£EPA
United States Environmental Monitoring
Environmental Protection and Support Laboratory
Agency P.O. Box 15027
Las Vegas NV 89114
EPA-600/7-79-235
November 1979
Research and Development
Assessment of Energy
Resource Development
Impact on Water
Quality:
The San Juan Basin
Interagency
Energy-Environment
Research
and Development
Program Report
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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 categories
were established to facilitate further development and application of environmental
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 INTERAGENCY ENERGY—ENVIRONMENT
RESEARCH AND DEVELOPMENT series. Reports in this series result from the effort
funded under the 17-agency Federal Energy/Environment Research and Development
Program. These studies relate to EPA'S mission to protect the public health and welfare
from adverse effects of pollutants associated with energy systems. The goal of the Pro-
gram is to assure the rapid development of domestic energy supplies in an environ-
mentally-compatible manner by providing the necessary environmental data and
control technology. Investigations include analyses of the transport of energy-related
pollutants and their health and ecological effects; assessments of, and development of,
control technologies for energy systems; and integrated assessments of a wide range
of energy-related environmental issues.
This document is available to the public through the National Technical Information
Service, Springfield, Virginia 22161
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EPA-600/7-79-235
November 1979
ASSESSMENT OF ENERGY RESOURCE DEVELOPMENT IMPACT
ON WATER QUALITY
The San Juan River Basin
S. M. Melancon, T. S. Michaud, and R. W. Thomas
Monitoring Operations Division
Environmental Monitoring and Support Laboratory
Las Vegas, Nevada 89114
ENVIRONMENTAL MONITORING AND SUPPORT LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
LAS VEGAS, NEVADA 89114
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DISCLAIMER
This report has been reviewed by the Environmental Monitoring and
Support Laboratory, U.S. Environmental Protection Agency, and approved for
publication. Mention of trade names or commercial products does not
constitute endorsement or recommendation for use.
ii
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FOREWORD
Protection of the environment requires effective regulatory actions that
are based on sound technical and scientific data. This information must
include the quantitative description and linking of pollutant sources,
transport mechanisms, interactions, and resulting effects on man and his
environment. Because of the complexities involved, assessment of specific
pollutants in the environment requires a total systems approach that
transcends the media of air, water, and land. The Environmental Monitoring
and Support Laboratory-Las Vegas contributes to the formation and enhancement
of a sound monitoring data base for exposure assessment through programs
designed to:
• develop and optimize systems and strategies for monitoring
pollutants and their impact on the environment, and
• demonstrate new monitoring systems and technologies by applying
them to fulfill special monitoring needs of the Agency's
operating programs.
This report presents an evaluation of surface water quality in the San
Juan River Basin and discusses the impact of energy development upon water
quality and water availability. The water quality data collected to date and
presented in this report may be considered baseline in nature and used to
evaluate future impacts on water quality. This report was written for use by
Federal, State, and local government agencies concerned with energy resource
development and its impact on western water quality. Private industry and
individuals concerned with the quality of western rivers may also find the
document useful. This is one of a series of reports funded by the Interagency
Energy-Environment Research and Development Program. For further information
contact the Water and Land Quality Branch, Monitoring Operations Division.
George B. Morgan
Director
Environmental Monitoring and Support Laboratory
Las Vegas, Nevada
111
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ABSTRACT
The San Juan River Basin is a key area in the search for untapped
resources to supplement our rapidly increasing energy requirements and reduce
our dependency upon foreign fuels. Vast beds of low-sulfur, strippable coal
supply fuel to two electrical generating plants in the basin, one of which,
the Four Corners plant, is one of the largest coal-fired electrical generating
facilities in the world. Extensive oil and gas fields cross the basin, and
two gasification complexes have been proposed for construction. Uranium
exploration is ongoing in the southern and western portions of the drainage
area. Energy development in the basin will provide a boost to the economy and
employment sectors of this area, as well as increase energy productivity,
which already handles electrical generating needs of over 1.5 million people
in communities as far removed as Los Angeles.
However, development of these energy resources, combined with numerous
irrigation projects, is expected to have considerable impact on water
resources in the San Juan River Basin. It appears unlikely that there are
sufficient surface or ground-water supplies to continue to meet projected
needs in the area, and stretches of the San Juan River are likely to become
dry during low-water years after all authorized diversions are active.
Decreased flows will accompany increased salt and sediment loadings from
energy developments. The result will be lower water quality, reducing water
usability for municipal, industrial, and irrigation purposes and having
adverse impacts on the aquatic ecosystem. A recommitment of water, presently
allocated to other users, will probably be necessary to assure maintenance of
minimum flow in the river and to preserve the regional aquatic and terrestrial
habitats. The existing network of U.S. Geological Survey, Colorado State
Health Department, and other State agencies' sampling stations is adequate
and, in order to assess the impact of energy development, should be carefully
monitored on a regular basis in the future. Priority listings of parameters
to be measured to detect changes in water quality parameters as a result of
energy resource development and to assess future projects are recommended.
IV
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CONTENTS
Foreword iii
Abstract iv
Figures vi
Tables vii
1. Introduction 1
2. Conclusions 3
3. Recommendations 5
4. Study Area 7
Physical description of basin 7
Water resources 11
Population and economy 17
Water uses 19
Fish and wildlife resources 19
Mineral resources 23
Land ownership and usage 23
5. Energy Resource Development 26
Active development 26
Future development 34
6. Other Sources of Pollution 42
Erosion 42
Mine drainage 42
Urban runoff 43
7. Water Requirements 44
Water rights 44
Water availability 45
San Juan River withdrawals 47
Import of water. 55
Water availability vs. demand 57
8. Water Quality 60
Sources of data 60
Summary of physical and chemical data 60
Impact of development on surface water 65
Impact of development on ground water 91
9. Assessment of Energy Resource Development 95
Impact on water quantity 95
Impact on water quality 97
10. Recommended Water Quality Monitoring Parameters 99
Physical and chemical parameters 99
Biological parameters 106
11. Assessment of Existing Monitoring Network 115
References 121
Appendices
A. Conversion factors 128
B. Chemical and physical data 130
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FIGURES
Number
1
2
3
4
5
6
7
8
9
10
11
12
Location of the San Juan River Basin
Distribution of various employment sectors in the San Juan
River Basin
Land ownership and usage in the San Juan River Basin
Location of oil and gas fields in the San Juan River Basin . . .
Location of coal mines, powerplants, and gasification sites
Mean annual discharge in the San Juan River at Bluff
Reconstructed streamflow at Lees Ferry based on tree-ring
analyses
Location of U.S. Geological Survey sampling stations in the
San Juan River Basin
Location of Colorado State Health Department sampling stations
in the San Juan River Basin
Distribution of major cations and anions at selected stations
in the San Juan River Basin, 1975
Mean total dissolved solids and conductivity, 1973, at U.S.
Page
8
10
18
24
27
29
47
58
62
64
66
Geological Survey sampling stations in the San Juan River
Basin 71
13 Mean calcium, sodium, magnesium, and potassium concentrations,
1973, at U.S. Geological Survey sampling stations in the
San Juan River Basin 72
14 Mean bicarbonate, sulfate, and chloride concentrations, 1973,
at U.S. Geological Survey sampling stations in the San Juan
River Basin 73
VI
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TABLES
Number Page
1 Summary of Total Projected Annual Energy Production Levels
from Advanced Sources 2
2 Generalized Geological Stratigraphic Sequence in the San Juan
River Basin 12
3 Existing Reservoirs and Lakes by State in the San Juan River
Basin, 1972 14
4 Past and Projected Populations in the San Juan River Basin by
State 17
5 Water Uses of Various Perennial Streams in the San Juan
River Basin , 20
6 Fish Species Known to Occur in the San Juan River Basin .... 21
7 High Quality Trout Streams in the San Juan River Basin 22
8 Trace Element Concentrations in Morgan Lake and Morgan Lake
Discharge to Chaco Wash in 1973 33
9 Trace Element Composition of Various Coals and Mining
Discharges in the San Juan River Basin 35
10 Calculated Emission Rates From the Four Corners Powerplant,
1974 37
11 Major Trace Elements of Concern as Potential Pollutants from
Coal Gasification Facilities 40
12 Present and Projected Depletions of Water in the San Juan
River Basin 46
13 Summary of 1965 Municipal and Industrial Withdrawal Water
Requirements in the San Juan River Basin by System and Source. 51
14 Summary of Projected Municipal and Industrial Water
Requirements in the San Juan River Basin 52
15 Summary of 1965 Consumptive Water Use by Fish and Wildlife in
States of the Upper Colorado Region 53
16 Water Allocations from the Dolores Project 56
17 U.S. Geological Survey Sampling Stations in the San Juan River
Basin 61
18 Colorado State Health Department Sampling Stations in the
San Juan River Basin 63
19 Water and Dissolved Solids Discharge in the San Juan Basin ... 67
20 Annual Summary of Flow and Total Dissolved Solids Data,
1941-68, in the San Juan River near Archuleta, New Mexico. . . 69
21 Annual Summary of Flow and Total Dissolved Solids Data,
1941-68, in the San Juan River near Bluff, Utah 70
22 Mean Chemical Characteristics of Water, Spoil, and Overburden,
Navajo Mine, 1973 75
vii
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jjumber Page
23 Cumulative Impacts of Major Water Users on Total Dissolved
Solids in the San Juan River Basin 77
24 Salt Loadings Attributable to Various Sources Along the San
Juan River Between the River Headwaters and Shiprock,
1965-66 78
25 Water Quality Criteria Recommended by the National Academy of
Science 79
26 Sawyer's Classification of Water According to Hardness Content . 80
27 Total Dissolved Solids Hazard for Irrigation Water 81
28 Maximum Total Dissolved Solids Concentrations of Surface
Waters Recommended for Use as Sources for Industrial Water
Supplies 82
29 U.S. Environmental Protection Agency Drinking Water Regulations
for Selected Radionuclides 86
30 Maximum Daily Suspended Sediment Concentrations at Selected
U.S. Geological Survey Sampling Stations in the San Juan
River Basin 88
31 Water and Dissolved Solids Contributed by Ground Water to
Selected Streams in the San Juan River Basin, 1914-57 93
32 Priority I, Must Monitor Parameters for the Assessment of
Energy Development Impact on Water Quality in the San Juan
River Basin 101
33 Priority II, Parameters of Major Interest for the Assessment
of Energy Development Impact on Water Quality in the San
Juan River Basin 103
34 Priority III, Parameters of Minor Interest that Will Provide
Little Useful Data for the Assessment of Energy Development
Impact on Water Quality in the San Juan River Basin 104
35 Priority I Biological Parameters Recommended for Monitoring
Water Quality in the San Juan River Basin 109
36 Priority II Biological Parameters Recommended for Monitoring
Water Quality in the San Juan River Basin 112
37 Parameters Monitored by the Existing Sampling Network'in the
San Juan River Basin and their Average Frequency of
Measurement 117
38 U.S. Geological Survey Stations Recommended to have Highest
Sampling Priority in the San Juan River Basin for Monitoring
Energy Development 120
vi i i
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1. INTRODUCTION
This report is part of a multiagency project involving the U.S.
Environmental Protection Agency (EPA), U.S. Geological Survey (USGS), National
Oceanic and Atmospheric Administration (NOAA), and the National Aeronautics
and Space Administration (NASA) under various interagency agreements. The
objective of the program is to develop and maintain an effective water
monitoring network for energy development areas in the Western United States
to assess the impact of ongoing and anticipated energy development upon water
quality and quantity. In this report, known energy developments, both present
and planned, are defined, and available environmental baseline data in the San
Juan River Basin are examined. The adequacy of the existing environmental
monitoring network is also evaluated and monitoring strategies are
recommended.
Throughout the 1950's, the United States was effectively energy self-
sufficient, satisfying its needs with abundant reserves of domestic fuels such
as coal, oil, gas, and hydroelectric power. However, energy consumption has
been increasing during the past 10 years at an annual rate of 4 to 5 percent,
a per capita rate of consumption eight times that of the rest of the world
(U.S. Bureau of Reclamation, 1977c). The Federal Energy Administration (1974)
in its "Project Independence" report gives the following statistics:
• By 1973, imports of crude oil and petroleum products
accounted for 35 percent of total domestic consumption.
• Domestic coal production has not increased since 1943.
• Exploration for coal peaked in 1956, and domestic production of
crude oil has been declining since 1970.
• Since 1968, natural gas consumption in the continental United
States has been greater than discovery.
The United States now relies on oil for 46 percent of its energy needs,
while coal, our most abundant domestic fossil fuel, serves only 18 percent of
our total needs (U.S. Bureau of Reclamation, 1977c). In light of the fact
that we have only a few years remaining of proven oil and gas reserves, and to
reduce our vulnerable dependency upon foreign oil, the Federal government is
promoting the development of untapped national energy resources in
anticipation of upcoming energy requirements. Included among these resources
are the abundant western energy reserves. Over half of the Nation's potential
coal is located in the Western United States, as well as effectively all the
uranium, oil shale, and geothermal potential. Table 1 shows the projected
national annual production levels for some recently expanding energy sources
through the year 2000.
1
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TABLE 1. SUMMARY OF TOTAL PROJECTED ANNUAL ENERGY PRODUCTION LEVELS
FROM ADVANCED SOURCES (1015 joules per year)
1970 1975 1980 1985 1990 1995 2000
Source
Solar
Geothermal
Oil shale
Solid wastes
Total
0
1.8
0
0
1.8
0
14
0
10
24
0
72
610
55
737
400
180
2,000
300
2,880
2,500
360
2,700
950
6,510
4,000
720
3,400
3,000
11,120
12,000
1,400
4,000
10,000
27,400
U.S. demand 70,000 83,000 98,000 120,000 140,000 170,000 200,000
Percent of
U.S. demand
filled by
above sources 3xlO'3 3xlO~2 0.8 2 5 6 13
Source: Modified from Hughes et al. (1974).
In the San Juan River Basin, development will include increased strip
mining of coal with possible construction of associated coal gasification and
coal-fired powerplants, development of uranium reserves, and maximum
utilization of extensive natural gas and oil fields. It is difficult to
assess the extent and severity of degradation in environmental quality that
can be expected from this development. However, one of the biggest impacts
will undoubtedly result from competition for water resources created by
growing demands of municipal, industrial, agricultural, and reclamation
projects. Energy development, which requires large amounts of water during
extraction, transportation, and conversion of resources to a usable form, can
potentially place a severe strain on water quality in the basin.
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2. CONCLUSIONS
Based on materials presented in this report the following conclusions are
drawn:
1. Surface water availability in the San Juan Basin will limit future
growth and development patterns, including development of energy
resources. With all future authorized diversions operational, the
San Juan River will become dry during drought years for many miles
below Shiprock. This likelihood is further increased if the
anticipated return flow from the Navajo Indian Irrigation Project
to the San Juan River is not realized. Many native fish, some of
which are already on the threatened or endangered lists, occupy
this stretch of river. In order to assure maintenance of minimum
flow in the river and to preserve the regional aquatic and
terrestrial habitats, a recommitment of water presently allocated
to other users will be necessary. By the 1980's, it is expected
that insufficient water supplies will exist to satisfy anticipated
fishing and hunting demands in the San Juan Basin.
2. The present quality of surface water in the San Juan River and its
tributaries is generally good. However, as availability of water is
reduced with increasing regional development, water quality in the basin
below Farmington will become a problem. The water quality parameters most
likely affected by increased development in the Basin are salinity, toxic
substances, suspended sediments, nutrients, and flow.
3. Mercury concentrations in fish in Navajo Reservoir were among the highest
in the Southwest. Mercury-bearing sedimentary rock is probably the main
source of this element in the river system, but study is needed to
determine the extent of manmade mercury emission and its hazard to water
bodies in the Basin.
4. Point source discharge of pollutants from energy development sites will
not pose a problem to water quality in the Basin if discharge limitations
are enforced. Rather, nonpoint pollution from such sources as stack
emissions, airborne dust, and subsurface drainage will be the major
contributors. Regular monitoring for potential violations from energy
development operation sites is required. Potential is quite high for
deposition of coal dust on the bottom of the San Juan Arm of Lake Powell.
If this should occur, changes in the near-bottom environment could have
drastic and adverse impact on the ecology of this productive water body.
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5. Secondary development pollution impacts are likely to become the major
contributing problem to water quality in the San Juan River. Increases
in organic pollutants and TDS levels from urban runoff and hydraulic
modifications and pollution from the expanding use of water conditioners
are expected.
6. The impact of the Navajo Indian Irrigation Project will be more severe
than that from energy development alone. Consumptive water use, salt and
nutrient loading of return flow waters, increased erosion, and
agricultural by-product wastes from canneries could all be major impacts
associated with this program.
7. In addition to the long-term trends, an increased number of pollution
"episodes" (spills, etc.) are expected as a result of the increased
transport of energy products in the area and the likelihood of flood
runoffs from waste disposal, cooling system, or mining sites. These
brief, but massive, events could cause both short- and long-term
effects that would be disastrous to both the ecology and the economy
of the area.
8. Organic pollutants from coal gasification plants are of special concern
because of the lack of available data regarding both their nature and
quantity.
9. The present U.S. Geological Survey (USGS) and Colorado State Health
Department sampling network in the San Juan River Basin are
generally well-situated for monitoring the impact of energy
development in that area, although two additional station locations
have been proposed. Six U.S. Geological Survey sampling stations
have been selected as having the highest sampling priority in the
San Juan Basin for energy monitoring efforts. Presently, sampled
parameters vary greatly from station to station and in time and
frequency of collection. Priorities have been established for
selection of water quality parameters necessary to monitor impacts
from energy development in this Basin.
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3. RECOMMENDATIONS
1. An expansion in the number of parameters regularly monitored to assess
the impact of energy development on surface water quality in the San Juan
River Basin is recommended. In particular, most trace elements and
nutrients, which are presently collected only irregularly, should be
incorporated into a more standardized sampling program. Pesticides, oils
and greases, and organics such as phenols are other parameters that
should be made part of a regular, if occasional, monitoring effort.
Increased use of biological monitoring as a tool for measurement of
long-term water quality trends is recommended.
2. The following U.S. Geological Survey stations are recommended for the
highest sampling priority in the San Juan River Basin for monitoring
energy development impact on surface waters:
San Juan River at Archuleta, New Mexico
Animas River near Cedar Hill, New Mexico
San Juan River at Farmington, New Mexico
San Juan River at Shiprock, New Mexico
San Juan River near Bluff, Utah
Chaco Wash at its mouth, New Mexico
3. It is recommended that the present surface water monitoring network be
restructured. The San Juan River stations at Shiprock and Farmington
should be sampled on a weekly basis in order to permit meaningful trend
analyses. The four other priority stations should be monitored on a
monthly basis to provide spatial distribution data. Coordination between
the sampling efforts of the U.S. Geological Survey and Colorado State
Health Department is recommended so that both agencies synchronize
sampling schedules and parameters sampled to the extent possible.
4. The following water quality parameters are recommended for at least
monthly sampling at the six priority stations in order to assess energy
resource development impact in the San Juan River Basin:
Total alkalinity Flow Dissolved potassium
Total ammonia Total iron Total selenium
Total arsenic Total lead Dissolved sodium
Bicarbonate Dissolved magnesium Dissolved sulfate
Total boron Total manganese Suspended sediments
Total cadmium Total mercury Temperature
Dissolved calcium Total molybdenum Total dissolved solids (TDS)
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5.
hydrocarbons
pH
cyanide Total phosphorus
Further research to determine the nature and extent of pollu
discharges from proposed coal gasification and conversion site
1 <; rprnmmemrlaH Tk~,~~ ~-i - j_ •-i-. MIIU t-unver b i un i> IC6S
" S|?^iSsi-;?;iE?S;S:^3'-
.ct,»,ties located In the river below Shiprock du??ng1ow water years.
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4. STUDY AREA
PHYSICAL DESCRIPTION OF BASIN
Location and Size
The San Juan River is the second largest tributary of the Colorado River.
Rising on the west slope of the Continental Divide in the San Juan Mountains,
it runs westward through the Four Corners area of Arizona, Colorado,
New Mexico, and Utah into its junction with the Colorado River approximately
121 km west of Bluff, Utah. The basin (Figure 1) extends approximately
258 km to the north and south and 402 km east and west. Located entirely
within the Upper Colorado Region, the San Juan Basin drains 64,608 km^ and
encompasses portions of 18 counties in four States (U.S. Soil Conservation
Service et al., 1974).
Climate
Climate in the San Juan Basin is primarily influenced by two factors: wide
variations in topography and moisture supply. Higher elevations (above
3,000 m) in the basin are typically characterized by an alpine climate, with
plentiful rainfall and cool year-round temperatures (U.S. Soil Conservation
Service et al., 1974). Those elevations below 2,000 m have generally a desert
climate, with low annual precipitation, mild winters, and hot summers. The
highest point in the basin is Windom Peak, Colorado (4,293 m), and the lowest
at the confluence of the San Juan and Colorado Rivers (1,097 m above sea
level).
