
gated area
Piezometer (67 feet TD) in flood plain of L.V.
Wash and above treatment plants
Piezometer (168 feet TD) in flood plain of
L.V. Wash and above treatment plant
Piezometer (56 feet TD) at north end of Whitney Mesa
Piezometer (129 feet TD) at north end of Whitney
Mesa
Piezometer (97 feet TD) on west side of scarp
crossing E. Charleston Blvd.
Piezometer (48 feet TD) at same location as LG047
Shallow ground water 2.3 miles north of BMI
complex
Appendix 6 (continued)
215
+11
ES
-------
to
Station*
LG055
056
057
058
059
061
093
098
099
100
101
102
103
104
105
107
108
110
115
128
128
129
130
131
Appendix 6
Location
21/63-29ccb
21/62-llbcb
20/61-03dab
20/61-15dcc
20/61-29ccc
19/60-04cda
21/62-30bda
21/62-08dcc
21/62-09abb
20/61-35add
21/62-21cad
21/61-02bac
21/61-Oldcd
21/61-13bbc
21/61-:23dab
21/61-26ccb
21/61-08acd
20/61-33cdb
20/62-19cab
21/62-15ccb
21/62-15ccb
20/61-30ddb
21/62-08aad
19/60-23add
(continued)
DRI
Sample
No.
547
562
585
584
560
577
1887
2024
2025
2023
2027
2022
2021
2029
2030
2031
2028
2230
1704
2026
2026
1924
2224
2161
Sample
Date
06-11-71
06-14-71
06-15-71
06-15-71
05-28-71
06-14-71
01-10-73
04-11-73
04-11-73
04-11-73
04-11-73
04-11-73
04-11-73
04-11-73
04-11-73
04-11-73
04-11-73
08-20-73
10-05-72
04-11-73
04-11-73
01-28-73
08-02-73
07-31-73
Assay
Date
09-30-71
09-30-71
09-30-71
09-30-71
09-30-71
09-30-71
04-23-73
06-14-73
06-14-73
06-14-73
06-14-73
06.-14-73
06-14-73
06-14-73
06-14-73
06-14-73
06-14-73
10-21-73
06-14-73
~ 06-14-73
06-14-73
06-14-73
10-21-73
10-21-73
Tritium
Concentra-
tion (TU)t
407
6
4
4
4
5
2
17
24
30
166
53
45
40
79
36
16
16
6
107
100
38
55
5
.0
.5
.1
.3
.1
.0
.0
.7
.9
.0
.0
.1
.1
.0
.4
.3
.4
.8
.9
.8
.5
.1
+13
+ 0
+ 0
+ 0
+ 0
+ 0
•f 0
± °
+ 1
+ 1
± 7
+ 2
+ 1
+ 1
+ 3
+ 1
+ 0
+ 0
+ 0
± 4
+ 4
± 1
+ 2
± °
.4
.4
.3
.3
.3
.3
.8
.1
.3
.1
.8
.6
.2
.4
.8
.7
.4
.3
.1
.6
.2
.3
Method
of
Analysis?
GC
EG
EG
EG
EG
EG
EG
EG
EG
EG
EG
EG
EG
EG
EG
EG
EG
EG
EG
EG
EG
EG
EG
EG
Remarks
Shallow ground-water tributary to L.V. Wash
in the vicinity of the BMI tailings ponds
Beep ground water adjacent to L.V. Wash
Nell is AFB Well #2
City of No. Las Vegas Losee Well
LWWD Well #34
Well at Tule Springs
Artesian well in Paradise Valley
Shallow ground water adjacent to residential
development using Colorado River water
Shallow ground water below Winterwood Golf
Course
Shallow ground water adjacent to an older
residential development
Shallow ground water adjacent to residential
area served by Colorado River water
Shallow ground water
Shallow ground water occurring in a zone of
high permeability; possibly a buried wash
Shallow ground water adjacent to a residential
area served by Colorado River water
ii
"
Shallow ground water beneath an old residential
development served by local ground water
Domestic well (200 feet TD)
Dewatering well (35 feet TD) in LDS Church farm
area; fields irrigated with sewage
"; check sample
Shallow ground water adjacent to a residential
area served by deep ground water from LWWD
Domestic well (90 feet TD) adjacent to Flamingo
Wash
Well (400 feet TD) adjacent to Gilcrease Ranch
-------
Station*
LG132
LM213
LM214
LM215
Location
20/60-19dca
21/64-19ada
21/64-19ada
22/64- 03acd
DRI
Sample
No.