Distantly removed from any major sources of moisture, precipitation in the
basin is generally associated with Pacific Ocean air masses that move inland
from the west dropping large amounts of water as they are lifted over the
San Juan Mountains and Continental Divide (U.S. Soil Conservation Service
et al., 1974). Occasionally during the summer months, winds shift and
approach the basin from the Gulf of Mexico, passing over the deserts of Mexico
and Arizona and inducing a rain shadow effect in the area. As a result of low
humidity and frequent winds, evaporation rates are high, reaching as much as
250 cm/yr at the lower elevations (U.S. Bureau of Reclamation, 1976a).
Maximum rainfall usually occurs July through August, during which time the
basin receives nearly half its annual precipitation from intense summer
thunderstorms (U.S. Soil Conservation Service et al., 1974). These storms
often cover only a few square kilometers on a given day and typically result
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SAN JUAN RIVER BASIN
37*00'
00
10 0 10 20 Miles
0 K) 20 30 Klkvnrter*
\{»^ 4 X\N
V X of*
:^^_
\ N
|
Figure I. Location of the San Juan River Basin.
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in flash floods. Winter precipitation is generally in the form of snow with
most falling in the mountainous areas of the basin. June is the driest month
of the year (U.S. Soil Conservation Service et al., 1974).
Geology
The San Juan River Basin geology is largely controlled by five major
structural features (Figure 2) (Baltz et al., 1966; Baltz, 1967; Kelley, 1970;
Peirce et al., 1970). The San Juan Structural Basin occupies the central and
eastern portion of the river basin extending roughly from the Arizona-
New Mexico State line westward to the Continental Divide. The structural
basin is bounded on the southwest by the Defiance Uplift, which extends
westward to the Black Mesa Basin, on the east by the Nacimiento Uplift -
Archuleta Anticlinorium, on the north by the Needles Mountain Upwarp, and on
the northwest by the Monument Upwarp.
The oldest part of the San Juan River Basin is the high San Juan Mountains
formed by the Needles Mountain Upwarp (U.S. Soil Conservation Service et al.,
1974; Baltz, 1967). Here crystalline rocks of Precambrian age are exposed.
Where tertiary volcanics and other intrusives have disrupted these rocks,
important ore bodies exist (Burbank and Luedke, 1969). On the southern and
western flanks of the San Juan Mountains and in the adjacent La Plata
Mountains outcrops of Paleozoic age exist (U.S. Conservation Service et al.,
1974). These include quartzites, limestones, and shales overlain by red
arkosic sandstones and conglomerates.
Westward, across broad areas of the Monument Upwarp, are exposed the
scenic reddish sand and siltstone cliff and plateau formations of Mesozoic
age. Mesozoic rocks dominate the San Juan Basin both in extent and commercial
value. The several thousand meters of alternating sandstones, siltstones, and
shales include commercially valuable coal beds, numerous gas and oil fields,
and locally enriched uranium ores. The shale outcrops provide readily
erodible soils and high sediment-producing areas (U.S. Soil Conservation
Service et al., 1974).
Sedimentary rocks of early Cenozoic age occur in the center of the
San Juan Structural Basin and produce localized badlands with high erosion and
sediment yields (U.S. Soil Conservation Service et al., 1974). Cenozoic and
tertiary volcanics occur around the northern and eastern edges of the
structural basin and form most of the high peaks in the San Juan Mountains
(U.S. Soil Conservation Service et al., 1974; Burbank and Luedke, 1969).
Quaternary deposits, ranging from Pleistocene to Recent, are widespread.
In the mountains, recent sliding and slump features are found. Major valleys
of the San Juan and La Plata Mountains contain glacial moraines. Sand and
gravel alluvial deposits occur in the larger stream valleys and flood plains.
Wind-deposited sands and silts are widespread and cover large areas (U.S. Soil
Conservation Service et al., 1974; Burbank and Luedke, 1969).
Presently, commercial coal deposits are found associated with the Upper
Cretaceous deposits throughout the San Juan Structural Basin and in older
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37W
Juan Basin
Chaco Slope
1O Q 10 20 Mil«
1O O W 2O 3O Kitom»l«r»
37C00'
Figure 2. The geologic structure of the San Juan River Basin.
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Mesozoic sediments along the Monument Upwarp. Extensive oil fields have been
found throughout the basin, usually associated with the underlying Paleozoic
strata (Peirce et al., 1970).
The geology has also largely dictated the scenic grandeur of the area.
The thick Mesozoic reddish sand and siltstones have produced the impressive
"monuments" of Monument Valley, the cliffs of Mesa Verde, Chaco Wash, and
Lake Powell, and the flat plateaus upon which they rest. The regional
tectonics have resulted in the high mountains and alpine conditions and the
equally impressive entrenched meanders at the "Goosenecks of the San Juan."
A generalized stratigraphic sequence of San Juan River Basin geology is
presented in Table 2.
WATER RESOURCES
Lotic
The San Juan River originates in the high reaches of the San Juan
Mountains, along with its principal tributaries, the Nayajo, Piedra,
Los Pi ribs, and Animas Rivers. Annual precipitation varies widely throughout
the basin with elevation; average annual values range from approximately
15 cm/yr in the valley near Mexican Hat to 127 cm/yr in the upper San Juan
Mountains (U.S. Soil Conservation Service et al., 1974). Mountain snowpack
melt produces spring flooding and maintains flow in the major tributaries
throughout the summer months. A number of other tributaries, such as
Chinle Wash, Chaco Wash, Canyon Largo, and Montezuma Creek drain large areas
but flow only intermittently in response to summer flash floods, while
McElmo Creek, La Plata River, and others have very low annual flows and
contribute little to the sustained streamflow of the San Juan River. In this
basin, less than 20 percent of the drainage area contributes over 90 percent
of the annual surface water supply (U.S. Soil Conservation Service et al.,
1974).
Lentic
There are over 75 lakes and reservoirs (Table 3) located within the
San Juan River drainage area (U.S. Soil Conservation Service et al., 1974).
Most of these are small (under 0.40 km^ surface area) and exist primarily
for recreational and irrigation purposes. Three water bodies are of
particular interest: Navajo Reservoir (63.1 km^ at normal pool elevation),
created by the impoundment of the San Juan River a few miles upstream from
Archuleta; Morgan Lake, a 4.9 km^ cooling pond for the Four Corners
thermal-electric powerplant filled with water drawn out of the San Juan River;
and Lake Powell, a 653.2 km2 (at planned pool elevation) impoundment of the
Colorado River that receives all the San Juan River discharge.
Ground Water
Over 98 percent of the water used in the basin is derived from surface
flows, since there are only limited amounts of ground water available (U.S.
11
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TABLE 2. GENERALIZED GEOLOGICAL STRATIGRAPHIC SEQUENCE IN THE SAN JUAN RIVER BASIN
Eras
Periods
Epochs
Stratigraphic Unit
Cenozoic Tertiary Eocene
San Jose Fn.
Cuba Mesa
Tapicltos
Regina
Haves
Maroon and variegated shales
Varicolored clay shale and si Ustones with Imbedded sandstone
(present In southern two thirds of the structural basin)
Yellow-buff sandstone with red sandstone and shales
(northern third of structural basin)
Buff-yellow crossbedded sandstone
Paleocene
Animas Fm.
Unconformity in southern portion of basin
Nacimiento Fm. - Varicolored sandstones, clays, and shale with thin coal layers
Ojo Alamo Fm.
Unconformity
Mesozoic Cretaceous
Mesa Verde
Group
r\j
Kirtland Sh.
Frultland Fm.
Picture Cliffs Ss.
Chuska Ss.
Lewis Sh.
Pt. Lookout Ss.
Menefree Fm.
Cliff House Ss.
Mancos Sh.
Unconformity
Dakota Ss.
Burrow Canyon Fm.
Unconformity •
Jurassic
San Rafael
Group
Morrison Fm.
Bluff Ss.
Suwnersville Fm.
Entrada Fm.
Carmel Fm.
Unconformity
Triassic
- Light-gray-to-tan sandstone, buff in lower parts (New Mexico areas)
- Claystone, sandstone, and shales (Farmington area north and west)
Interbedded dark sandstone and shale layers
Interbedded dark sandstone, shale, and coal layers
Varicolored sandstone, siltstone, and shale beds
Massive gray-brown sandstone (western portion of basin)
Light-to-dark-gray fissije clay shales (eastern portion of basin)
Buff, gray, and tan sandstones*
Interbedded shale, sandstone, and coal
Gray, buff, and orange-brown sandstone
Platy calcareous dark-gray marine shale with some thick,
bedded sandstone in the lower part
Yellow-buff sandstone and siltstone with coal layers
(Restricted outcrops)
Varicolored claystone and siltstones interbedded with fine-
to-medium sandstone
Orange-gray sandstone (the Bluff and Summerville units
pitch to the east)
Brownish siltstone with thin beds of sandstone and limestone
Varicolored sandstone, siltstone, and claystone with some
limestone, massive reddish-brown-to-orange sandstone in the
basal part
Reddish interbedded limestone, shales, calcareous sandstones,
and gypsum
(The Carmel, Navajo, Kayenta, and Wingate have been removed in
the eastern part of the basin)
(Continued)
*Not differentiated in the eastern and southern portions of the basin.
-------
TABLE 2. (Continued)
Eras
Periods
Epochs
Stratigraphic Unit
Mesozoic Triassic
Glen
Canyon Group
Navajo Ss.
Kayenta Fm.
Wingate Ss.
Chinle Fm.
- Thick massive red-to-red-orange sandstone
- Purplish red sandstone with thin siltstone layers
- Massive reddish-brown-to-orange sandstones
- Variegated siltstone and mudstone with thin layers
and sandstone
of limestone
Unconformity
Moenkopi Fir..
Unconformity
Paleozoic Permian
Cutler
Fm.
Pennsylvanian
DeChelly Ss.
Organ Rock
Cedar Mesa
Hal galto
Rico Fm.
Hermosa Group
Unconformity
Mississippian
Devonian
Silurian
Ordovician
Cambrian
Archeozoic Precambrian
Redwall Ls.
Ouray Ls.
Elbert Fm.
McCraken Ss.
Aneth Fm.
Not represented
Not represented
Muav. Limestone
Bright angel Shale
Tapeats
Unconformity
Granite and Gneiss
Brown sandstone, siltstones, and mudstones with greenish white
gypsum layers
DeChelly sandstone and Morrison are missing in the
eastern half of the basin; Cedar Mesa Fm. pinches out by
Arizona-New Mexico State line
Pale red-brown sandstones
Red and red-orange interbedded siltstone, sandstone, and shales
Light-colored c'rossbedded sandstones
Red and red-brown thin beds of sandstone, siltstone, and mudstone
Red siltstone, interbedded gray siltstone and limestone (absent
in the eastern portions of the basin)
Light gray and tan limestones with black layers of shale and
thin layers of gypsum and dolomite: oil- and gas-producing
Gray and white thick limestones
Light green limestones and dolomites
Green and red sandy dolomites and thin shale layers
White, gray, and red sandstone
Dark-brown-to-black dolomites, limestones, and shales
Blue-gray thinly bedded limestone and shale
Green micaceous shale with layers of sandstone and limestone
Red sandstone and shales
Sources: Modified from Gordon (1961), Baltz et al. (1966), Baltz (1967), Lochman-Balk (1967),
Peirce et al. (1970), and Kaufman et al. (1976).
-------
TABLE 3. EXISTING RESERVOIRS AND LAKES BY STATE
IN THE SAN JUAN RIVER BASIN, 1972
Reservoir Name
Arizona
Many Farms Lake
Lower Rock Point
Marsh Pass
Round Rock Lake
Pinnacle Lake
Tsaile Lake
Wheatfields Lake
Colorado
Bauer Lake No. 1
Bauer Lake No. 2
Columbine Lake
Ducks West Lake
Electra Lake
Echo Creek Canyon
Emerald Lake
Hatcher Lake
Pastoris Lake
Red Mesa Lake
Sullenberger Lake
Stevens Lake
Totten Lake
Turner Lake
Weber Lake
Williams Creek Lake
Colorado
Jackson Gulch
Lemon Lake
Vallecito Lake
Andrews Lake
Capate Lake
Cataract Lake
Durango Hatchery
Drainage
Chinle Wash
Chinle Wash
Chinle Wash
Lukachukai Wash
Tsaile Creek
Chinle Wash
Mancos River
Mancos River
Animas River
Animas River
San Juan River
Los Pinbs River
Piedra River
Animas River
La Plata River
Peora River
Piedra River
Mancos River
Animas River
Mancos River
Piedra River
Mancos River
Florida River
Los Pinbs River
Animas River
Purpose*
I
I
I
I
I
F&W
F&W
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
F&W
F&W
F&W
F&W
Maximum
Surface
Area
(km?)
4.86
0.02
1.1
0.10
0.40
0.14
0.56
3.40
0.48
1.44
0.54
0.19
0.54
0.10
0.35
0.95
0.20
0.16
1.08
0.88
2.51
11.02
0.08
0.21
0.16
0.01
(Continued)
* F&W
M&I
fish and wildlife, I = irrigation,
municipal and industrial, R = recreation
14
-------
Table 3. (Continued)
Reservoir Name
Drainage
Purpose*
Maximum
Surface
Area
(km2)
Colorado
Haviland Lake
Henderson Lake
Lost Lake
Lite Mountain (3 res.)
City (Durango)
Bayfield Lake
Mancos Lake
4 Ponds
New Mexico
Black Lake
Chuska Lake
Deadman Lake
Dulce Lake
Juan's Lake
Long Lake
Lost Lake
Lower Mundo Reservoir
Morgan Lake
Whiskey Lake
Navajo Lake
Beeline (Farmington 3)
Farmington Lake
Aztec Lake
Bass Lake
Butler Lake
Borland Lake
Big Gap Lake
Bolack Lake
Captain Tom's Lake
Holmburg Lake
Jackson Lake
La Jara Lake
Little White Cone Lake
Mulholand Lake
Toadacheene Lake
Ferris Lake
Mancos River
Animas River
Los Pianos
Mancos River
Mancos River
Coyote Wash
Red Willow Cr.
Wheatfield Cr.
Dulce Canyon
Chaco Canyon
Red Willow Cr.
Coyote Wash
Mundo Canyon
San Juan River
Red Willow Cr.
San Juan River
Animas River
Animas River
Animas River
Captain Tom Wash
La Plata River
La Jara Canyon
Little Whiskey Cr.
F&W
F&W
F&W
F&W
M&I
M&I
M&I
M&I
I.R
M&I.R
M&I
M&I
M&I
M&I
R
R.M&I
R
R
I.R
R
R
R
R
R
R
R
0.28
0.04
0.04
0.02
0.40
0.02
0.12
0.04
0.34
0.63
0.40
0.42
0.16
1.42
0.18
0.26
4.86
1.01
63.13
0.81
0.04
0.01
0.02
0.04
0.03
0.06
0.14
0.40
0.01
0.28
0.23
0.16
0.02
0.04
0.04
(Continued)
15
-------
Table 3. (Continued)
Reservoir Name
Drainage
Purpose*
Maximum
Surface
Area
(km*)
New Mexico
Crowley Lake
Luna Lake
El Paso Lakes
Southern Naschitti
R
I, MM
0.08
0.12
0.02
0.01
Utah
Lower Castle Creek Lake
Cottonwood (35 res.)
Montezuma (9 res.)
F.S. Cottonwood Creek
Monticello Lake
Blanding (3 res.)
Castle Creek
Cottonwood Wash
Montezuma Creek
Cottonwood Creek
Montezuma Creek
Westwater Creek
I
I
I
I
M&I
M&I
0.40
0.03
0.36
Source: Modified from U.S. Soil Conservation Service et al. (1974).
Soil Conservation Service et al., 1974). Ground water occurs as a combination
of shallow and deep water systems. The shallow system includes water in
alluvium aquifers and in the fractured shales and sandstone aquifers, which
are exposed at the basin edges but occur in the central part of the area at
greater depths. Much of the ground water cannot be used because the rocks
containing the resource are impermeable and yield water very slowly (U.S. Soil
Conservation Service et al., 1974), making recovery in large amounts
economically impractical. Few rock formations in the area are capable of
yielding large quantities of water, and those that do often yield brackish
supplies. These brackish waters require extensive treatment prior to use.
Since recharge to both ground-water systems is limited, there are no
dependable subsurface supplies for long-term energy development such as exist
in the Northern Great Plains region. This factor will greatly affect energy
utilization of the area, including the type and extent of mining techniques
(U.S. Bureau of Reclamation, 1976a). Some shallow aquifers along the San Juan
River are regularly recharged with river water so that they yield good water
at a shallow depth; frequently, however, they do not do so at a deeper depth.
For these reasons, ground water in the San Juan Basin is used primarily for
rural household, livestock watering, and mineral processing purposes (U.S.
Bureau of Reclamation, 1976a).
16
-------
POPULATION AND ECONOMY
Population centers in the San Juan Basin are sparsely distributed and
generally contain fewer than 10,000 residents. Two exceptions to this are the
communities of Farmington, with a 1965 estimated population of 21,000, and
Durango, with approximately 11,200 (Upper Colorado Region State-Federal
Inter-Agency Group, 1971b).
The early economy of the San Juan Basin was based upon agricultural and
mining activities (U.S. Soil Conservation Service et al., 1974). Since the
1950's, however, population growth (Table 4) has accompanied an increasing
economic dependence on tourism and energy-related mining development. This is
reflected in a major shift of employment sectors in the basin (Figure 3).
Employment in agriculture and forestry decreased from 36 percent of total
employment to 8 percent between 1950 and 1965, while employment in mining,
transportation, and the utilities increased from 14 to 23 percent during the
same time (U.S. Soil Conservation Service et al., 1974). Trade and services,
reflecting increasing recreational demands, increased from 36 to 53 percent,
representing the greatest employment-sector growth in the basin.
In the past, the economy of the Upper Colorado Region generally was based
upon export of agricultural and mining products. Since there was little
processing of the product within the region, little water was required for
municipal and industrial activities. Thus, water availability is not
TABLE 4. PAST AND PROJECTED POPULATIONS IN THE SAN JUAN RIVER BASIN
BY STATE
State 1965 1980 2000 2020
Arizona
Colorado
New Mexico
Utah
29,100
37,725
46,600
15,300
41 ,700
47,500
65,000
22,000
52,300
63,300
95,000
31 ,300
64,300
90,700
125,000
44,800
TOTAL 128,725 176,200 241,900 324,800
Source: Modified from Upper Colorado Region State-Federal Inter-Agency
Group (1971b).
17
-------
1950
1965
1980
2000
TOTAL
POPULATION 61>63«
99,625
150,337
202,915
TOTAL
EMPLOYMENT
19,231
29,720
50,363
72,035
KEY
1. TRADE AND SERVICES
2. AGRICULTURE AND FORESTRY
3. MINING
4. TRANSPORTATION AND UTILITIES
5. CONSTRUCTION
6. MANUFACTURING
Figure 3. Distribution of various employment sectors in the San Juan River Basin,
(Does not include Arizona portion of the basin.)
Source: Modified from U.S. Soil Conservation Service et al. (1974).
-------
generally considered to have limited urban or industrial growth in the area
(Upper Colorado Region State-Federal Inter-Agency Group, 1971b). In the
future, however, lack of adequate water resources is likely to be a
significant growth-limiting factor in the San Juan Basin. Agriculture,
although decreasing in importance to the basin economy, continues to be a
major consumer of available water in the area; in 1965, agriculture accounted
for nearly 93 percent of the total basin consumption (U.S. Soil Conservation
Service et al., 1974).
WATER USES
The unspoiled areas of water acreage in the arid San Juan River Basin are
used to serve a variety of needs. Perennial streams in the Basin, as well as
Lake Powell, provide water for such uses as public water supplies, irrigation,
recreational activities (including fishing and swimming), industrial and
municipal plants, generation of electricity, and livestock watering (Table 5).
FISH AND WILDLIFE RESOURCES
Fish and wildlife are important to both the economy and environment of the
San Juan River Basin. Because of low population density and extensive areas
of public land, this region has escaped many of the pressures that have
displaced fish and wildlife habitats in some areas, and resources are
plentiful. Annually, large numbers of residents and visitors enjoy fishing,
hunting, and other nonconsumptive recreational water uses on the San Juan
River. In 1965, recreationists spent more than $18 million in the basin (U.S.
Soil Conservation Service et al., 1974)
Mule deer and elk are the primary game animals, with deer being found
throughout the basin in great abundance (U.S. Soil Conservation Service
et al., 1974). Other important game include the wild turkey, bighorn sheep,
black bear, and a variety of small animals and game birds.
Sport fishing has traditionally been restricted to streams and natural
lakes, but with present-day hydrological alterations, such as impoundments,
diversions for flood control or out-of-basin water usage, and irrigation,
fishing trends have been substantially modified. Much of the present-day
fishing is from reservoirs, since the available area of reservoir water in the
basin exceeds that of natural lakes and river systems.
Cutthroat trout (Salmo clarki) and mountain whitefish (Prosopium
williamsoni) are the only endemic game fish in the Upper Colorado River
drainage (Upper Colorado Region State-Federal Inter-Agency Group, 1971c). In
the San Juan Basin they have generally been replaced (Table 6) by introduced
fish species such as rainbow trout, which are better suited for propagation in
this area. Brook trout and brown trout have also been introduced to the
basin. There are still a number of tributaries in the San Juan Basin that are
high-quality trout streams in their upper reaches (Table 7). These streams
should be carefully considered in water development planning in the basin in
an attempt to preserve the outstanding fishing found there.
19
-------
TABLE 5. WATER USES OF VARIOUS PERENNIAL STREAMS IN THE SAN JUAN RIVER BASIN
Location
San Juan River
Source to Navajo Reservoir
Navajo Reservoir to Colorado-
New Mexico State line
Colorado-New Mexico State line
to Navajo Dam
Navajo Dam to Blanco
Public Harm Water
Water Supply Recreation Fishery
X X
X X
X X
X
Cold Hater
Fishery Industrial Irrigation
X
X
XXX
XXX
Livestock
Watering
Blanco to New Mexico-Colorado
State line
Colorado (at Four Corners)
Colorado-Utah State line to mouth
Pledra River
Source to Navajo Reservoir
An
-------
TABLE 6. FISH SPECIES KNOWN TO OCCUR IN THE SAN JUAN RIVER BASIN
Common Name
Scientific Name
Kokanee
Brown trout
Rainbow trout
Brook trout
Humpback sucker
Bluehead sucker
Flannelmouth sucker
White sucker
Carp
Speckled dace
Northern squawfish
Colorado squawfish
Roundtail chub
Fathead minnow
Blue catfish
Channel catfish
Yellow bullhead
Black bullhead
Mosquitofish
Largemouth bass
Black crappie
Green sunfish
Bluegill
Mottled sculpin
Oncorhynchus nerka
Salmo trutta
Salmo gairdneri
Salvelinus fontinalis
Xyrauchen texanus
Catostomus discobolus^
Catostomus latipinnis
Catostomus commersoni
Cyprinus carpio
Rhim'chthys osculus
Ptychocheilus oregonensis
Ptychocheilus lucius
Gil a robusta
Pimephales promelas
Ictalurus furcatus
Ictalurus punctatus
Ictalurus natal is
Ictalurus me!as
Gambusia affinis
Micropterus salmoides
Pomoxis m'gromaculatus
Lepomi s cyanel1 us
Lepomi s macrochirus
Cottus bairdi
Sources: Modified from U.S. Bureau of Reclamation (1975), Sublette (1976),
and U.S. Bureau of Indian Affairs (1976). Common and scientific
names of fishes are from Bailey et al. (1970).
21
-------
TABLE 7. HIGH QUALITY TROUT STREAMS IN THE SAN JUAN RIVER BASIN
River Segment
Navajo River Source to New Mexico State line
Piedra River Source to Navajo Reservoir
Los Pinbs River Source to Navajo Reservoir
Animas River Silverton to the mouth of Cascade Creek
San Juan River Navajo Dam to Blanco
Mancos River Source to Mesa Verde water intake
Florida River Source to State Highway 160 crossing
Source: Modified from Upper Colorado Region State-Federal
Inter-Agency Group (1971c).
Warm water fishes, such as the channel catfish, have been successfully
planted in the lower elevation streams and in some of the impoundments
(U.S. Soil Conservation Service et al., 1974). Largemouth bass have prospered
in some regions of warmer water and are now important game fish in Lakes
Navajo and Powell. Black crappie and bluegill have also been stocked in
reservoirs and farm ponds in the drainage (Upper Colorado Region State-Federal
Inter-Agency Group, 1971c). When first impounded, Morgan Lake, a cooling lake
for the Four Corners Powerplant, supported a trout fi,shery until plant
operations resulted in higher water temperatures than could be tolerated by
cold water fish (Blinn et al., 1976). A catfish, largemouth bass, and
bluegill fishery was established to replace the trout; however, in the summers
of 1973 and 74, major fish kills resulting from high temperatures and reduced
oxygen levels occurred, which virtually eradicated many of the existing
species (Blinn et al., 1976). A tropical fish (Tilapia sp.) was planted in
hope of establishing a fishery better adapted to the warm water habitat; this
stocking was not successful, and currently the only two abundant species found
in Morgan Lake are the carp and channel catfish, two of the most tolerant
fishes known (Blinn et al., 1976).
Below Navajo Dam, changes in fishery types can be followed and can be
broken into distinct sections of the San Juan River. From Navajo Dam to
13 km downstream, the river is cool, clear water flowing over a rubble
substrate. Considered an important rainbow and brown trout habitat, the river
water temperatures are consistently cool enough in the summer and warm
22
-------
enough in the winter to support year-round trout production and an abundant
macroinvertebrate population (Southwest Energy Study, 1972a). In the reach
13 to 29 km from the dam, the influences of Navajo Reservoir are lessened.
Numerous washes funnel sediments into the river resulting in a silt-laden
stream bottom and increased heat absorption. Trout and macroinvertebrates are
found here in moderate concentrations. From 29 km downstream, the river is
characterized by high turbidity, silty substrate, and elevated summer
temperatures. Macroinvertebrates are restricted in distribution; trout have
been replaced primarily by carp and flannelmouth suckers, and the channel
catfish has become the dominant game fish (Southwest Energy Study, 1972a).
MINERAL RESOURCES
Currently the major mineral resources being developed in the San Juan
Basin are natural gas, crude oil, uranium, vanadium, zinc, lead, and sand and
gravel (U.S. Soil Conservation Service et al., 1974). Production of most of
the metallic elements, such as zinc, lead, silver, gold, and copper, is
primarily in the Silverton area of the San Juan Mountains in San Juan County,
Colorado. Sand and gravel are produced throughout the basin for secondary
development, such as road construction and preparation of concrete and
asphalt. However, petroleum products, along with helium and coal, are the
most important resources to the basin economy. These major resources, as well
as uranium, will be discussed in greater detail later in this report.
LAND OWNERSHIP AND USAGE
The greatest percentage of land in the San Juan Basin is privately owned
with over 50 percent of the basin in Indian lands (Figure 4). There are four
reservations involved in this ownership pattern, the largest of which is the
Navajo Reservation, covering almost 30,000 km2 and extending into
New Mexico, Arizona, and Utah (U.S. Soil Conservation Service et al., 1974).
The remaining three reservations include the Ute Mountain Ute Indian
Reservation (2,300 km2 in Colorado, New Mexico, and Utah), the Jicarilla
Apache Reservation (2,485 km2) in New Mexico, and the Southern Ute Indian
Reservation in Colorado (1,214 km2) (U.S. Soil Conservation Service
et al., 1974).
Approximately 25 percent of the basin land is in Federal ownership (U.S.
Soil Conservation Service et al., 1974). These lands are administered by the
Bureau of Land Management, the U.S. Forest Service, and the National Park
Service. Non-Indian private land is 13 percent of the basin total, and nearly
3 percent is tied up as State and local government land (U.S. Soil
Conservation Service et al., 1974).
Land in the San Juan Basin is primarily used for grazing, which accounts
for over 75 percent of the basin acreage (U.S. Soil Conservation Service et
al., 1974). This figure includes rangeland and timberland used for grazing;
commercial timber that is not grazed accounts for the next largest percentage
of basin usage. Only a small portion of the basin is cropland, with
irrigation farming more common than dryland farming, a consequence of the
23
-------
SAN JUAN BASIN
KM 2
ARIZONA:
COLORADO:
NEW MEXICO:
UTAH:
TOTAL:
AGRICULTURAL
LAND USE
13.177
15.021
25.227
11.185
64.610
IRRIGATED CROPLAND
DRY CROPLAND
MISCELLANEOUS*
TIMBER
—65
—60
LAND
OWNERSHIP
TIMBER AND GRAZING —
PRIVATE LAND
STATE.LOCAL GOVT LAND
NONCRQPLANO GRAZING
— INDIAN LANDS
.40
i
,' — 30
20
10
•URBAN. BARREN LAND. ETC.
NATIONAL PARK SERVICE LAND
BUREAU OF LAND
MANAGEMENT LANDS
—NATIONAL FOREST LAND
Figure 4. Land ownership and usage in the San Juan River Basin.
Source: Modified from U.S. Soil Conservation Service et al. (1974)
24
-------
basin's aridity. The irrigated farmlands (1.6 percent of the available land)
produce mainly feed products, such as hay or pasture, to supplement existing
forage on the range (U.S. Soil Conservation Service et al., 1974). Corn is
another major irrigated product with some vegetable and fruit farming found in
the Durango-Cortez-Farmington areas. Most dry cropland farming (2.3 percent
of the basin area) is in the northern area of the basin in Dolores County,
Colorado; beans and small grains, such as winter wheat, are the leading crops.
Industrial utilization of land, such as mining, oil and gas production,
and urban development, presently occupy a relatively insignificant amount of
space in the San Juan Basin although the potential for development of
widespread energy resources is great. Recreation, including fishing, hunting,
boating, camping, and general vacation activities, is a major usage of basin
land. Recreational utilization of the land is generally compatible with
responsible development of other resources in the area. Included within the
basin are six national monuments and one national park. Use of and
environmental impact to these areas are Federally mandated, and consequently
their importance in the area is disproportionate to their physical size.
Their presence promises to provide a continuing awareness and concern for air,
water, and aesthetic qualities in the basin.
25
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5. ENERGY RESOURCE DEVELOPMENT
Energy development in the San Juan River Basin stems primarily from
utilization of expansive oil and natural gas fields, coal beds, and belts
containing uranium ore. The existing and projected resource developments and
their effect on the aquatic environment in the basin are discussed
individually below.
ACTIVE DEVELOPMENT
Oil and Gas
Extensive oil and gas fields, with associated refineries and processing
plants, are located throughout the San Juan Basin between Aneth, Utah, and
Navajo Reservoir (Figure 5). The basin's natural gas resources are estimated
to equal 370 million m3 (U.S. Soil Conservation Service et al., 1974) and
are drawn from approximately 64 fields and 8,600 wells in the area. Some 63
percent of New Mexico's natural gas reserves and 44.5 percent of the State's
production are from the basin (Grant, 1975). The crude oil reserves are
estimated to equal 159 billion liters, and 370 million m3 of helium
associated with the natural gas is available (U.S. Soil Conservation Service
et al., 1974). In addition to the major oil fields lying along the southern
and western margins of the basin in San Juan and Rio Arriba Counties in New
Mexico (which account for about 6 percent of the State's oil production),
there are also a few small fields in Montezuma, Archuleta, and La Plata
Counties in Colorado and Apache County, Arizona. Approximately 77 percent of
the oil produced in New Mexico is transported out of State for use and
refining (Grant, 1975).
Figure 5 shows the location of the gas-processing plants and oil
refineries in the San Juan Basin. Individually, these wells and pumping
plants utilize only small quantities of land; the major environmental impact
from the resource development results from the disposal of saline waste waters
from the oil field operations. In the San Juan Basin, 7.8 million m3 of
saline waters were disposed of in 1967; these waters varied in total dissolved
solids concentrations from 1,200 mg/1 to 295,000 mg/1 (Upper Colorado Region
State-Federal Inter-Agency Group, 1971d). Other wastes include drilling muds,
waste oil, tank-battery sludge, and pollution resulting from accidental
discharge of crude petroleum products. Increased development results in
increased opportunities for such hazardous spills; in October 1972, for
example, over one million liters of crude oil were spilt into the San Juan
River as a result of a broken 41-cm pipeline (U.S. Environmental Protection
Agency, 1977a).
26
-------
ro
GPP-GAS PROCESSING PLANT
OR -OIL REFINERY
O GAS FIELD
OIL FIELD
Aneth/ I COLORADO
Chaco G
Plateau, Inc. OR
Blanco GPP
GPP
Giant
Industries ORs*:-'Frujt)and
Caribou Four
Corners. Inc.GPP
10 0 K) ZO 3O Kitom«t«rs
Figure 5. Location of oil and gas fields in the San Juan River Basin.
-------
Saline water discharges can come from both producing and nonproducing
wells. Present State and Federal regulations require spotting cement plugs
opposite porous zones in subsurface formations prior to the abandonment of dry
wells (Upper Colorado Region State-Federal Inter-Agency Group, 1971d).
However, substantial salt contributions may exist from wells abandoned before
the State and Federal regulations were enacted. In the San Juan Basin, most
of the saline water from oil field operations is disposed of by subterranean
injection. Wastewaters may also be discharged to holding ponds for disposal
by evaporation or released for utilization by another source such as livestock
watering.
Coal
Substantial amounts of fossil fuels must be extracted in the near future
in order for the United States to satisfy increasing energy demands and
achieve energy self-sufficiency. Coal, 1,000 kg of which is equivalent to the
heating value of 788 liters of oil, is the most likely candidate to be used to
offset shortages in domestic gas and liquid fuel production. Already gaining
in importance in the generation of western electrical power, coal can be
utilized in the production of many synthetic products (U.S. Environmental
Protection Agency, 1976b) and to supplement domestic requirements for natural
gas. It is estimated that the projected need for coal will rise from a 1974
level of 547 billion kg to 1.2 trillion kg in 1980 and 1.9 trillion kg in 1985
(Atwood, 1975).
The vast majority of minable coal in the United States (72 percent of the
Nation's coal resources) is found in the Rocky Mountain and Northern Great
Plains Provinces (Atwood, 1975). Western coal is particularly attractive,
since 43 percent of it is located in thick seams, is close enough to the
surface to strip mine, and is of low sulfur content (Atwood, 1975). The size
of western coal fields is also well suited to establishment of large adjacent
gasification and liquefaction plants.
The major strippable coal areas in the San Juan River drainage basin are
found in New Mexico and Colorado (Figure 6) (Grant, 1975). Other coal
resources in the basin are too deep to be surface mined. Coal throughout the
basin is found in three major geologic formations of Cretaceous age: the
Dakota Sandstone, the Menefee Formation of the Mesa Verde Group, and the
Fruitland Formation (Baltz et al., 1966; Baltz, 1967; Grant, 1975). It is
generally associated with extensive stretches of alternating beds of
sandstones, siltstones, and shales. The quality of the coal in the basin is
variable; however, sulfur content is consistently less than 1 percent, and the
coal contains an average heat value of between 19,300 and 21,200 joules/kg.
The bituminous and subbituminous coal resources of the San Juan Basin are
extensive and valuable, particularly those deposits of the Fruitland
Formation. Since the 1950's, the mining industry has increasingly become a
major factor in the economic development of this area (U.S. Soil Conservation
Service et al., 1974) and certainly will continue to do so in coming years.
28
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A COAL FIRED POWERPLANT
G PROPOSED COAL GASIFICATION PLANT
STRIPPABLE COAL
E MINE
37-00
Figure 6. Location of coal mines, powerplants, and gasification sites in the San Juan River Basin.
-------
It is estimated that 5.4 trillion kg of strippable steam coal exist in
reserve in the San Juan Basin (Grant, 1975). Approximately 40 percent of this
supply is owned by the Navajo Nation and leased to mining developers (Grant,
1975). Presently, two mines are active in the basin: the Navajo Coal Mine,
located south of the San Juan River along the Chaco River, and the San Juan
Mine, situated north of the San Juan River in the vicinity of Shumway Arroyo.
Utah International, Inc. (UII), operations in the Navajo Coal Mine support the
Four Corners Powerplant, one of the largest coal-fired electric generating
facilities in the world (U.S. Soil Conservation Service et al., 1974). UII
also mines coal owned by Western Coal Company (San Juan Mine) to provide fuel
for the San Juan Powerplant. Both UII and Western Coal are planning large
expansions of their Indian-leased acreage.
In addition, Peabody Coal-Thermal Industries and Santa Fe Industries are
expected to begin strip mining at the Star Lake Mine in the southeastern
portion of the basin in 1978; the coal will be shipped to the Coronado Power-
plant near St. Johns, Arizona. A new 2,000-MW electric generating plant may
be proposed for development by 1980; this plant would operate using coal from
the Bisti area (Grant, 1975). There are also two smaller mines in Colorado in
the development stages: one underground mine near Hesperus in La Plata
County, and the Mel Martinez Mine, a strip mine 16 km southwest of Pagosa
Springs (Corsentino, 1976). The 8.1 km* Hesperus mine, operated by Energy
Resources, Ltd., in Denver, has exploration and drilling planned with possible
future development of its estimated 90.7 billion kg coal reserves. The Mel
Martinez Mine, operated by Milton Fuller of Durango, is part of a 0.3 km*
lease; there are plans for production of 226 million kg of coal from this mine
by the middle to late 1970's (Corsentino, 1976).
Increased coal production in the West will have a significant
environmental impact, particularly on water resources of the region. Surface
mining of the enormous coal reserves requires approximately 54.2 to
61.8 thousand liters of water per kg of coal mined (Adams, 1975). Conversion
of coal into electricity requires large quantities of water. In 1974
consumptive use by the Four Corners Plant equalled 23.4 million nr, and
4.9 million m^/yr were depleted by one active unit of the San Juan Plant
that same year (U.S. Bureau of Reclamation, 1976a). Transportation of western
low sulfur coal to powerplants by coal slurry line can require an additional
2.5 to 3.7 million nrVyr of water to supply slurry to a 1,000-MW electric
generating plant (Adams, 1975). These water demands are immense since most
streams in the resource area are dry during much of the year and only limited
amounts of ground water are available for mining.
Strip mining can also have great impact on water quality in the resource
area. Mining alters the porosity and permeability of overburden land, and
pollution of both ground and surface waters can occur when basin runoff drains
through mine spoils in unrestored land. Reclamation of the stripped area is
difficult in an arid climate where sufficiently large quantities of water are
not available to allow reestablishment of plant cover.
30
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Powerplants
San Juan Powerplant —
The San Juan Powerplant is located in San Juan County, New Mexico,
approximately 7.5 km northwest of Farmington. Fuel for the plant is coal
purchased from a strip mine owned by Western Coal Company in the immediate
vicinity (the San Juan or Fruit!and Mine). Estimated coal consumption for the
plant is 3.7 million kg/day for each 345 MW unit, two of which are being
utilized initially (Southwest Energy Study, 1972b). Two additional 450 MW
units are expected to be completed around 1980 (Grant, 1975), bringing the
total plant coal consumption to 4.5 billion kg/yr.
Cooling water is diverted by weir from the San Juan River through a
screened 8 km underground pipeline to a holding reservoir located 2 km
southwest of the plant (U.S. Bureau of Reclamation, 1971). This reservoir has
a total capacity of 1.6 million m3 with approximately 1.0 million m3 as
active storage and is lined to prevent seepage (U.S. Bureau of Reclamation,
1971). Most of the water for the plant is consumed; as much as 7.4 million
m3/yr may be diverted for each 345 MW unit (U.S. Bureau of Reclamation,
1971). Most of this is evaporated in the cooling tower to remove turbine
heat. For a 1,000 MW generating plant with a conventional cooling tower,
evaporative loss alone can exceed 18.5 million m3/yr (Adams, 1975).
Relatively small amounts of water are to be used in the handling of waste ash.
Any surface water drainage from the plant flows into Shumway Arroyo to the
west of the plant and eventually reaches the San Juan River. Present water
assignments have allocated 19.7 million m3/yr average depletion of water to
the San Juan Plant (U.S. Bureau of Reclamation, 1976a). Needed additional
water may be made available from Navajo Reservoir under a contract that calls
for a maximum of 24.7 million m3 consumption annually (U.S. Bureau of
Reclamation, 1971). The present plan to utilize all diverted water offers a
good alternative to the problem of returning saline wastewater to the San Juan
River drainage without wasting water through pond evaporation to control
salinity.
Four Corners Powerplant —
Two 175 MW units of the Four Corners Powerplant were completed in 1963 to
provide power to the Phoenix area (Grant, 1975), and the third unit (225 MW)
went into operation in 1964. Since that time (in 1969 and 1970), two more
pulverized coal-burning steam electric generating units (800 MW each) have
been added to bring total generating capability to that needed to handle
electric generating needs of 1.5 million people (U.S. Bureau of Reclamation,
1976b). A variety of communities are served by these latter two units, with
48 percent of production going to Los Angeles, 25 percent to Phoenix, 7
percent each to Tucson and the Las Cruces-El Paso areas, and the remainder to
other customers throughout New Mexico (Grant, 1975).
The plant, and its associated Navajo Mine, are located south of the
San Juan River in the vicinity of Chaco Wash. At full load and with all five
units in operation, a maximum of 25.4 million kg/day of the subbituminous coal
is consumed (U.S. Bureau of Reclamation, 1976b). Generally, however, plant
31
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operation is less than 70 percent of fuel capacity with an average consumptive
rate of 17.2 million kg/day. Wastewater from the plant has been discharged to
the San Juan River via Chaco Wash since 1963. In recent years, the Four
Corners Powerplant has come under increasingly stringent Federal and State
pollution regulations.