2149
586
587
588
Sample
Date
07-18-73
06-17-71
06-17-71
06-17-71
Assay
Date
10-21-73
09-30-71
09-30-71
09-30-71
Tritium
Concentra-
tion (TU)t
9.7
333
321
372
+ 0.5
+13
+12
+13
Method
of .,
Analysist Remarks
EG
GC
GC
GC
Very shallow ground water in an old
tial area served by local ground
septic tank disposal systems
Lake Mead
Lake Mead
Lake Mead
re si den -
water and
* More complete sampling point descriptions are presented in Appendix 2.
IS
t Tritium concentrations are expressed in tritium units (TU) , One TU equals 1 H3 atom in 1 x 10 H,, atoms.
' 1 The following analytical methods were utilized by Teledyne Isotopes, Inc., Westwood, New Jersey:
to ES Enrichment + liquid scintillation
EG Enrichment + gas counting
GC Direct gas counting without enrichment
1 Unspecified method of analysis made on certain check samples submitted to Dr. Gote Ostlund, School
of Marine and Atmospheric Science, University of Miami, Miami, Florida
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TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
1. REPORT NO.
EPA-600/2-78-179
2.
3. RECIPIENT'S ACCESSION-NO.
4. TITLE AND SUBTITLE
5. REPORT DATE
Land and Water Use Effects on Ground-Water
Quality In Las Vegas Valley
August 1978 issuing date
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
Robert F. Kaufmann
8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Desert Research Institute
Las Vegas, Nevada 89109
10. PROGRAM ELEMENT NO.
1CC614
11. CONTRACT/GRANT NO.
R-800946
12. SPONSORING AGENCY NAME AND ADDRESS
Robert S. Kerr Environmental Research Laboratoty
Office of Research and Development
U.S. Environmental Protection Agency
Ada, Oklahoma 74820
13. TYPE OF REPORT AND PERIOD COVERED
Final; 11/1/69 - 1/51/74
14. SPONSORING AGENCY CODE
EPA/600/15
15. SUPPLEMENTARY NOTES
Project Officer: Fredric Hoffman, Region IX, San Francisco, CA 94111
16. ABSTRACT
The hydrogeologic study of the shallow ground-water zone in Las Vegas
Valley, Nevada determined the sources and extent of ground-water contamina-
tion to develop management alternatives and minimize adverse effects. An
extensive, computerized data base utilizing water analyses, well logs, head
measurements, and surface flows was developed. Flow system analysis, gross
chemical data and tritium analyses were used in combination with trend
surface techniques to ascertain natural and contaminated ground-water quality
to depths of 6 to 50, 51 to 100, and 101 to 300 feet. At depths below 100
feet, the distribution of all constituents reflects natural controls.
Nitrate and chloride in the zone from 0 to 50 feet are closely related to
waste disposal activities, chief of which are industrial effluent, treated
sewage, and septic tanks. In addition, tritium is highly indicative of
return flows associated with distribution of Colorado River water in the
Valley. Localized contamination of shallow unconfined ground water and
rapid appearance of return flows is accentuated by pronounced vertical
hydraulic and stratigraphic boundary conditions present in the eastern and
western parts of the Valley. Nonparametric testing of extremely limited
historical water quality data to ascertain temporal changes, particularly
for the very shallow aquifers, yielded generally insignificant results.
7.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.lDENTIFIERS/OPEN ENDED TERMS
c. COSATI Field/Group
Ground water
Water pollution
Water use
Las Vegas Valley
13/B
8. DISTRIBUTION STATEMENT
Release to Public
19. SECURITY CLASS (ThisReport)
unclassified
21.
PAGES
20. SECURITY CLASS (Thispage)
unclassified
22. PRICE
EPA Form 2220-1 (9-73)
216
* U.S. GOVHNMENTPRIimitG OFFICE: 1978- 757-140/1453
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