The State of New Mexico has authorized diversion of up to 63.6 million
nvVyr of water from the San Juan River for operation of the Four Corners
Plant. The plant utilizes a cooling pond (Morgan Lake) for dissipation of
waste heat and, on an average, diverts 34 million FIT*, resulting in a 2
percent reduction in average annual river flow between the diversion structure
and Shiprock (U.S. Bureau of Reclamation, 1976b). Of this diversion, it is
estimated an average of 11 million nvVyr of water ultimately returns to the
San Juan River via Chaco Wash. The remainder is lost to evaporation, seepage
to ground water, or consumption in plant operations. Slowdown (flushing) of
Morgan Lake was initiated to eliminate accumulation of return water containing
total dissolved solids levels in excess of 900 mg/1, which could do damage to
plant condensers and auxiliary cables. This release of water from Morgan
Lake, which then travels 18 km down Chaco Wash to the San Juan River, occurs
approximately every three months (Southwest Energy Study, 1972b). In 1975,
9.0 million m3 of blowdown waters were discharged into Chaco Wash (U.S.
Bureau of Reclamation, 1976b); the plant has requested a modification of the
present discharge permit to allow 20.3 million nvVyr of blowdown from Morgan
Lake into Chaco Wash.
Plant effluent discharged to Morgan Lake includes quantities of lime,
alum, salt, sulfuric acid, and sodium hydroxide (Southwest Energy Study,
1972b). Both fly and bottom ash are found in substantial quantities in the
lake sediments. Table 8 presents elemental data from water and sediment
samples in Morgan Lake and its seepage water. With the exception of fluoride,
and possibly beryllium, these water concentrations do not exceed established
EPA criteria for beneficial uses (U.S. Environmental Protection Agency,
1976c). It is of interest that the high sulfate levels in Morgan Lake
indicate a greater amount present than that calculated from all known
additions. It is postulated that this increase is due to S02 stack emission
fallout, although it may also be due to flushing of desert rock and soils
(U.S. Environmental Protection Agency, 1976c).
It should be noted that the first major cleanup effort in Morgan Lake has
recently begun; the Arizona Public Service Company has agreed to spend
$6 million to bring the cooling pond into compliance with Federal water
requirements. This effort should ultimately result in improved water for
livestock consumption, fishing, and recreational activities in the San Juan
River downstream from Chaco Wash.
The Southwest Energy Study (1972b) reports "of the several wastewater
parameters investigated at the Four Corners Plant, heavy metals are
potentially the most significant and serious threat to the aquatic biota of
the San Juan River." Sources of heavy metal pollution include fallout from
stack emissions, coal storage runoff, leachate from fly ash landfill sites,
and runoff from strip mine tailings. Wastewater from wet scrubbers is also a
32
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TABLE 8. TRACE ELEMENT CONCENTRATIONS IN MORGAN LAKE AND MORGAN LAKE
DISCHARGE TO CHACO WASH (mg/1) IN 1973
El ement
Arsenic
Antimony
Al umi num
Beryllium
Boron
Bi smuth
Barium
Cadmium
Chromium
Copper
Calcium
Cobalt
Fluoride
Iron
Lead
Manganese
Magnesium
Mercury
Silicon
Selenium
Tin
Titanium
Vanadium
Zinc
Zirconium
"Plant Intake"
Lake Water
<0.01
0.007
0.35
<0.1
2
<0.3
<3
<0.001
<0.02
0.1
93
<1
2.3
<0.1
<0.001
<0.1
43
<0.001
4
0.001
<0.1
<0.1
<0.1
<1
<0.1
Sediments
(mg/kg)
2.7
—
100,000
<1
160
<10
—
—
105
120
>50,000
28
65
50,000
16.5
390
10,000
<0.05
100,000
5.4
<30
30,000
65
40
300
Morgan Lake
Seepage to Chaco River
___
—
—
—
<0.1
<0.001
<1
<0.001
0.013
332
<1
1.4
0.115
<0.001
0.038
2,900
<0.001
17
—
<0.001
—
0.060
—
Source: Modified from U.S. Bureau of Reclamation (1976b).
33
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potential source of mercury, radionuclides, and heavy metals. Table 9
presents the elemental composition of area coals, overburden, ashes, and stack
particulates, and the calculated ground deposition of selected elements.
Although some elemental concentrations in Navajo Coal appear quite large, only
boron, beryllium, lithium, and molybdenum exceed the average concentrations in
the crusted rocks (Mason, 1958). Fly ash and stack particulates, however,
have significantly elevated levels of arsenic, beryllium, bismuth, boron,
cadmium, gallium, germanium, lead, lithium, molybdenum, and zirconium. Of
these, water quality criteria exist for arsenic, beryllium, boron, cadmium,
lead, lithium, and molybdenum (U.S. Environmental Protection Agency, 1976c).
Table 10 presents the calculated quantity of materials emitted to the air from
the Four Corners Powerplant at full capacity in 1974 (2,175 MW).
High levels of mercury have been measured in the flesh of fish taken from
Morgan Lake in the vicinity of the Four Corners Powerplant, and in 1970 the
New Mexico Environmental Improvement Agency issued warnings against eating
fish found in both Morgan Lake and Navajo Reservoir (Southwest Energy Study,
1972b). It is not known that the plant is entirely responsible for the high
levels of mercury found in Morgan Lake fish; these levels may be a natural
phenomenon of the area. However, the Four Corners Plant does emit significant
amounts of mercury to the atmosphere annually from its stacks. In 1971,
approximately 1,900 kg of mercury were released to the air (Southwest Energy
Study, 1972b); the average mercury emission reported by the U.S. Bureau of
Reclamation (1976b) was equivalent to 710 kg (Table 10).
It has been proposed that high mercury levels in powerplant-associated
water bodies may be an especially acute problem as a result of S02 fallout
producing acidification of the water (Southwest Energy Study, 1972b). The
methylation of mercury by biological activity in aquatic systems produces both
monomethyl mercury, which has a strong tendency to remain in water solution,
and dimethyl mercury, which tends to evaporate into the atmosphere (Lambou,
1972). In more acidic waters, a greater proportion of the nonvolatile
monomethyl mercury is produced than in alkaline conditions, and the dimethyl
form tends to decompose to the monomethyl form. Thus in acidic conditions,
the total amount of mercury, as monomethyl mercury, dissolved in water should
be greater (Lambou, 1972). Further investigation is needed to determine the
extent to which such biological methylation is occurring in the San Juan
Basin.
FUTURE DEVELOPMENT
Coal Gasification
In the mid-1800's, a process for converting coal to a low BTU gas was
developed and was successfully tested in a pilot plant in Germany in 1930
(U.S. Bureau of Reclamation, 1977c). This work led to the design of the Lurgi
Pressure Gasification Process, developed by the Lurgi Mineralbltechnik, GmbH,
34
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TABLE 9. TRACE ELEMENT COMPOSITION (pg/g) OF VARIOUS COALS AND MINING DISCHARGES IN THE
SAN JUAN RIVER BASIN
CO
Ol
Element
Antimony
Arsenic
Barium
Beryllium
Bismuth
Boron
Bronri ne
Cadmium
Cerium
Cesium
Chromi urn
Cobalt
Copper
Dysprosi urn
Erbium
Europium
Fluorine
Gadolinium
Gallium
Germanium
Gold
Kafni urn
Hoi mi urn
Iodine
Iridium
Lanthanum
Lead
Lithium
Lutecium
Manganese
Mercury
Molybdenum
Neodymium
Nickel
Niobium
Osmium
Palladium
Platinum
Praseodymi urn
Rhenium
Rhodium
Navajo Nine Coal
Average from
7 Seams
0.42
1.20
140.00
3.40
<0.10
75.00
1.70
0.66
15.00
0.32
4.60
1.6ff
44.00
0.68
0.24
0.46
210.00
<0.33
12.00
0.90
<0.10
0.44
<0.11
0.45
<0.10
10.00
5.50
85.00
<0.35
130.00
0.01
4.90
13.00
2.90
5.60
<0.10
<0.10
<0.10
3.40
<0.10
<0.10
Navajo
Nine
Comp
0.13
1.1
1
1.5
1
80
1
4
2
14
44
8
<6
6.3
50
40.
0.08
0.8
4
<2
Burnhatn
Mine Coal
0.3-1.2
0.1-3.0
2-3.0
0-0.2
60.0-150.0
100
0.2-0.4
150-200
100
0.5-8.0
0.1-0.5
1.4-4.0
500
0.2-0.3
3.0-30.0
Bottom
Ash
0.5-0.8
0.8-1.1
0.5
5
10
200
0.7-3.2
20
10
53-57
7-17
30
30
23-26
200
200
0.3-0.6
3
20
10
Fly
Ash
0.4
11
1.0
6
10
700
1.6
60
10
80
100
400
30
62
200
300
0.13
10
30
10
Navajo Mine Coals
Stack
Partlculates
0.9
30
0.5
5
10
300
4
20
10
65
900
40
30
50
200
200
0.30
3
20
10
Navajo Mine
Overburden
(Average)
0.46
2.0
717
<1
<30
41
<10
16
23
40
417
27
<10
36
83
455
0.055
<10
19
<20
Calculated
Ground
Deposition*
0.39-0.5
4.5-39.3
0.1-1.1
53-455
0.04-0.45
0.1-0.6
(Continued)
*@equilibrium
-=- 10,000 to estimate concentration in upper 1/2 cm of soil
-------
TABLE 9. (Continued)
co
en
Element
Rubidium
Rut hlni um
Samarium
Scandium
Selenium
Silver
Strontium
Tantalum
Tellurium
Terbium
Thallium
Thoriam
Thulium
Tin
Tungsten
Uranium
Vanadium
Ytterbium
Yttrium
Zinc
Zirconium
Navajo Mine Coal
Average from
7 Seams
4.60
<0.10
0.75
4.00
0.74
0.03
53.00
0.39
0.20
<0.11
<0.1S
3.60
<0.11
1.40
6.90
0.66
21.00
<1.10
13.0
12.00
140.00
Navajo
Mine Burnham
Comp Mine Coal
2.7 0.1-0.2
<0.2
40
<0.6
20 300-500
6 1.1-27.0
40
Bottom
Ash
0.2-1.5
1
300
3
50-70
10
200
Fly
Ash
6.6
1
500
3
200
100
300
Navajo Mine Coals
Stack
Partlculates
27
1
300
3
60
10
300
Navajo Mine
Overburden
(Average)
10
<0.5
<5
133
<5
35
38
142
Calculated
Ground
Deposition*
0.35-1.96
0.07-0.68
Sources: Modified from U.S. Bureau of Reclamation (1975, 1976b, 1977c) and Westinghouse
Environmental Services Division (1975).
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TABLE 10. CALCULATED EMISSION RATES (g/hr) FROM
THE FOUR CORNERS POWERPLANT, 1974
El ement
Ag (Silver)
As (Arsenic)
B (Boron)
Ba (Barium)
Be (Beryllium)
Bi (Bismuth)
Cd (Cadmium)
Co (Cobalt)
Cr (Chromium)
Cu (Copper)
F (Fluorine)
Fe (Iron)
Ga (Gallium)
Ge (Germanium)
Hg (Mercury)
K (Potassium)
Li (Lithium)
Mg (Magnesium)
Mn (Manganese)
Mo (Molybdenum)
Na Sodium)
Nb Niobium)
Ni Nickel)
Pb (Lead)
Sb (Antimony)
Sc (Scandium)
Se (Selenium)
Si (Silicon)
Sn (Ti n)
Sr (Strontium)
Ti (Titanium)
V (Vanadium)
Zn (Zinc)
Zr (Zirconium)
S02
NOX
Particulates
Total Emission
<45
448
3,991
60,755
~779
<175
—
<175
344
1,688
58,990
>141,000
-425
-414
81
>140,000
<2,022
-140,000
2,036
<31
>143,000
<175
-215
532
<2
-140
407
1,400,000
<600
-3,025
-177
-679
895
-3,015
8,801,814
5,340,136
3,087,528
Source: Modified from U.S. Bureau of
Reclamation (1976b).
37
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a West German company. There are six major steps to this process, which is
the only commercially proven high-pressure process for coal gasification (U.S
Bureau of Reclamation, 1977c):
1. Production of crude gas through gasification of the coal
with oxygen, steam, and pressure in a Lurgi gasifier;
2. Removal of existing phenols, ammonia, dust, and tars in ash form
during quenching and cooling operations;
3. Conversion of the crude gas to a proper hydrogen/carbon
dioxide ratio necessary for methane synthesis;
4. Removal of impurities such as sulfur compounds, from the gas;
5. Synthesis of methane from the gas using a catalytic reaction
between hydrogen and carbon dioxide; and
6. Preparation for pipeline transmission through compression and
dehydration.
Byproducts of this process include tar, tar oil, naphtha, ammonia, crude
phenols, and elemental sulfur. To date, only 16 plants in the world have been
built to use the Lurgi Pressure Gasification Process (U.S. Bureau of
Reclamation, 1977c). In the San Juan Basin, two gasification projects have
been approved for development in the near future: the El Paso Project,
located just outside of Burnham, and the Western Gasification Company (WESCO)
Project, located along Chaco Wash, 13.7 km to the northwest of the El Paso
Complex.
The El Paso Gasification Project will include the construction and
operation of a single complex with associated support facilities on 161.88
km^ of Navajo lease land near Burnham (Grant, 1975). Also located on the
Navajo Reservation, coal for the project is to be supplied and mined by
Consolidated Coal Company (CONSUL) from a new mine in the southern portion of
the existing UII lease area, to the north and adjacent to the gasification
plant site. It is projected that 90.08 km2 of land will be affected by
extracting almost 13 billion kg of coal per year (U.S. Bureau of Reclamation,
1977c). By 1982, it is anticipated that 11.6 million m3/day of substitute
pipeline gas will be produced and transported via a new pipeline to El Paso's
existing San Juan mainline (U.S. Bureau of Reclamation, 1977c).
Water for the El Paso Project will be provided by contract with the Bureau
of Reclamation and diverted south from Bloomfield. The maximum consumptive
use allowed for the project is 18.5 million m3/yr (U.S. Bureau of
Reclamation, 1976a), a quantity that will reduce the San Juan River flow by
approximately 2 percent. In addition, El Paso Company projects it will use
2.4 million nr* of ground water during complex construction (U.S. Bureau of
Reclamation, 1977c).
38
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The Western Gasification Company Project will ultimately construct and
operate two gasification complexes with a total of four plants and the
necessary associated support facilities. Located on the Navajo Reservation,
the project will be supplied with coal from Utah International, Inc. (UII),
through an expansion of its existing Navajo Mine (U.S. Bureau of Reclamation,
1975). It is projected that 113.31 km2 of land will be affected by strip
mining for the project with consumption of as much as 34.5 billion kg of
coal/yr (U.S. Bureau of Reclamation, 1975). Eventual total production of the
project will be 28 million mVday of substitute natural gas, to be achieved
by 1985 when all four plants are operational. The gas will be piped through a
new line where it will join existing facilities owned and operated by
Transwestern Pipeline Company near Gallup (U.S. Bureau of Reclamation, 1975).
Water for the WESCO project will be provided from Navajo Reservoir by
reassignment of existing UII water rights. A maximum of 43.2 million mVyr,
to be piped 15.5 km from the San Juan River, has been allocated to WESCO for
consumption in the coal gasification, cooling, and mining operations (U.S.
Bureau of Reclamation, 1976a), including revegetation of the stripped areas.
In addition, it is anticipated that WESCO will utilize 0.5 million m3 of
ground water in construction of the gasification facilities (U.S. Bureau of
Reclamation, 1975).
There are some environmental impacts that could result from the planned
gasification facilities. Jones et al. (1977) report that "control of water
pollution is a major problem at Lurgi gasification plants." Those impacts
affecting surface water in the region will have maximum adverse effects during
periods of minimum stream flow. Diversion of water from the San Juan River
will result in an increase of salt concentration downstream, since existing
flows that dilute background salt levels will be reduced. The construction of
the plants and associated roads, pipelines, and powerlines, as well as the
mining operations themselves, would be conducive to water and wind erosion of
soil, a problem already acute in the arid area. Both operations intend to
bury processing waste materials along with the mining overburden, which could
possibly result in the percolation of salts, heavy metals, and other
contaminants into ground-water aquifers.
The major pollutants associated with the Lurgi process itself include
ammonia, phenols, organic by-products, hydrogen sulfide, hydrogen fluoride,
carbon dioxide, fatty acids, biological oxygen demand, and suspended solids
(Jones et al., 1977). The WESCO and El Paso plants have zero discharge
design, and theoretically no effluents should be released beyond the plant
boundaries. Instead they are recycled for use in the gasification process or
discharged to lined evaporative ponds. In the case of brief, episodic storm
events, runoff from the plant areas will be routed to line holding ponds,
treated, and either reused or combined with other treated wastewater streams
to avoid contamination of surface waters (U.S. Bureau of Reclamation, 1977c).
Potentially, however, contamination may still follow an extended, heavy
rainfall where collection and treatment facilities are inadequate to handle
the large volumes of water or where failure of a holding pond occurs.
Localized release of trace elements and organic complexes formed during
thermal treatment of the coal are another pollution threat to the watershed
surrounding gasification complexes. Toxic emissions are most likely to occur
39
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during the quenching and cooling processes in the plant. Jones et al. (1977)
state that "even after extensive treatment [of wastewaters], trace amounts of
some species such as organic by-products may still remain. Traces of
carcinogenic -organic materials could enter the environment in the water spray
from cooling towers." Most trace elements of concern from the gasification
process (Table 11) will be disposed of in the ash. However, additional
investigation into the chemical nature of those trace elements that ultimately
leave a Lurgi gasification plant is badly needed.
TABLE 11. MAJOR TRACE ELEMENTS OF CONCERN AS POTENTIAL POLLUTANTS
FROM COAL GASIFICATION FACILITIES
Antimony
Arsenic
Bari urn
Beryl 1 i urn
Boron
Cadmi urn
Chlorine
Chromi urn
Copper
Fl uori ne
Lead
Mercury
Molybdenum
Nickel
Selenium
Sulfur
Tel 1 uri urn
Uranium
Vanadium
Zinc
Source: Modified from Jones et al. (1977).
It should be noted that plans for development of the WESCO and El Paso
facilities recently have been dropped temporarily (Lindquist, 1977). Delay in
construction will ease the anticipated environmental impact on water resources
of the area, and provide a greater opportunity to evaluate alternatives for
management of the Basin's water supplies.
Coal Slurry Line
There is presently proposed the development of a coal slurry pipeline that
will transport coal from Farmington to Walsenburg, Colorado (Corsentino,
1976). This pipeline, which will be operated by Houston Natural Gas, is
expected to begin transport in 1980. The 30.5 cm diameter, 269 km long
pipeline will carry 4.5 billion kg of coal slurry per year to Walsenburg,
where it will join the main slurry line for coal transport to Corpus Christi,
Lubbock, and Houston, Texas (Corsentino, 1976). It is not known at this time
how much water per year, if any, will be required from the San Juan Basin for
operation of the transport line. However, approximately one cubic meter of
water is required to transport one metric ton of coal (Jones et al., 1977).
Thus, about 4.5 million m^ of water/yr would be required for the proposed
line.
40
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Uranium
There are presently no active uranium mill sites in the San Juan Basin.
However, potential uranium exploration sites are being defined in the southern
and western portions of the basin by Exxon Corporation in agreement with the
Navajo tribe on whose land those sites are located. In the past, there were
four uranium mills in the basin: Monument Valley, Arizona; Mexican Hat, Utah;
Shiprock, New Mexico; and Durango, Colorado. Three of these are situated on
the Navajo Reservation (Douglas and Hans, 1975). All four of these mill sites
were closed before 1969, with the Durango plant being the first to shut down
operations in 1963 (Upper Colorado Region State-Federal Inter-Agency Group,
* -7 / 1Q f •
An understanding of radioactive wastes associated with uranium ore
processing is essential, since even low exposures can constitute a major
biological hazard. Strict limitations on the allowable exposure to
radionuclides have been established; each radionuclide has a Federally
assigned maximum permissible concentration (MFC), based upon the amount of
radioisotope that could be ingested from a domestic water supply over a
lifetime without producing any readily detectable biological damage in a
population group (Tsivoglou et al., 1959). Water pollution from the uranium
industry is primarily related to milling activities rather than to
conventional mining operations. In addition to radioactive components that
leach or erode from the tailing piles, liquid milling wastes are frequently
high in total dissolved solids and either strongly acidic or alkaline (Upper
Colorado Region State-Federal Inter-Agency Group, 1971d). Other potential
sources of exposure from tailing piles include inhalation of windblown
particulates or gases diffusing from the piles and external whole body gamma
exposure from the piles (Douglas and Hans, 1975).
Over 95 percent of the uranium ore processed is disposed of as solid waste
(Upper Colorado Region State-Federal Inter-Agency Group, 1971d); more than a
ton of ore must be dumped as tailings to extract 1.8 kg of uranium (Adams,
1975). Over 90 percent of the raw ore's radium compounds remains in this
waste (Upper Colorado Region State-Federal Inter-Agency Group, 1971d), and
milling 1.8 kg of uranium yields 3,275 liters of radioactive waste water.
(Adams, 1975). The tailing piles are highly susceptible to erosion, and even
minimal contact with water can yield an effluent with concentrations of Ra-226
in excess of permissible limits.
Hydroelectric Power
There are presently no hydroelectric powerplants in the San Juan Basin. In
the 1940's there was discussion of building on sites on the Rio Chama and Rio
Grande Rivers above Albuquerque in conjunction with the San Juan-Chama
Projects. At that time, the proposals were dismissed; however, the escalating
price of fuel may trigger a reconsideration of these sites in the near future.
At the present time, there are also proposals to construct pumped-storage
hydroelectric plants on Cement and Cunningham Creeks near Silverton, Colorado
(U.S. Bureau of Reclamation, 1977d). If constructed, these will provide power
during peak load periods. Both facilities would be net energy consumers and
draw power from other sources during periods of low power demands (U.S. Bureau
of Reclamation, 1977d).
41
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6. OTHER SOURCES OF POLLUTION
In the San Juan Basin, there are a number of impacts expected as a
secondary effect of energy, agricultural, and other resource development.
Some of these stem from man's aggravation of natural nonpoint pollution
sources, such as erosion, while others stem directly from the resource
development itself. The extent of post-mining impact in an area depends upon
a number of factors, such as climate and topography, chemical characteristics
of the overburden, and land use following the close of mining operations.
EROSION
The soil types in the San Juan Basin vary with elevation as do climate and
vegetation. In the lower, more arid elevations of the basin, droughts are
common and high temperatures result in desiccation of young seedlings. The
resultant paucity of vegetative ground cover, combined with slow weathering of
rocks, yield poor soils, which contain little organic matter and are highly
susceptible to wind erosion. Sediment yields are high from this area during
summer flash floods, and erosion-related runoff from the desert tributaries
eventually contributes heavily to downstream sediment loading in the basin.
In the process of surface mining, the clearing of vegetation, removal of
overburden, and heavy traffic create conditions that are conducive to
weathering. Sediment erosion from the mined area itself is expected to be
minimal and largely retained within the individual mine pits. However,
spillage of both raw coal and waste products are unavoidable along haul roads.
Windblown coal dust and ash from transportation, storage, and disposal areas
will be deposited throughout the area. These materials are highly mobile and
will find their way into the dry washes and eventually into the San Juan
River.
MINE DRAINAGE
Acid mine drainage is not expected to be a problem in the San Juan Basin
since rainfall is sparse and sediments above and below the coal deposits are
generally high in carbonate materials that effectively neutralize acids
flowing through them (Upper Colorado Region State-Federal Inter-Agency Group,
1971d). However, surface runoff or shallow ground water, such as that from
irrigation return flows, may percolate through mine spoil areas resulting in
increased salts, especially sulfates, heavy metals, or alterations in the pH
of basin waters (Southwest Energy Study, 1972b). This is of special concern
in the old mining areas along the Animas River and in the Burnham area, where
the Navajo Irrigation Project is underway.
42
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URBAN RUNOFF
Energy development in the San Juan Basin will produce many jobs, both in
the construction and operational stages. With the increase in jobs will come
large numbers of people to the energy development sites; in particular the
area of the Navajo Reservation and the central communities of Farmington,
Shiprock, and Fruitland will be affected. The resultant buildup of
communities can be expected to increase the contributions of nonpoint urban
runoff to the basin, in addition to augmenting the consumptive water demands
and burden on existing sewage facilities.
Nonpoint urban runoff is produced by precipitation that washes a
population center, flushing a great variety of city wastes into the nearest
water system. The quality of this runoff is variable and unpredictable;
however, it is typically high in nutrients and suspended sediments. Combined
storm and domestic sewer overflow is a common urban source of organic
pollution to the aquatic ecosystem. Animal wastes, fertilizers, pesticides,
and general street debris are other common urban pollutants.
43
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7. WATER REQUIREMENTS
WATER RIGHTS
It is probable that legal rights to utilize water will become the major
factor in regional or State decisions regarding energy development in the
Upper Colorado Basin. The two principal aspects of Federal law for this area
are the "Law of the River" and associated Colorado River Compact, and the
later-produced Upper Colorado River Compact. The Law of the River is
comprised of a number of court decisions, statutes, compacts, and executive
directives that limit the amount of water available for energy development in
the Colorado River Basin. The 1922 Colorado River Compact is a major
component of the Law of the River, in which the Colorado River is divided into
an Upper and a Lower Basin, each of which are allotted certain amounts of
water (Anderson, 1975). The boundary between the two basins is Compact Point
on the Colorado River, 1 mile downstream from the mouth of the Paria River at
Lees Ferry.
Provisions of this compact require States of the Upper Basin (Colorado,
New Mexico, Utah, and Wyoming) to deliver 9,251.2 million m3/yr of Colorado
River water to the Lower Basin during any period of 10 consecutive years
(Anderson, 1975). In addition, one-half of any resulting deficiency in
surplus water must be shared by each basin to satisfy commitments to the
Mexican Treaty. In 1948, the Upper Colorado River Compact distributed the
waters already consigned to the Upper Basin by granting to each State involved
a certain percentage of the allotted water and to Arizona an annual amount of
61.7 million nv*, since part of Arizona is located within the Upper Basin
(Anderson, 1975). Thus, each State in the Basin is apportioned a particular
share of Colorado River water either on a percentage basis or as a fixed
number of cubic meters per year. If curtailment of use becomes necessary to
meet Lees Ferry delivery obligations, reductions will be made first by any
State that has used more than its allotted share for the preceding years by an
amount equal to its excess use. However, deficiencies will be met first by
withdrawal from mainstem reservoirs to meet the obligation before users are
reduced (U.S. Bureau of Reclamation, 1975).
Under the terms of the Colorado River and Upper Colorado River Compacts,
New Mexico is entitled to 1,033.7 million m^ of consumptive water use of the
Colorado River (U.S. Bureau of Reclamation, 1976a), i.e., 11.25 percent of the
Upper Colorado Basin's allotment after deleting 61.7 million m^ for Arizona.
The developments about the San Juan River, the only portion of the Upper
Colorado Basin in New Mexico, are the primary users of this water. Under New
Mexico law, the place and purpose of use of an assigned water right, and the
44
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point at which diversion takes place, can be changed upon issuance of a permit
by the State Engineer. The State Engineer must determine that the change will
not impair any existing water rights before such a permit will be issued;
usually the reassignment of existing irrigation water is the source for new
permits.
WATER AVAILABILITY
New Mexico has been allocated 1,033.7 million m3 of consumptive use of
the Upper Colorado River as part of the Colorado River and Upper Colorado
River Compacts. However, recent water supply records suggest the flow of the
Colorado River is not so great as was initially believed; the period from 1906
through 1930, when the Upper and Lower Basins were apportioned, had the
greatest surface runoff experienced within the last 450 years (Stockton and
Jacoby, 1976). The Bureau of Reclamation (1976a) estimates the amount
actually available to depletion in the San Juan Basin by New Mexico is only
896.7 million nvvyr. Of this amount, 71.5 million m3/yr is now lost to
mainstem evaporation (U.S. Bureau of Reclamation, 1976a). All of this amount
allowed for depletion by New Mexico (896.7 million m3/yr including
evaporation) has been committed to existing or future developments (Table 12).
Outside New Mexico, surface water consumption in the San Juan drainage area is
largely confined to Colorado. Water is primarily used here to support
agriculture and presently is of minimal impact to the basin although
irrigation in the Mancos Shale area does contribute salt loads to the river.
In this state, there also occur complex interbasin water transfers that make
assessment of water consumption from the San Juan River very difficult.
However, since the anticipated energy development in the basin will primarily
occur in New Mexico, water consumption in the other States is not heavily
considered in this report.
The average annual discharge of the San Juan River at Bluff, Utah, for the
1914-65 period equalled 2,332.5 million m3 (U.S. Soil Conservation Service
et al., 1974); the major water use within the Basin during this period of time
was irrigation. While an annual consumption allotment of 897 million m3
would not appear to endanger a stream with an average annual flow of 2,333
million m3, the highly variable discharge of the San Juan River results in
potential problems. Figure 7 shows annual oversize flows for water years,
1915 through 1970. As can be seen, for five years of record the annual flow
was less than the authorized consumptive use. Also apparent is that for the
past 15 years, the 10-year average flows have been well below the 2,333
million m3 average cited. For several days in both 1934 and 1939, USGS flow
records indicated zero discharge in the San Juan River at Mexican Hat.
Although the presence of the Navajo Reservoir provides an ability to control
discharge and maintain a minimum flow in the river, increased consumptive use
of water may well result in periods of no discharge.
45
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TABLE 12. PRESENT AND PROJECTED DEPLETIONS OF WATER IN THE
SAN JUAN RIVER BASIN
Average
Annual
Depletion
1974 Users
Mainstem reservoir evaporation
Navajo Reservoir evaporation
Power -
Four Corners Powerplant
San Juan Powerplant
San Juan-Chama Project
Irrigation -
Hammond Project
Hogback expansion
Other existing (1974)
Irrigation
Municipal and industrial , fish
and wildlife, and recreation
Subtotal
Additional Future
Power -
Four Corners Powerplant
San Juan Powerplant
San Juan-Chama Project
Irrigation -
Hammond Project
Hogback expansion
Navajo Indian Irrigation Project
Animas-La Plata Project
Municipal and Industrial -
Utah International Gasification
Project
El Paso Natural Gas
Farmington municipal and industrial
Gallup municipal and industrial
Other
Subtotal
TOTAL
(m3xl 06)
71.542
32.071
23.436
4.934
56.740
9.868
2.467
102.380
16.035
319.473
24.670
14.802
78.943
2.467
9.868
278.769
41.939
43.172
18.502
6.167
9.868
48.106
577.273
896.746
(acre-feet)
58,000
26,000
19,000
4,000
46,000
8,000
2,000
83,000
13,000
259,000
20,000
12,000
64,000
2,000
8,000
226,000
34,000
35,000
15,000
5,000
8,000
39,000
468,000
727,000
Source: Modified from U.S. Bureau of Reclamation (1976a)
46
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500 r-
400
6 300
r-
X
l_
N
IE 200
100
J L
J L
J L
1915
20 25 30
35 40 45
Year of Record
50 55 60 65 70 75
Figure 7.
Mean annual discharge in the San Juan River at Bluff. (Solid line
is the mean annual discharge; dashes represent a 10-year traveling
mean.)
JUAN RIVER WITHDRAWALS
Water from the San Juan River is withdrawn to serve many functions. In
addition to providing water for energy development in the Four Corners area,
it is used for satisfaction of agricultural needs, utilization in a number of
domestic capacities, and maintenance of recreational areas. These other water
uses are discussed in greater detail below.
Energy Resource Development
„
In 1974, all users depleted 319.5 million mj of water from the San Juan
River; this'value is slightly less than half of the total consumption
(896.7 million m3/yr) that has been authorized for New Mexico in the Basin
(Table 12). Of this amount, only 28.4 million rrrVyr of water was consumed
by two energy developments, the Four Corners Powerplant and the San Juan
Powerplant.
When all authorized users are active in the future, energy developments,
including the two powerplants and two gasification projects, will consume
129.5 million nrVyr of San Juan River water, or 14.6 percent of the
authorized depletion for the Basin in New Mexico.
47
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Irrigation
The major factor limiting agricultural production in the San Juan Basin is
availability of water for irrigation. In 1974, the average annual depletion
of water attributable to irrigation from the basin in New Mexico was 102.4
million m3, with an additional 12.3 million m3/yr lost to the Hammond and
Hogback Projects (U.S. Bureau of Reclamation, 1976a). Included here are the
major irrigation developments, existing and proposed, around the San Juan
Basin.
Navajo Indian Irrigation Project —
The Navajo Indian Irrigation Project (NIIP) was authorized as part of the
Upper Colorado River Storage Project in June 1962. Its principal purpose is
to irrigate 447.71 km^ of Navajo-owned land in the general area south of
Farmington in northwestern New Mexico (U.S. Bureau of Indian Affairs, 1976).
Included in the planning for the NIIP is the construction of a hydroelectric
plant to generate electricity needed for delivery of the necessary volumes of
irrigation water for the croplands. This plant is to be located adjacent to
Navajo Dam on the southern bank of the San Juan River; however, final
construction of the plant has been delayed pending litigation over the
environmental impact its development will have on the area (J. Peterson,
1977).
The courts have authorized a maximum annual average diversion of 626.6
million m3/yr of water to be drawn from Navajo Reservoir for the project,
with a projected total depletion of 313.3 million m3 (U.S. Bureau of Indian
Affairs, 1976). This diversion figure is equivalent to approximately one-half
the annual inflow to Navajo Reservoir (U.S. Bureau of Reclamation, 1977c);
however, it is projected by the Bureau of Indian Affairs (1976) that only
407.0 million m3 will actually need to be diverted to support project lands
and consumptive use will be 278.8 million m3.
Diversion to the NIIP was begun in spring 1976, and it is expected that
full diversion for irrigation of the total project acreage will be achieved by
1987 (J. Peterson, 1977). State and Federal agencies estimate that when
diversion has reached full capacity, there will be 128.3 million m3 per year
of return flow from the project (U.S. Bureau of Reclamation, 1975). Water
percolating down through the soil will accumulate as ground-water storage
until it rises to the level of specially installed drain pipes located 2.4 m
below the soil surface, which will drain the water off into the San Juan
River. Engineering estimates are that 10 years will be required to raise the
'ground water table to the drain tile level (U.S. Bureau of Reclamation, 1975).
It is estimated that up to 31.6 million m3/yr of this return flow (25
percent of the total) would flow into the drainage of Chaco Wash through the
old mining areas of Burnham (U.S. Bureau of Reclamation, 1975). Water flowing
through this area would be intercepted by a diversion channel and routed to
Cottonwood Arroyo. This flow could then be monitored for any uptake of trace
elements or salt accumulation as it enters and leaves the mine area. There
is, however, some disagreement concerning the fate of the 128.3 million m3
48
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of return flow. Sprinkler irrigation is being used for the NIIP, and in light
of expected water losses resulting from evaporation and sprinkler
inefficiencies, it is possible that no deep percolation losses to the soil
will occur from the irrigation and that the 128.3 million m3 will be
consumed rather than returned to the San Juan drainage system (C. Caruso,
Assuming annual diversion to the NIIP reaches the 407.0 million m3
projected as necessary for maintenance of the project lands, water available
to a downstream fishery in the San Juan Basin can be expected to diminish.
The Bureau of Indian Affairs (1976) reports that in a worst-case situation,
during the irrigation season of a drought year, assuming a discharge of 15
m-Vsec at Navajo Dam and all authorized irrigation, municipal, and
industrial diversions active, the San Juan River is expected to become dry
below Shiprock for many miles although fisheries immediately below the dam
would be satisfactorily maintained. Many of the native fish to the basin,
some of which are already endangered or threatened, such as the Colorado
squawfish, roundtail chub, and mottled sculpin, occupy the immediate stretch
of the river below Shiprock (U.S. Bureau of Indian Affairs, 1976). The
likelihood of such a worst-case situation occurring is intensified
substantially if the anticipated return flow from the NIIP is instead
irretrievably lost to the basin through consumption.
Hammond Project --
The Hammond Project is located along the southern bank of the San Juan
River in a 32 km band stretching from Blanco to Farmington (D. Gjere, 1977).
The project was authorized in 1956 by the Colorado River Storage Act and was
completed in 1962.
Operated by the Bureau of Reclamation, the project provides irrigation
water for 15.90 km2 of land, the majority of which has previously been
utilized for grazing (D. Gjere, 1977). Major project works include the
Hammond Diversion Dam, situated 3.2 km upstream from the town of Blanco, an
associated hydraulic-turbine-driven pumping plant, and a 47-km gravity canal
(D. Gjere, 1977). Needed water is generally available from the San Juan River
streamflow but can be supplemented by storage releases from Navajo Reservoir.
In 1974, average annual depletion from the San Juan River attributable to the
Hammond Project was 9.9 million m3 (U.S. Bureau of Reclamation, 1976a). The
Bureau of Reclamation (1976a) predicts future water needs for the project will
deplete an additional 2.5 million m3 per year.
Hogback-Fruitland Project —
The Hogback-Fruitland Project is a small irrigation project operated by
the Bureau of Indian Affairs in the area of Fruitland. south of the San Juan
River. This project, in 1974, depleted 2.5 million m3 water from the flow
of the San Juan River, and future needs are expected to increase to an
additional 9.9 million m3 per year, a total of 12.3 million m3 (U.S.
Bureau of Reclamation, 1976a).
49
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Florida Project --
The Florida Project is operated by the Bureau of Reclamation to serve
irrigation needs in the vicinity of the Florida River, a tributary to the
Animas River. The major structure of the project is Lemon Dam. In operation
since 1963, the project was designed to maintain a minimum flow of
0.283 nrVsec in the Florida River from November through April (Nelson et
a I., 1976)•
Mancos Project --
The Mancos Project is located on the West Mancos River and consists of
Jackson Gulch Dam and associated Jackson Gulch Reservoir. The stretch of the
river affected by the project is from the dam 18 km downstream to its
confluence with the Mancos River.
For the project, excess spring runoff from the West Mancos River is
diverted via a direct diversion canal 4.2 km west into Jackson Gulch Reservoir
(Nelson et al., 1976). The water is stored here until such time as irrigation
needs in the summer months exceed the water available from normal streamflow.
At that time, water is released back into the river about three kilometers
downstream from the dam.
Animas-La Plata Project --
The Animas-La Plata Project, located between the Animas and La Plata
Rivers, will be a multiple-use water resource program developed by the Bureau
of Reclamation. This project, which has been authorized but not constructed,
will furnish municipal and industrial water to the cities of Durango, Aztec,
and Farmington and provide for utilization of resources on the Southern Ute
and Ute Mountain Ute Indian Reservations (U.S. Bureau of Reclamation, 1977a).
The project will provide for flood control and irrigation of land in the
La Plata and Mancos River drainage, as well as create habitats for fish and
wildlife and encourage recreational expansion through the creation of two main
storage lakes, the Ridges Basin and Southern Ute Reservoirs.
Land to be irrigated by the project will be served primarily by sprinkler
irrigation systems. It is projected that when completed the Animas-La Plata
Project will have an average annual depletion of 41.9 million m3/yr (U.S.
Bureau of Reclamation, 1976a). However, the Bureau of Reclamation (1977a) and
the Southwest Energy Study (1972a) indicate that the annual depletion could go
as high as 180.1 to 190.0 million m3. It has been suggested that sources of
water for the project might include exploitation of ground water in the area
if it proves not to be excessively high in mineral content, or augmentation of
existing sources either by efficient land use practices, recycling of waste,
or weather modification (Southwest Energy Study, 1972b).
50
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Municipal and Industrial
There are a number of additional requirements for water in the San Juan
Basin. These include domestic, manufacturing, governmental, and commercial
needs. The total withdrawal requirements for these purposes, based on 1965
conditions, were 28.0 million m-*, of which 8.9 million nr* were consumed
(Upper Colorado Region State-Federal Inter-Agency Group, 1971b). About 80
percent of this requirement is provided for by surface water, the remainder by
ground water. Tables 13 and 14 summarize municipal, domestic, and industrial
requirements for 1965 conditions and projected needs.
The average domestic consumption within the basin (0.32 m3/capita/day)
is quite low compared to national averages (Upper Colorado Region State-
Federal Inter-Agency Group, 1971b). This is primarily due to the lack of
adequate water distribution facilities in the region. An estimated 67 percent
of the regional population is served by 54 municipal systems (Upper Colorado
Region State-Federal Inter-Agency Group, 1971b). The remaining 33 percent of
the population is served by rural-domestic sources (Upper Colorado Region
TABLE 13. SUMMARY OF 1965 MUNICIPAL AND INDUSTRIAL WITHDRAWAL
WATER REQUIREMENTS IN THE SAN JUAN RIVER BASIN BY
SYSTEM AND SOURCE
Source
Ground Water Surface Water
System
Basin total
7.524
20.476
Total System
Withdrawal
Requirements
Municipal
Rural -domestic
Self-supplied manufacturing,
commercial , and governmental
4.564
1.480
1.480
15.789
0.1.23
4.564
20.352
1.604
6.044
28.000
Source: Modified from Upper Colorado Region State-Federal Inter-Agency
Group (1971b).
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TABLE 14. SUMMARY OF PROJECTED MUNICIPAL AND INDUSTRIAL
WATER REQUIREMENTS IN THE SAN JUAN RIVER BASIN
per year)
Water Use
WITHDRAWALS
Domestic
Manufacturing
Governmental
Commercial
Total
DEPLETIONS
Domestic
Manufacturing
Governmental
Commercial
Total
1965
15.048
4.687
3.578
4.687
28.000
6.044
0.741
0.370
1.727
8.882
1980
22.326
8.388
6.661
8.758
46.133
12.828
1.357
0.863
3.578
18.626
2000
34.291
15.295
12.705
16.405
78.696
20.106
2.714
1.850
7.278
31.948
2020
49.586
27.754
20.846
29.727
127.913
29.357
5.304
4.194
14.555
53.410
Source: Modified from Upper Colorado Region State-Federal Inter-Agency
Group (1971b).
State-Federal Inter-Agency Group, 1971b). The rural-domestic water
requirement is 1.6 million m3, of which 1.5 million m^ is provided by
wells (Upper Colorado Region State-Federal Inter-Agency Group, 1971b).
Domestic consumption also has definite seasonal fluctuations with maximum
consumption occurring during June, July, and August. Manufacturing
consumption within the basin is primarily by refineries, dairies, meat-packing
plants, saw and planing mills, and concrete manufacturers.
52
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Fish and Wildlife
Fish and wildlife are relatively small water "consumers" in the Upper
Colorado Region. For fisheries, the estimated consumptive water use in 1965
(Upper Colorado Region State-Federal Inter-Agency Group, 1971c) for the Upper
Colorado Region was 8.2 million m3 (Table 15). This value is based upon
water depletions at fishing lakes and fish hatcheries. Evaporation from the
former is responsible for most of the water consumption reported, since water
in fish hatcheries generally passes through troughs and concrete raceways,
having only limited surface area. The consumptive value for the San Juan
River Basin alone is not known at this time; however, it is the only portion
of the Upper Colorado Region expected to develop future problems with
unsatisfied demands for sport fishing (Upper Colorado Region State-Federal
Inter-Agency Group, 1971c).
Estimates of water consumed at wildlife facilities in the Upper Colorado
Region in 1965 are also shown in Table 15. Consumptive use of water at these
facilities was very small, primarily because only a limited number of
waterfowl impoundments existed at the time, and other users are relatively
insignificant (Upper Colorado Region State-Federal Inter-Agency Group, 1971c).
TABLE 15. SUMMARY OF 1965 CONSUMPTIVE WATER USE BY FISH AND WILDLIFE
IN STATES OF THE UPPER COLORADO REGION
Fishery Wildlife
State Water Consumption Water Consumption
(m3xl06)
Arizona
Colorado
New Mexico
Utah
Wyomi ng
Total
0.696
3.280
0.277
3.972
0.037
8.262
0
0.184
0.217
5.790
0.002
6.193
Source: Modified from Upper Colorado Region State-Federal Inter-Agency
Group (1971c).
53
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The U.S. EPA (Bovee et al., 1977) has demonstrated that consideration of a
single in-stream use as the basis for a flow recommendation is inadequate.
Methodologies have been developed for measurement of a variety of in-stream
requirements in the Tongue River. These requirements include sediment
transport, mitigation of adverse impacts of ice, evapotranspiration loss, and
fisheries, including spawning, rearing, and food production. The EPA field
tests indicate that flow requirements for any particular use vary in
importance throughout the year; thus, for all seasons, satisfaction of basic
requirements for fisheries in a river will not adequately protect all
in-stream uses (Bovee et al., 1977). It should be noted that typically
minimum flow regulations are established using the basic requirements for
fisheries in a river, and frequently even these basic needs are not met. For
example, as part of the Mancos River irrigation project, the Fish and Wildlife
Service recommended that a flow of 0.708 m-vs be bypassed during the annual
reservoir filling period to protect existing fisheries in the stream (Nelson
et al., 1976). However, this recommended bypass level has not been realized;
at times only 0.085 m3/s, a flow barely sufficient to satisfy the municipal
needs of Mancos, Colorado, has been passed.
Livestock
Livestock is a relatively large consumer of water in the San Juan River
Basin. Based upon 1965 conditions, 12.8 million m^ of water was consumed in
annual livestock needs, with nearly 79 percent of the loss (10.1 million m3)
incurred by evaporation from stock watering ponds (Upper Colorado Region
State-Federal Inter-Agency Group, 1971b). In 1965, less than 5 percent of the
livestock requirement was provided for by ground water. It is projected that
by the year 2020 (Upper Colorado Region State-Federal Inter-Agency Group,
1971b) water requirements for livestock will equal 21.2 million nr/yr,
almost double that of 1965 conditions.
Export
There are several small ditches in the San Juan Basin that divert water
from the headwaters of the San Juan River in Colorado to the Rio Grande Basin.
The first of these diversions was opened in 1923; in 1965 approximately 3.1
million m3 were exported from the basin (U.S. Soil Conservation Service et
al., 1974).
In 1971, the export of surface water to the Rio Grande Basin through the
San Juan-Chama Project was initiated. When completed, the project will divert
135.7 million m3 per year into the Rio Grande (U.S. Bureau of Reclamation,
1976a). The project includes two diversion dams: the Oso, located on the
Navajo River, and the Blanco Diversion Dam, located on the Rio Blanco. The
project diverts water from three sources: the Navajo River, the Little Navajo
River, and the Rio Blanco. The diverted water is transported through tunnels,
conduits, and siphons to the Azotea Tunnel, which passes under the Continental
54
-------
Divide to the Rio Grande Basin in New Mexico. The project was sponsored by
the Bureau of Reclamation to irrigate lands in the Rio Grande Basin and to
provide a municipal water supply for the city of Albuquerque (Nelson et al.,
Hydrologic data indicate that streamflows have been significantly reduced
since construction of the project dams; the reduced flows have resulted in
loss of some riffle areas in the affected streams and a reduction in biotic
production. Generally, water quality has remained high in the Navajo River
and Rio Blanco, with the same fish and aquatic insects reported as found in
preimpoundment studies. However, followup studies (Nelson et al., 1976)
indicate that minimum flows are inadequately maintained during the irrigation
season and that some silt accumulation is occurring above the two dams.
IMPORT OF WATER
Existing
Since 1957, the Montezuma Valley Irrigation Company (MVIC) has diverted
approximately 143.1 million m3/yr of water from the Dolores River in
Colorado into the northern portion of the San Juan River Basin (U.S. Bureau of
Reclamation, 1977b). The water is released from a concrete diversion dam,
situated approximately 1.6 km downstream from the community of Dolores,
conveyed to the Montezuma Valley by main canal, and distributed for irrigation
purposes through an extensive series of canals and laterals. The MVIC reports
annual shortages of approximately 13 percent of irrigation requirements,
usually in the drier summer months.
Projected
In 1968, construction of the Dolores Project was authorized by the
Colorado River Basin Act as a participating project of the Colorado River
Storage Project (U.S. Bureau of Reclamation, 1977b). This project, located
within Montezuma and Dolores Counties, would divert w*ater from the Dolores
River to three different service areas, two of which are in the San Juan
Basin. These two areas, the Montezuma Valley, centered around Cortez, and the
Towaoc area, part of the Ute Mountain Ute Indian Reservation, would use the
diverted water for irrigation, municipal and industrial purposes, and fish and
wildlife (Table 16). Many square kilometers of land in the Towaoc area will
be brought under cultivation for the first time.
Releases from the outlet works of McPhee Dam will be made to the Dolores
River. Releases through the Great Cut Dike and the Dolores Tunnel will be
conveyed across the divide into the San Juan River Basin. Waters from the
dike will be routed via canal into Montezuma Valley and stored in Monument
Creek Reservoir. Waters passing through the Dolores Tunnel will be conveyed
via canal and pipeline to Towaoc and Cortez. The project area in the San Juan
55
-------
TABLE 16. WATER ALLOCATIONS FROM THE DOLORES PROJECT
Purpose
and
Location
Average Annual
Water Supply
(m3x!0°)
Land Area
(km2)
Irrigation
Full service
Dove Creek area
Towaoc area
Supplemental service
Montezuma Valley
Subtotal
66.978
28.247
16.899
112.124
112.75
30.35
106.43
249.53
Municipal and industrial use
Dolores Water Conservancy District
Cortez
Dove Creek
Rural areas
Towaoc Indian area
Subtotal
7.648
0.740
1.110
1.233
10.731
Fish and wildlife use
Released to Dolores River
Reserved for future use
Dolores Water Conservancy District
Ute Mountain Ute Indian Tribe
Subtotal
Total
31.331
0.987
0.987
33.305
156.160
249.53
Source: Modified from U.S. Bureau of Reclamation (1977b)
56
-------
Basin is drained by tributaries leading to Montezuma Creek, McElmo Creek, and
Navajo Wash, all of which depend primarily on irrigation return flows for
source waters.
The project would store and regulate the flows of the Dolores River for
utilization of 156.2 million m3/yr (U.S. Bureau of Reclamation, 1977b), of
which approximately 55.0 million m3 would reach the San Juan Basin
(Table 16). This amount imported into the San Juan Basin, in addition to the
existing MVIC annual commitments (Dick Gjere, 1977) for irrigation water,
would bring the upper basin a total of approximately 198.1 million m3 of
imported Dolores River water. However, the Dolores Project has not yet been
alloted the necessary Federal funds for development; it is not known how long
before the San Juan River Basin will realize the benefits of the additional
Dolores River water.
WATER AVAILABILITY VS. DEMAND
New Mexico was allocated 1,033.7 million m3/yr of consumptive use of
Colorado River water by the Colorado River and Upper Colorado River Compacts.
As noted earlier, the Bureau of Reclamation (1976a) estimates that only
896.7 million m3/yr is actually available for depletion by New Mexico in the
San Juan Basin; virtually all of this latter depletion allowance is presently
committed to existing and projected energy and irrigation projects in the
area.
Stockton and Jacoby's (1976) reconstructed flow records have indicated
that the period from 1907 to 1932 was the longest sustained period of high
flow in the Upper Colorado River Basin in the last 450 years (Figure 8). A
similar reconstruction of San Juan River flows and historical gaging records
indicate that since 1932 flow trends have been steadily downward and that
presently the Basin is experiencing its longest sustained period of low flows
of the past 360 years.
Superimposed on this "Jonah effect" (Mandelbrot and Wall is, 1968) are the
short-term variations. Flows in the San Juan Basin are highly variable with
daily flows at Bluff ranging from zero on several occasions in 1934 and 1939
to an excess of 320 m3/sec (USGS annual records). The construction of
Navajo Dam provides for some ability to regulate downstream flows; however,
the annual flows at Archuleta (below the dam) are only between 50 and 60
percent of those recorded at Bluff (USGS annual records).
Annual flows at Bluff, less than the authorized consumptive use
(896.7 million m3/yr), have been recorded on five occasions, including two
consecutive years since the completion of the Navajo Dam in 1962 (USGS annual
records). Fortunately, maximum consumptive uses generally occur during the
summer, the same times that maximum flows occur. However, only if no
commitment to in-stream flow requirements is recognized and recreational
demands are ignored, can there continue to be adequate water available to meet
authorized uses and downstream commitments. According to a Lake Navajo Marina
57
-------
COMPACT DRAFTED
cn
oo
x g
eo PR
S I
« ca
at-
15-
5'
J
/\ A /v r\ ^ f^ r\ f\ f~~\\ W-^
' | r i ' ! 1 ' '
1564 1600
1650
1700
1750
1800
1850
1900
1950
RECONSTRUCTED STREAMFLOW AT LEES FERRY BASED ON TREE-RING ANALYSES
Figure 8. Reconstructed streamflow at Lees Ferry based on tree-ring analyses.
-------
circular, the maximum storage capacity of Navajo Reservoir is 2,455 million
m^ of water, approximately one year's discharge of the San Juan past Bluff.
This buffer capacity should permit both authorized consumptive use and
sufficient discharge to Lake Powell to meet the Lower Colorado Basin
commitments.
There is, however, a developing collision course between water uses and
available water. It has been projected that, with all authorized diversions
active in the Basin, during a low water year the San Juan River will be dry
below Shiprock for many miles (U.S. Bureau of Indian Affairs, 1976). The
situation in the San Juan Basin is also affected by external factors involving
the Upper and Lower Colorado River and out-of-basin New Mexico demands.
Stockton and Jacoby (1976) show that for the Upper Colorado River Basin as a
whole "annual consumptive use will exceed annually renewable supply some time
before the year 2000."
59
-------
8. WATER QUALITY
SOURCES OF DATA
Available water quality information was used to assess the impact of
existing energy developments and irrigation projects in the San Juan River
Basin and to provide baseline data for determining the impact of proposed
developments. Most of the water quality data contained in this report were
obtained through the U.S. Environmental Protection Agency's computer-oriented
system for STOrage and RETrieval of water quality data (STORET). Other
sources of information include government documents and environmental impact
statements.
Ion composition, suspended sediments, nutrients, temperature,
conductivity, radionuclides, pH, and alkalinity data were primarily provided
by the U.S. Geological Survey (USGS) (Table 17, Figure 9). Trace element
concentrations were generally evaluated using data from the Colorado State
Health Department (Table 18, Figure 10). Data from other Federal and State
agencies in the basin were sporadic and provided little additional
information; they were generally not included in this report.
SUMMARY OF PHYSICAL AND CHEMICAL DATA
Summarized data for selected parameters provided by both the Federal and
State stations are included in Appendix B. Data are organized by parameter,
station number, and year for the period 1970-77. Data from 22 USGS stations
and from 13 Colorado State Health Department stations in the San Juan Basin
are presented. In general, for any given parameter, the annual arithmetic
mean for that parameter at each station is presented, along with the annual
minimum and maximum values and number of samples collected.
Arithmetic means for each parameter were calculated from all individual
sample values retrieved from STORET for a given year. When replicate
measurements were available for an individual sample, the mean for the
individual sample was used in calculating the yearly means. It should be
noted that no attempt was made to verify data retrieved from STORET; all
parameter measurements were accepted at face value with the exception of those
data that were obviously impossible (e.g., pH = 32) and were thus ignored.
60
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TABLE 17. U.S. GEOLOGICAL SURVEY SAMPLING STATIONS IN THE SAN JUAN RIVER BASIN
Station
Number*
STORET
Number
Station Name
Latitude/Longitude
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
09341200
09343000
09343300
09343400
09344300
09344450
09346000
09346400
09347200
09349800
09352900
09354500
09355500
09357300
09358900
09357500
09363500
09364500
09365000
09366500
09368000
09379500
Wolf Creek near Pagosa Springs, CO
Rio Blanco near Pagosa Springs, CO
Rio Blanco below Blanco Diversion, CO
Rio Blanco at U.S. Highway 84, CO
Navajo R. above Chromo, CO
Navajo R. below Oso Diversion, CO
Navajo R. at Edith, CO
San Juan R. near Carracas, CO
Middle Fork Piedra R. near Pago, CO
Piedra R. near Arboles, CO
Vallecito Creek near Bayfield, CO
Los Pinos R. at La Boca, CO
San Juan R. near Archill eta, NM
San Juan R. above Animas R., NM
Mineral Creek above Silver-ton, CO
Animas R. at Howardsville, CO
Animas R. near Cedar Hill, NM
Animas R. at Farnrington, NM
San Juan R. at Farmington, NM
La Plata R. at Co-NM state line
San Juan R. at Shiprock, NM
San Juan R. near Bluff, UT
37° 26' 47V106" 53' 00"
37° 12' 46"/106° 47' 38"
37" 12' 11"/106° 48' 45"
37° 08' 30"/106° 50' 24"
37* 01' 55"/106" 43' 56"
37° 01' 48"/106° 44' 16"
37° 00' 10"/106° 54' 25"
37° 00' 49"/107° 18' 42"
37° 29' 12"/107° 09' 46"
37° 05' 18"/107° 23' 50"
37° 28' 39"/107° 32' 35"
37° 00' 37'/107° 35' 49"
36° 48' 05"/107° 41' 51"
36° 43' 10"/108e 12' 45"
37° 51' 04"/107° 43' 31"
37° 49' 59"/107° 35' 56"
37° 02' 17V107" 52' 25"
36° 43' 12"/108° 12' 08"
36° 43' 22"/108° 13' 30"
36° 59' 59"/108° II1 17"
36° 47' 32"/108° 43' 54"
37° 08' 49"/109° 51' 51"
*Station numbers arbitrarily assigned for purposes of this report.
-------
ro
1C 0 ID 20 3O Kilometers
Figure 9. Location of U.S. Geological Survey sampling stations in the San Juan River Basin.
-------
TABLE 18. COLORADO STATE HEALTH DEPARTMENT SAMPLING STATIONS IN THE SAN JUAN RIVER BASIN
CO
Station
Number*
S-l
S-2
S-3
S-4
S-5
S-6
S-7
S-8
S-9
S-10
S-ll
S-12
S-13
STORE!
Number
000119
000102
000068
000069
000067
000081
000066
000104
000065
000103
000064
000063
000062
Station Name
San Juan R. below Pagosa, CO
Navajo R. near Chromo, CO
San Juan R. above Navajo Reservoir, CO
Pledra ft. NE of Arboles, CO
Los Pinos R. near La Boca, CO
Animas R. above Durango, CO
Animas R. near Bondad, CO
La Plata R. at Highway 160, CO
La Plata R. north of La Plata, CO
Mancos R. at Mancos, CO
Mancos R. 3 Miles north of
Stateline, CO
San Juan R. near Stateline, CO
McElnto Creek west of Cortez, CO
Latitude/Longitude
37° 15' OOV107" 00' 00"
37° 02' OOV1060 51' 00"
37° 01' OOV107" 13' 00"
37° 04' OOY1070 24' 00"
37° 00' OOV107" 35' 00"
37" 28' OOV107" 48' 00"
37" 04' OOV1070 52' 00"
37° 17' OOV1080 02' 00"
36° 58' OOV1080 18' 00"
37° 22' 00-/108" 16' 00"
37° 02' 00"/108° 44' 00"
37° 00' OOV1080 59' 00"
37° 20' OOV1080 46' 30"
*Station numbers arbitrarily assigned for purposes of this report.
-------
CD
37°00'
Sin Juan River
Basin
10 0 10 TO 30 Kilomttert
Figure 10. Location of Colorado State Health Department sampling stations in the San Juan River Basin,
-------
IMPACT OF DEVELOPMENT ON SURFACE WATER
Salinity
The Salinity Problem --
Salinity, the total concentration of ionic constituents, is the major
water quality parameter of concern in the San Juan Basin. Two processes
contribute to increases in salinity: salt loading and salt concentrating.
Salt loading, the addition of salts to the water system, is accomplished by
irrigation return flows, natural sources, and municipal and industrial wastes.
Salt concentrating, reduction of the amount of water available for dilution of
the salts already present in the river system, results from consumptive uses
of the water. Energy development in the San Juan Basin will primarily
influence salinity levels through the latter process.
The salinity problem in the Colorado River Basin, of which the San Juan
Basin is a part, has received much attention. In 1971 the Bureau of
Reclamation initiated the Colorado River Water Quality Improvement Program
(U.S. Bureau of Reclamation, 1976a). The purpose of the program is to promote
research and development of effective salinity control measures. The major
focus of the program is on four methods of salinity control: improvement of
irrigation efficiencies, structural controls, river and water systems
management, and utilization of return flows. In 1974, the Colorado River
Basin Salinity Control Act, PL 93-320, was passed providing for construction
of projects in the Colorado River Basin to control salinity levels (U.S.
Environmental Protection Agency, 1971). Methods of removing salt from the
McElmo Creek area are currently being studied as a result of this law.
Ambient Levels -- t .
Total dissolved solids (TDS) concentrations and conductivity levels
provide an indication of the dissolved constituents present in water. Values
for these two parameters (Appendix B), as well as concentrations of each of
the major cations (calcium, sodium, magnesium, potassium) and anions
(bicarbonate, sulfate, chloride), increase from upstream to downstream in the
San Juan River and its sampled tributaries (Figure 11). Surface water samples
from Wolf Creek near Pagosa Springs, Colorado, and the San Juan River near
Bluff Utah showed an increase in average TDS concentrations from 42 mg/1 to
615 mg/1 and an average conductivity increase from 52 umho/cm to 808 umho/cm
during 1975. The average dissolved solids from these two areas provides a
further indication of the amount of salt Increase: in the San Juan River near
Pagosa Springs, lorns et al. (1965) calculated an average TDS loading of
25,400 kg/day, while near Bluff the calculated average was 2,476,600 kg/day.
Additional baseline information on TDS loadings from various locations is
presented in Table 19.
Calcium is the major cation in the basin followed by sodium, magnesium,
and notflssium The most abundant anion in the upper basin is the bicarbonate
ion- in the Tower basin, the sulfate ion predominates (Figure 11). Chloride
concentrations ?n tnTbasin are low, and the carbonate ion (C03) Is usually
65
-------
WOLF CREEK NEAR PAGOSA SPRINGS
42
SAN JUAN RIVER NEAR ARCHULETA
176
SAN JUAN RIVER ABOVE ANIMAS RIVER
287
ANIMAS RIVER AT FARMINGTON
383
LEGEND
Ca
Mg
HCOg
:i
SO 4
(mg/llter)
SAN JUAN RIVER AT FARMINGTON
>
280
SAN JUAN RIVER AT SHIPROCK
>
360
SAN JUAN RIVER AT BLUFF
(mg/liter-CATIONS) 200 150 100 50 0 50 100 150 200 (mg/llter-ANIONS)
Figure 11. Distribution of major cations and anions at selected stations
in the San Juan River Basin, 1975.
66
-------
TABLE 19. WATER AND DISSOLVED SOLIDS DISCHARGE IN THE SAN JUAN BASIN*
Stations
San Juan River near Pagosa Springs, CO
West Fork San Juan River above Borns
Lake near Pagosa Springs, CO
San Juan River at Pagosa Springs, CO
Navajo River at Edith, CO
San Juan River near Arboles, CO
Piedra River near Piedra, CO
San Juan River at Rosa, NM
Los Pinos River near Bayfield, CO
Los Pinos River at La Boca, CO
San Juan River near Blanco, NM
An i mas River at Howardsville, CO
Mineral Creek near Silverton, CO
Animas River at Duranyo, CO
An i mas River at Farmington, NM
La Plata River at Hesperus, CO
La Plata River at Colorado-New Mexico
State line
La Plata River near Farmington, NM
San Juan River at Shiprock, NM
Mancos River near Towaoc, CO
McElmo Creek near Cortez, CO
San Juan River near Bluff, UT
Drainage Area
(Km2)
225.1
106.7
771.8
427.4
3,470.6
960.9
5,154.1
735.6
1,320.9
9,220.4
144.8
113.7
1,792.3
3,522.4
95.8
857.3
1,510.0
33,411.0
1,424.5
603.5
59,570.0
Water
Discharge
Mean Mean Annual
(n3/sec) (m3X106)
3.823
2.506
11.413
4.644
21.183
10.762
34.210
11.243
7.873
43.018
3.313
2.974
24.327
27.499
1.368
1.090
0.889
75.869
1.767
1.515
79.296
120.635
79.079
360.179
146.539
668.428
339.580
1,079.427
354.752
248.425
1,356.839
104.551
93.832
816.940
867.760
43.160
34.402
28.062
2,394.204
55.766
47.810
2,501.518
Dissolved Solids
Weighted-Average Mean Discharge
Concentration (mg/1) (kg/day)
77
42
73
113
104
126
117
62
108
125
111
78
183
233
84
356
908
256 1
629
2,180
361 2
25,400
9,070
71,870
45,360
191,410
117,030
347,450
59,880
73,480
464,480
31,750
19,950
385,550
554,290
9,980
33,560
69,850
,678,283
96,160
285.760
,476,600
*Water and dissolved solids discharge from the water years 1914-57 are adjusted to 1957
water use conditions.
Source: Modified from lorns et al. (1965).
-------
not detected in the surface waters (Appendix B). In 1975 between Pagosa
Springs and Bluff, average calcium concentrations increased from 5.8 to
81.7 mg/1, sodium from 3.1 to 76.6 mg/1, magnesium from 0.6 to 29.9 mg/1,
potassium from 1.0 to 3.2 mg/1, bicarbonate from 21 to 165 mg/1, sulfate from
4 to 315 mg/1, and chloride from 0.9 to 16.5 mg/1 (Appendix B).
Irrigation of the gypsum-rich soils near the Colorado-New Mexico State
line is responsible for the upper to lower basin shift in anion dominance
(U.S. Environmental Protection Agency, 1971). This bicarbonate-sulfate syste
in the basin is particularly noteworthy since sulfate generally has a more
negative impact on beneficial uses than equivalent amounts of bicarbonate.
Bicarbonate is usually the most abundant anion in fresh water systems and
plays an important role in buffering; sulfate ion dominance can lead to
acidity problems through sulfuric acid formation (Hutchinson, 1957).
Both the concentrations and composition of dissolved solids in the
San Juan River alter with flow. Ion concentrations tend to increase as flow
decreases while chemical composition generally shifts from calcium bicarbonat
dominance during high flow periods to calcium sulfate dominance during medium
and low flows when ground-water discharge is a greater component of the base
flow (lorns et al., 1965). Fluctuations in flow play a major role in the
large seasonal variations of dissolved solids concentrations observed at
Bluff.
Yearly concentrations of the major ions, IDS, and conductivity values wer
variable from 1970 to 1976 (Appendix B). No significant increase or decrease
in these parameters was noted over this period. IDS values from 1941-68 in
the San Juan River stations near Archuleta, New Mexico, and Bluff, Utah, also
show a large amount of variation (Tables 20 and 21). Again, flow fluctuation
are influential in creating these differences. The effect of Navajo Dam,
which began storage on July 1, 1962, can be seen at the Archuleta station in
particular.
Silica (Si02) is probably present in the form of undissociated silicic
acid. No general spacial or temporal trend is evident for this species
(Appendix B). It does, however, appear to be more prevalent in the Rio
Blanco-Navajo River area than further downstream. Silica concentrations in
the basin ranged from a minimum of 1.3 mg/1 to a maximum of 37.0 mg/1.
The composition of dissolved solids in the waters of the San Juan Basin
varies with local geology as well as with flow (Figures 12-14). The ionic
composition of the headwaters of the East and West Fork of the San Juan, and
the Navajo, Piedra, and Los Pinbs Rivers is mainly calcium bicarbonate with
low concentrations of dissolved solids. Although the headwaters of the Anima
River are also in the San Juan Mountains, as are the headwaters of the above-
mentioned tributaries, their ion composition is calcium sulfate during mediun
and low flows and calcium bicarbonate during high flows. Chaco River samples
suggest sodium sulfate ion composition (lorns et al., 1965). The dominant
cation-anion combination in the headwaters of the La Plata River is of the
calcium bicarbonate type. From Hesperus, Colorado, to the mouth of this
river, irrigation effects are reflected in the high concentrations of
dissolved solids and calcium sulfate waters (lorns et al., 1965). Data from
68
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TABLE 20. ANNUAL SUMMARY OF FLOW AND TOTAL DISSOLVED SOLIDS DATA,
1941-68, IN THE RIVER NEAR ARCHULETA, NEW MEXICO
Year
1941
1942
1943
1944
1945
1946
1947
x •* i /
1948
A *J~ \j
1949
1950
JL •* w V
1951
X ^/ W A
1952
J. J V (•
1953
±•7 w w
1954
1955
±3 \J
-------
TABLE 21. ANNUAL SUMMARY OF FLOW AND TOTAL DISSOLVED SOLIDS DATA,
1941-68, IN THE SAN JUAN RIVER NEAR BLUFF, UTAH
Year
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
Total
Mean
_L. r~ ^ t _ • _
Discharge
(m3X106)
6,042.868
2,771.652
1,842.834
2,825.926
1,958.782
1,094.106
2,068.563
2,639.669
3,067.690
1,053.400
852.342
3,150.333
1,192.785
1,247.058
1,122.470
1,033.665
3,588.222
2,834.560
878.245
1,982.218
1,559.131
1,825.565
714.191
980.624
3,140.465
1,909.442
975.690
1,307.499
55,659.995
1,488.386
TDS Concentration*
(mg/D
394
388
472
353
433
564
476
335
345
498
579
333
533
566
539
469
378
357
597
387
486
436
806
722
398
473
772
606
439
(kg/m3)
0.39
0.39
0.47
0.35
0.43
0.56
0.48
0.34
0.34
0.50
0.58
0.15
0.53
0.51
0.54
0.47
0.38
0.36
0.60
0.39
0.49
0.44
0.81
0.72
0.40
0.47
0.77
0.61
0.44
TDS Loading
(kg x 106)
2,381.348
1,075.008
869.986
998.805
848.213
617.790
986.104
885.408
1,059.586
525.257
493.506
1,048.700
635.933
706.693
605.089
485.341
1,358.956
1,012.413
524.350
768.381
758.402
795.597
576.059
708.508
1,251.001
903.551
753.866
792.875
24,426.726
872.707
Source: Modified from U.S. Department of Interior (1971).
70
-------
ToUl Ois*olv«d Solids lmg/1) -
Conductivity | Mato/em]/
^V""'*/' -»1^
i >
Figure 12. Mean total dissolved solids (mg/1) and conductivity (pmho/cm), 1973, at
U.S. Geological Survey sampling stations in the San Juan River Basin (Appendix B)
-------
Calcium/TX Magnesium
i 7.1 1 0.6 \
Sodium
37=00'
ro
10 Q 10 2O 3O Kilometers
Figure 13. Mean calcium, sodium, magnesium, and potassium concentrations (mg/1), 1973, at
U.S. Geological Survey sampling stations in the San Juan River Basin (Appendix .).
-------
BIcirbonite/jsJASulfite
Chloride
37°00'
GO
Figure 14. Mean bicarbonate, sulfate, and chloride concentrations (mg/1), 1973, at U.S.
Geological Survey sampling stations in the San Juan River Basin (Appendix B)
-------
this USGS tributary station show higher levels of calcium, bicarbonate,
sulfate, magnesium, IDS, and conductivity than any other sampling site in the
Basin.
The chemical composition of the dissolved ions in the Mancos River is
mainly calcium bicarbonate during spring runoff, but the river contains larger
amounts of magnesium and sulfate in the fall as a result of irrigation (lorns
et al., 1965). Ionic composition of irrigation water imported to the McElmo
Creek Basin from the Dolores River area is primarily calcium bicarbonate in
nature and low in dissolved solids. The Creek itself, however, contains high
TDS concentrations, primarily magnesium sulfate in composition but with large
percentages of calcium and sodium from irrigation return flows (lorns et al.,
1965). The headwaters of Montezuma Creek are low in dissolved solids with
calcium bicarbonate ion composition. The main cation-anion combination in the
surface waters of the San Juan River near Archuleta is calcium bicarbonate,
while at Bluff calcium sulfate predominates except during spring runoff when
bicarbonate replaces sulfate as the main anion (lorns et al., 1965). High
concentrations of dissolved solids are present at this station.
Sources--
Mining increases TDS levels primarily through salt-loading processes.
Observations of the chemical characteristics of water, spoil, and overburden
in the Navajo Mine area (Table 22) suggest that runoff from mine spoils will
contain higher concentrations of dissolved solids than runoff from undisturbed
ground. Sodium and chloride concentrations, especially, will be greater in
runoff from fresh spoils (McWhorter et al., 1975). The data presented,
however, come from a limited area, and their application to the Navajo Mine as
a whole has not been determined. Since precautions have been taken to control
surface flow, discharge from the Navajo Mine area is primarily through deep
percolation, and dissolved solids pickup has been roughly estimated at
1,400 kg per hectare (McWhorter et al., 1975). Actual pickup from the mining
operations is less since TDS contributions from the soil in this area are
probably high.
The high concentrations of dissolved solids recorded in Shumway Arroyo
may, in part, be due to the Fruitland Coal Mine and San Juan Powerplant.
Average concentrations of salinity-related parameters in USGS samples from
1974 to 1975 were as follows: calcium--387 mg/1; magnesium—243 mg/1;
sodium—1,016 mg/1; potassium—15 mg/1; sulfate—3,422 mg/1; bicarbonate—
112 mg/1; chloride—344 mg/1; TDS—5,576 mg/1; and conductivity—6,278 mg/1
(Appendix B).
The active mine at Gladstone was responsible for a large portion of the
high TDS concentrations in the Upper Animas Basin (over 1,000 mg/1 in Cement
Creek during the 1965-66 study period) although abandoned mines also
contributed to the problem (U.S. Environmental Protection Agency 1971) At
Shiprock 9,980 kg/day of dissolved solids were added by seepage from tailing
ponds located on the site of the Vanadium Corporation of America's uranium
?1U; /lowing oil-test holes in the vicinity of Four Corners contributed
4,535 kg/day of dissolved solids to the river (U.S. Environmental Protection
Agency, 1971).
74
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TABLE 22. MEAN CHEMICAL CHARACTERISTICS OF WATER, SPOIL, AND
OVERBURDEN, NAVAJO MINE, 1973
Parameter
pH
Dissolved solids, mg/1
Specific cond., nmhos/cm
Calcium, mg/1
Magnesium, mg/1
Sodium, mg/1
Potassium, mg/1
Bicarbonate, mg/1
Chloride, mg/1
Sulfate, mg/1
Copper, mg/1
Dissolved iron, mg/1
Manganese, mg/1
Zinc, mg/1
Lead, mg/1
Aluminum, mg/1
Nitrate, mg/1
Spoils Overburden
8.0 8.1
-
3960 9390
31 40
212 229
622 1800
27 36
149 607
30 32
768 1490
-
-
_
_
-
_
-
Pit
Water
8.7
-
17300
-
19
5000
64
-
1850
-
<0.9
-
-
0.02
<0.1
<0.5
20
Shallow
Wells
7.7
2609
-
153
31
631
11
347
53
1384
<0.1
0.1
0.4
0.2
<0.1
-
~
Pictured
Cliff
Aquifer
7.8
47000
-
170
73
18700
290
3270
24200
17
<0.1
<0.1
<0.01
-
<0.01
-
Source: Modified from McWhorter et al. (1975)
75
-------
The Four Corners Powerplant increases IDS concentrations in the San Juan
River at Shiprock by 54 mg/1 through both salt-loading and salt-concentrating
processes. Seepage from ash disposal sedimentation ponds contributes
31,750 kg of dissolved solids per day, while blowdown of Morgan Lake
contributes 8,618,210 kg annually (U.S. Environmental Protection Agency,
1971). In addition, diversion of water for the plant reduces the annual flow
at Shiprock by approximately 2 percent (U.S. Bureau of Reclamation, 1976b).
The WESCO and EL Paso Gasification Plants would increase salinity levels
in the river by decreasing water quantity. The WESCO Project would reduce
available water by approximately 3 percent. At Shiprock the increase in TDS
levels attributable to this plant would be 7.1 mg/1 in 1981 and 14.0 mg/1 in
2005 (U.S. Bureau of Reclamation, 1975). The El Paso Plant would reduce flow
by less than 2 percent and would increase TDS levels by 2.4 mg/1 in 1981 and
by 8.5 mg/1 by 2005 (U.S. Bureau of Reclamation, 1977c).
An estimated TDS increase of 228 mg/1 by the year 2005 is expected as a
result of the gasification plants, the Four Corners and San Juan Powerplants,
and the Navajo Indian Irrigation Project (Table 23). The irrigation project
would be responsible for about 80 percent of this increase (U.S. Bureau of
Reclamation, 1976b).
Irrigation is a major contributor to salinity through both salt-loading
and salt-concentrating processes. Leaching of salts from the soil is
particularly pronounced in the early years of irrigation when large amounts of
salt residing in the soil are first exposed to water. This process continues
until a balance is reached between the amount of salts carried off and the
amount added. However, in soils derived from marine-deposited shale, such as
the Mancos Shale in parts of the San Juan region, continuous salt pickup
results (Upper Colorado Region State-Federal Inter-Agency Group, 1971d). The
salt-concentrating effects of irrigation result from loss of water through
evaporation, transpiration, and seepage. The problem becomes especially acute
when excessive amounts of water are diverted for irrigation.
At Bluff, progressive, small salinity increases are anticipated as a
result of the Navajo, Hammond, and Florida Projects. Changes in water quality
from these three projects are not expected to significantly impact irrigation
or municipal costs in the basin (U.S. Environmental Protection Agency, 1971).
The Navajo Indian Irrigation Project will increase salt loading in the San
Juan River by approximately 15.1 million kg (U.S. Bureau of Indian Affairs,
1976). The Dolores River Project would add about 24.8 million kg each year.
Salt increases from project uses would account for about 37 percent of this
addition while the remaining 63 percent would come from the Dolores River
diversions (U.S. Bureau of Reclamation, 1977b).
Man's activities, then, have had a major impact on salt levels in the San
Juan River Basin. lorns et al. (1965) estimated that without man's influence
the weighted average concentration of TDS in the San Juan River for the water
years 1914-57 (adjusted to 1957 water use conditions) would have been
228 mg/1 as compared with the actual value of 361 mg/1. The average TDS
76
-------
TABLE 23. CUMULATIVE IMPACTS OF MAJOR WATER USERS ON TOTAL DISSOLVED SOLIDS IN THE
SAN JUAN RIVER BASIN BASED ON 1974 USERS*
Without Projects Active
Flow Concentration IDS
(106m3/yr) (mg/1) <106kg/yr)
Inflow to Navajo Reservoir 1,271.7 177 224.1
Navajo Reservoir evaporation
Diversion to Navajo Indian
Irrigation Project
San Juan River at diversion
to El Paso Gasification Plant 1,227.3 201 245.8
Diversion to El Paso Gasifi-
cation Plant
Navajo Indian Irrigation Project
return
San Juan River at diversion to
UESCO Gasification Plant 1,726.9 393 676.8
Diversion to UESCO Gasification
Plant
Diversion to Four Corners
Powerplant
Four Corners Plant return
Diversion to San Juan Powerplant
Navajo Indian Irrigation Project
return
San Juan River at Shiprock
New Mexico 1,850.2 408 753.0
Net change resulting from cumulative impact =
Colorado River at Lees Ferry,
Arizona 11.909.3 641 7,620.3
Net change resulting from cumulative Impact -
With All Projects Active 1n Year 2005
River Diversion Return
Flow Flow Flow Concentration
(lO^/yr) (lO^/yr) (loV/yr) (mg/1)
1,271.7 177
32.1 0
407.1 181
788.2 219
34.5 219
96.2 2140
1,349.4 596
43.2 596
64.1 596
16.0 Unknown
19.7 596
32.1 2090
1,393.8 636
-456.4 +228
( -25*) (+56%)
11,452.3 678
-457.0 +37
(-«) (+6X)
IDS
(I06kg/yr)
224.1
0
73.5
172.4
7.3
205.9
801.9
25.4
33.1
Unknown
11.8
67.1
884.5
+131.5
(+17J)
7,751.9
131.5
(+z»)
*Inputs of tributaries and impacts of municipal and other sources not shown.
Source: Modified from U.S. Bureau of Reclamation (1977).
-------
concentration at Shiprock in 1974 (without consideration of major water users)
was 408 mg/1 and is expected to increase to 636 mg/1 with all major users
active in year 2005 (U.S. Bureau of Reclamation, 1977c). In both estimations,
approximately one-third of the dissolved solids concentration in the river
results from man's activities. Loadings attributable to the various salinity
sources from the headwaters of the San Juan River to Shiprock have been
calculated by the EPA (1971) and are shown in Table 24.
TABLE 24. SALT LOADINGS ATTRIBUTABLE TO VARIOUS SOURCES ALONG THE
SAN JUAN RIVER BETWEEN THE RIVER HEADWATERS AND SHIPROCK,
1965-66
Source
Loadings
kg/day X 103 (tons/day)
Percent
Total Load
Mine drainage
Irrigation
Mineral springs
Runoff
Municipal effluents
Industrial effluents
Total
13.608 (15)
328.400 (362)
22.679 (25)
940.746 (1,037)
9.071 (10)
41.730 (46)
1356.234 (1,495)
1.0
24.2
1.7
69.3
0.7
3.1
100.0
Source: Modified from U.S. Environmental Protection Agency (1971).
Impact—
The EPA water quality criteria for chlorides and sulfates (Table 25) in
domestic water supplies is 250 mg/1 (U.S. Environmental Protection Agency,
1976c). These standards have been periodically exceeded in the Animas River
(Appendix B) at Farmington, in the La Plata River, and in the San Juan River
stations near Farmington, Shiprock, and Bluff. They are commonly exceeded in
the Chaco River, which has naturally poor water quality not recommended for
human consumption (U.S. Bureau of Reclamation, 1976b). Values greater than
the standard have also been reported in the Mancos River and McElmo Creek
(U.S. Bureau of Reclamation, 1977b). The sulfate criterion of 250 mg/1 was
imposed because of the anion's cathartic effect especially when associated
78
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TABLE 25. WATER QUALITY CRITERIA RECOMMENDED BY THE NATIONAL ACADEMY OF SCIENCE (1973)*
Parameter
(Total Form)
Aluminum
Arsenic
Barium
Beryl 1 1 um
Boron
Cadml urn
Chlorides
Chromium
Copper
Cyanide
Dissolved oxygen
Fluoride
Iron
Lead
Lithium
Manganese
Mercury
Molybdenum
Nickel
Nitrate nitrogen
Nitrite nitrogen
pH
Selenium
Silver
Sul fates
Vanadium
Zinc
Drinking Water
(mg/1)
O.OBf
l.Of
O.Olf
250ft
O.OSf
i.ott
0.2
1.4-2. 4t
0.3ft
0.05|
--
0.05ft
0.002t
__
lO.Ot
1.0
5.0-9.0
O.Olt
0.05t
250tt
5. Ott
Livestock
(ing/1)
5.0
0.2
5 0
0.05
1.0
0.5
2.0
0.05-0.1
0.01
—
100.0
10.0
0.05
--
—
0.1
25.0
Aquatic Life
(mg/l)
_.
0.011-1. 100ft
0.0004-0.012tt
O.ltt
AFttt
0.006ft
R 0
1.0ft
0.03
0.05 pg/lff
AFttt
~~
6.5-9.0
"
— —
AFttt
Irrigation
(mg/D
5.0
o.in
0.1-0.5ft
0.75tt
0.01
0.1
0.2
1.0
5.0
5.0
2.5
0 2
0.01
0.2
0.02
01
2.0
*Those parameters for which drinking water regulations (1975) or quality criteria (1976c)
have been established by the U.S. Environmental Protection Agency replace the older NAS
recommended levels and are so indicated.
tU.S. Environmental Protection Agency (1975).
ttu.S. Environmental Protection Agency (1976c).
fttAF = Application Factor. Indicates criterion for this parameter must be separately established
for each water body.
-------
with magnesium and sodium. Furthermore, water taste can be affected by
concentrations in excess of 300 to 500 mg/1 (U.S. Environmental Protection
Agency, 1976c).
A table of water hardness in the San Juan Basin is presented in
Appendix B. Sawyer's classification of water according to hardness content
(U.S. Environmental Protection Agency, 1976c) is seen on Table 26.
TABLE 26. SAWYER'S CLASSIFICATION OF WATER ACCORDING TO
HARDNESS CONTENT
Concentration Description
of CaCOa (mg/1)
0-75 Soft
75 - 150 Moderately hard
150 - 300 Hard
300 and up Very hard
Source: Modified from U.S. Environmental Protection Agency (1976c).
The headwaters of the Rio Blanco, Navajo River, Piedra River, and Los
Pinbs River are soft according to this classification. The Animas River
progresses from moderately hard at its headwaters to hard near Farmington. La
Plata. River waters are very hard. The San Juan River' is moderately hard near
Archuleta, hard at Farmington and Shiprock, and hard to very hard at Bluff.
High salinity concentrations and hard water have several adverse effects on
municipal needs aside from lowering drinking water quality. If water
softening is not practiced, soap and detergent consumption increases resulting
in increased nutrients and other environmental pollution, and higher treatment
costs to the community. Where water softening is practiced, treatment costs
rise with the degree of hardness. Dissolved solids and hardness also play a
role in corrosion, scaling of metal water pipes and heaters, and acceleration
of fabric wear (U.S. Environmental Protection Agency, 1971).
Descriptions of the impact of total dissolved solid concentrations on
irrigation waters in arid and semiarid areas is presented in Table 27 (U.S
Environmental Protection Agency 1976c); TDS values for waters in Rio Blanco,
Navajo River, Piedra River, and Los PirTos River (Appendix B) are not known to
exceed the 500 mg/1 level. The Animas River water is generally good for
80
-------
irrigation although values above 500 mg/1 have been recorded at the Farmington
station. Values in the La Plata River usually range from 500 to 1,000 mg/1.
Mean IDS values in the San Juan River are generally under 500 mg/1 except at
Bluff where tney are slightly higher. Values over 1,000 mg/1 have been noted
at the San Juan station directly above the Animas River and at the
Farmington, Shiprock, and Bluff stations.
Excessive salinity in irrigation water reduces crop yields, limits the
types of crops grown in an area, and can affect soil structure, permeability,
and aeration (U.S. Bureau of Reclamation, 1975). Salt adversely impacts
plants primarily by decreasing osmotic action and thereby reducing water
uptake.
TABLE 27. TOTAL DISSOLVED SOLIDS HAZARD FOR IRRIGATION WATER
Description TDS
(mg/1)
Water from which no detrimental effects will 500
usually be noticed
Water that can have detrimental effects on 500-1,000
sensitive crops
Water that may have adverse effects on many crops 1,000-2,000
and requires careful management practices
Water that can be used for tolerant plants on 2,000-5,000
permeable soils with careful management practices
Source: Modified from U.S. Environmental Protection Agency (1976c).
The effects of salinity on irrigation are determined, not only by the
total amount of dissolved solids present, but also by the individual ion
composition of the water (Utah State University, 1975). Certain plants are
sensitive to high concentrations of sulfates and chlorides. Large amounts of
calcium can inhibit potassium uptake. Sodium causes plant damage at high
concentrations because it increases osmotic pressure and is toxic to some
metabolic processes. It can also affect soils adversely by breaking down
granular structure, decreasing permeability, and increasing pH values to those
of alkaline soils. In 1954 the U.S. Salinity Laboratory proposed that the
sodium hazard in irrigation water be expressed as the sodium absorption ratio
(SAR): SAR = Na///2(Ca + Ng) where Na, Ca, and Mg are expressed as
81
-------
concentrations in milliequivalents per liter of water (McKee and Wolf, 1963).
Sodium is present in low concentrations in the San Juan Basin except in some
of the intermittent streams to the south and in some springs (lorns et al.,
1965). However, large scale use of sodium chloride water softeners in the
basin could alter the ionic composition and increase sodium levels to damaging
concentrations.
Industrial users may be severely affected through use of water for cooling
or washing purposes that is high in total dissolved solids. Such water may
result in corrosion and encrustation of the metallic surfaces of pipes,
condensers, or other machinery parts. However, industrial requirements for
purity of water vary considerably (Table 28). Examination of IDS levels in
headwater tributaries of the San Juan Basin (Appendix B) indicates that most
industrial needs could be met in that region without any water treatment
efforts. However, in the lower portion of the Basin, some form of
de-ionization treatment would be required for some uses (lorns et al., 1965).
Such treatment is expensive (U.S. Environmental Protection Agency, 1976c);
this expense could be a primary factor limiting future industrial advancement
in the San Juan Basin.
TABLE 28. MAXIMUM TOTAL DISSOLVED SOLIDS CONCENTRATIONS OF SURFACE WATERS
RECOMMENDED FOR USE AS SOURCES FOR INDUSTRIAL WATER SUPPLIES
Industry/Use Maximum Concentration (mg/1)
Textile 150
Pulp and paper 1,080
Chemical 2,500
Petroleum 3,500
Primary metals 1,500
Copper mining 2,100
Boiler makeup 35,000
Source: Modified from U.S. Environmental Protection Agency (1976c).
82
-------
The impact of salinity on fish and wildlife is highly variable.
Many fish, for example, tolerate a wide range of total dissolved solid
concentrations; the whitefish reportedly can survive in waters containing
TDS levels as high as 15,000 mg/1, and the stickleback can survive in
concentrations up to 20,000 mg/1. Reproduction and growth may be
significantly affected during stress periods, however. The EPA (1976c)
reports that, generally, water systems with TDS levels in excess of
15,000 mg/1 are unsuitable for most freshwater fish. In the San Juan Basin,
TDS levels are well below this recommended maximum figure.
Toxic Substances
Trace elements —
The primary sources of trace elements in the San Juan Basin are mine
drainage and surface runoff after thunderstorms (U.S. Bureau of Reclamation,
1975). A major problem area is the Animas River where pollution from mines in
the headwaters, particularly at Cement and Mineral Creeks, is responsible for
high concentrations of trace elements. Elimination of aquatic organisms also
occurred in the headwaters of the Mancos River as a result of natural mineral
seepage (U.S. Department of Interior, 1971).
Energy development may influence trace element levels in several ways.
Reduction of water quantity from the developments and irrigation projects may
result in increased trace element concentrations in the basin waters.
Additional trace elements may be added to the river through runoff from strip
mine tailings and coal storage. Furthermore, trace elements in stack
emissions from coal-fired plants may be deposited in the drainage basin and
can then reach the river through runoff. Atmospheric emissions from the
proposed gasification plants will probably be too low to have much effect on
most heavy metal levels (U.S. Bureau of Reclamation, 1975 and 1977c). Ash
pond seepage from the Four Corners Plant does not appear to be a problem at
this time in relation to heavy metals, probably because of clay particle
adsorption of the metals (U.S. Bureau of Reclamation, 1976b). However,
changing environmental conditions, such as fluctuating flows or discharges of
strongly acidic wastes, could result in release of these elements at a later
date.
Mercurv concentrations in surface water samples in 1971 exceeded the EPA's
recommended standards for aquatic life (Table 25) at stations in the San Juan,
recommended stanaaras H and Mancos R1yers (Append1x B ^ ^
c^SSfriiSn™*" especially high in the latter two tributaries The EPA
(1976c) aquatic life standard of 0.05 yg/1 for mercury in water was
established to insure safe levels in edible fish.
The mean mercury concentration of 34 sediment samples collected by the
EPA EMSL Las^eSas throughout the Basin in 1977 was 0.064 yg/g. However, a
sediment samoleCollected above Navajo Reservoir contained 40 yg/g and one
f±McElmoTreek con ined 80 yg/g (analytical error for these samples was
83
-------
estimated to be ±30 percent because of the high mercury concentrations).
These two samples were not included in determining the mean. Both of these
samples contained visible amounts of oil or tar; whether this was the source
of the high values, served to concentrate the mercury, or was merely
coincidental was not determined.
A 1970 study (Southwest Energy Study, 1972a) showed the mercury
concentrations in fish in Navajo Reservoir to be among the highest in the
Southwest. Brown trout contained 1.4 yg/g mercury and chubs contained
8.9 yg/g. The EPA analyzed fish flesh from the San Juan arm of Lake Powell in
1977 and detected th.e following mercury concentrations: 6.0 yg/g in a carp,
0.415 yg/g in a crappie, 0.34 yg/g in a cutthroat trout, and 0.26 yg/g in a
dace. These values were comparable to those found in Lake Powell by
Standiford et al. (1973). Bioconcentration of mercury is well documented.
High concentrations of the element in aquatic life pose a serious health
threat to the human consumer; the U.S. Food and Drug Administration has
recommended that consumption of fish containing mercury levels in excess of
0.5 ppm (yg/g) be restricted for the maintenance of public health (Lambou,
1972). In 1970, the New Mexico Environmental Improvement Agency issued
warnings to the public to limit the eating of fish found in several New Mexico
impoundments including Morgan Lake and Navajo Reservoir (Southwest Energy
Study, 1972b).
Mercury-bearing sedimentary rock is probably the main source of this
element in the river system (Standiford et al., 1973). Power generation
facilities may also affect mercury levels. Currently mercury emissions from
the Four Corners Powerplant are approximately 562 kg/yr (U.S. Bureau of
Reclamation, 1976b); an estimated 55 g of mercury are deposited annually in
Navajo Reservoir and 580 g are deposited in the drainage basin from this
source. Projected increases of loadings from regional powerplants would only
elevate mercury levels from 1 to 5 percent above ambient concentrations (U.S.
Bureau of Reclamation, 1976b). However, with the high ambient levels in the
area, this may be enough to raise concentrations above criteria recommended by
the EPA (1976c).
Concentrations of iron in the San Juan Basin waters are highly variable
(Appendix B). Iron levels at the sampling sites during the 1970-76 study
period were generally greatest in 1975, followed by 1976 values. Iron
periodically exceeds the EPA criterion for drinking water at each of the
stations with the exception of the upper La Plata location. The criterion was
established to prevent objectionable taste and laundry staining (U.S.
Environmental Protection Agency, 1976c). The EPA standard for aquatic life
was exceeded at all but the upstream stations in the La Plata and Mancos
Rivers. High concentrations of iron can be fatal to aquatic organisms. Mine
drainage, ground water, and industrial wastes are major sources of iron
pollution.
Manganese concentrations are also highly variable (Appendix B). This
element was detected yearly in the Animas River above Durango. It was never
found in the Upper Mancos River site. At the other 10 stations, its
occurrence during the period from 1970 to 1974 was rare. However, in 1975 and
1976 the element was detected at each of these stations.
84
-------
Manganese concentrations periodically exceeded the EPA standards for
domestic water supplies at all but the upstream stations of the Mancos and
La Plata Rivers (Appendix B) . The 50.0 pg/1 criterion was established to
minimize staining of laundry and objectionable taste effects. The
objectionable qualities of manganese may increase in combination with low
concentrations of iron (U.S. Environmental Protection Agency, 1976c).
Concentrations of various other trace elements at selected Colorado State
Health Department stations are presented in Appendix B. Chromium (valence
of 6) and silver were not detected at any of the State stations. Arsenic,
cadmium, copper, and molybdenum were rarely detected. However, USGS data
commonly indicate cadmium values in excess of the EPA criteria for drinking
water and aquatic life throughout the Basin, and chromium in excess of the
same criteria in the downstream stations. Other sources (Upper Colorado
Region State-Federal Inter-Agency Group, 1971d) also report that arsenic
levels in the Animas River have exceeded the 1975 EPA drinking water
regulations. Boron was detected at each sampling site. Maximum values at
State stations in the Animas River near Bondad, Colorado, and McElmo Creek
west of the State line exceeded EPA standards for irrigation waters (Table
24). Maximum lead and selenium concentrations exceeded EPA drinking water
criteria at the McElmo Creek station and the San Juan site near the State
line. Zinc levels never exceeded the 5,000 yg/1 criterion for domestic water
supplies. Concentrations of cyanide in the Animas River and McElmo Creek have
periodically exceeded water standards (Upper Colorado Region State-Federal
Inter-Agency Group, 1971d; U.S. Bureau of Reclamation, 1977b).
The effects of elemental emissions upon soil, flora, and fauna in the Four
Corners area have been investigated (Conner et al., 1976; Southwest Energy
Study 1972b; Westinghouse Environmental Services Division, 1975;
Environmental Studies Laboratory, 1974) with few definitive results. No
direct damage to vegetation in the area was observed by University of Utah
investigators (Environmental Studies Laboratory, 1974). Conner et al . (1976)
report that "soil chemistry in this area shows no obvious geochemical features
that could be attributed to the presence of the powerplant. Vegetation
chemistry however, points to a large number of suspect elements. . . ." Of
these, calcium, magnesium, and silicon are probably correlated with soil
changes while potassium, sodium, and sulfur are hard to explain ... but do
not appear to involve, in a simple way, simple element contamination from
either nature (soil dust) or man (stack emissions). Of the remaining nine
susoect elements, the strongest trends in vegetation are in fluoride and
selenium trends for cobalt and strontium are fairly strong, and ...
must be considered as suspect pollutants." Trends in molybdenum, nickel,
gallium, lithium and boron are probably substrate controlled. Conner et al .
Mq7^ nntPdthat similar results were obtained near the Dave Johnson
Powerilant In Kyomfng, lending credence to the view of these elements as
pollutants.
FnH-.mai-Plv the four most strongly implicated elements-fluoride,
selenium cobalt, and strontium-have relatively little toxic effect on either
It the 1 6vel s observed. The most dangerous would appear to be
urn wcoccrs at naturally high levels In the soils of the area.
of livestock can result from ingestion of many plants
85
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occurring in selenium-rich soils. The mechanism of this poisoning is not
completely understood but may be the result of selenium compounds within the
plants (Gough and Shacklette, 1976). The increase in selenium content of
grasses attributed to the powerplant does not appear to exceed 0.2 yg/1
(Conner et al., 1976) and is not detectable in the soils. It is doubtful that
selenium exerts any discernible effect in either increased toxicity or number
of toxic plants in the area.
Pesticides —
Data on pesticides in the San Juan Basin are limited. Samples have been
collected at the USGS stations in Vallecito Creek near Bayfield and in the San
Juan River at Shiprock, but more information is needed before an accurate
evaluation of conditions can be made. Additional pesticides may be
contributed to the river system as a result of proposed irrigation projects.
Radioactive Substances —
Radioactive elements-are not a problem in the surface waters at this time;
recent concentrations of radioactive substances are generally below the EPA
(1976a) Drinking Water Regulations for radionuclides (Table 29).
TABLE 29. U.S. ENVIRONMENTAL PROTECTION AGENCY DRINKING WATER REGULATIONS
FOR SELECTED RADIONUCLIDES
Radionuclide Allowable Level
(pCi/1)
Tritium (H3) 20,000
Strontium-90 8
Radium-226,228 (combined) 5
Gross alpha (excluding radon
and uranium) 15
Source: Modified from U.S. Environmental Protection Agency (1976a).
Tsivoglou et al. (1959) indicated that, in 1958-59, users of treated water
in Aztec and Fannington were ingesting 1.4 to 1.6 times the allowable daily
intake of radium-226 and strontium-90 as a result of liquid waste dscharoes
from the Durango mills. However, since mill closure n ?he early lllo'l
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radiation levels in the Animas River, the source of water for the two towns,
have not exceeded the permissible standards. Reports of more recent
terrestrial radioactive exposure have been recorded at the Shiprock tailing
piles, where the Navajo Engineering and Construction Authority was conducting
a Navajo training school for heavy equipment operators, and at Mexican Hat,
where the State of Utah was conducting a trade school in the old site
buildings (Douglas and Hans, 1975).
Suspended Sediments
Suspended sediment levels below Navajo Dam are low, whereas at Shiprock
the average concentration is 5,200 mg/1 and at Bluff average values reach
8,300 mg/1 (U.S. Bureau of Reclamation, 1976b). Canyon Largo, the Chaco
River, and Chinle Wash are responsible for much of this increase (lorns et
al., 1965). Thunderstorm activity in the basin plays a major role in the
observed seasonal fluctuations of suspended sediment (Table 30). Large
amounts of sediment are added to the river by intermittent streams during
periods of rainfall (U.S. Bureau of Reclamation, 1976b). Proposed energy
developments will reduce flow in the San Juan River, thus reducing the
sediment-carrying capacity of the river. Increased population accompanied by
a rise in construction and erosion as a result of these developments may also
affect sediment loading to the river (U.S. Bureau of Reclamation, 1976b).
Nutrients
Nutrient levels in the San Juan River below Archuleta and in the Animas
River at Farmington are periodically high enough to cause algal blooms
(Appendix B) although at present no major problem exists (U.S. Bureau of
Reclamation, 1975). Navajo Reservoir has been classified as mesoeutrophic by
the EPA (1977c). During the 1975 sampling, the median total phosphorus value
in the reservoir was 0.027 mg/1; the median inorganic nitrogen level was
0.120 mg/1, and the median dissolved orthophosphorus value was 0.010 mg/1. Of
the estimated annual total phosphorus loading of 166,610 kg/yr to the
reservoir, 72 percent was contributed by nonpoint loading from the Piedra,
San Juan, and Los Pinbs Rivers. If the current loading continues, eutrophic
conditions may result.
Agricultural runoff and sewage are major sources of nutrient loadings.
Planned irrigation projects could contribute additional nutrients to basin
waters. Nitrate leaching is not expected to be great, since much of the
chemical will be taken up by plant growth (U.S. Bureau of Reclamation, 1977b).
Phosphorus is absorbed by clay particles and reaches the river system mainly
via sediment erosion. Likelihood of such input is greatest at times of -
thunderstorm activity (U.S. Bureau of Indian Affairs, 1976). Increased sewage
and urban runoff, a result of the expected population expansion from proposed
irrigation projects and energy developments, could increase nutrient
concentrations in the river if not carefully controlled. Furthermore, coal
gasification may be used as a future source of hydrogen in the production of
ammonia. Fertilizer facilities in the area would increase the potential for
nitrogen contamination in the river.
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TABLE 30. MAXIMUM DAILY SUSPENDED SEDIMENT CONCENTRATIONS (mg 1) AT SELECTED U.S. GEOLOGICAL
SURVEY SAMPLING STATIONS IN THE SAN JUAN RIVER BASIN
00
oo
Month
October
November
December
January
February
March
April
May
June
July
August
September
San Juan River
near
Archuleta
1964-65 1968-69
5
7
120
65
30
100
100
560
200
110
37
76
An 1 mas
at
River
San Juan
River
at
Famrington
1964-65
110
280
344
1,100
440
2,600
8,400
1,700
660
11,000
20,000
7,100
1968-69
410
780
162
2,650
365
4,250
3,600
1,680
300
1.930
13,400
10,900
Shiprock
1964-68
1,300
11,000
6,400
32,000
5,600
4,300
6,800
2,000
6,400
22,000
39,300
6.600
1968-69
7,700
12,900
8,820
27,000
11,400
16,800
12,700
10,400
8,800
30,000
44,100
36,100
San Juan River
near
Bluff
1964-65
10,000
6,600
6,900
29,000
9,700
11,000
37,000
32,000
9,300
25.000
68,000
16,000
1968-69
12.900
12.800
1,140
18,600
13,400
8,320
12,800
28,600
22,200
67,200
45,500
54,700
-------
The New Mexico Water Quality Control Commission established a criterion of
u.l mg/i of total phosphorus in upstream reaches of the San Juan, La Plata,
and Animas Rivers (U.S. Bureau of Reclamation, 1976b). No criteria have yet
been set for waters below Farmington.
Temperature
Mean temperature values generally increase from upstream to downstream in
the San Juan River and its tributaries (Appendix B). Water temperature is
highest in July, August, and September and lowest during December, January,
and February (U.S. Bureau of Reclamation, 1975).
There will be no direct thermal discharge to the river from the two
powerplants and the propsed gasification plants. Return flows from the Navajo
Indian Irrigation Project are expected to have temperatures similar to that of
the river. However, these five projects will affect thermal conditions by
depleting water and thereby increasing the surface-to-volume ratio. The net
result will be more rapid heating of water during the day and faster cooling
at night (U.S. Bureau of Reclamation, 1976b).
Dissolved Oxygen
Waters in the San Juan River Basin are generally well aerated (Appendix
B). The dissolved oxygen minimum established by the EPA (1976c) for
maintaining healthy fish populations is 5.0 mg/1. Dissolved oxygen levels
from 1970 to 1976 at the USGS stations never dropped below this standard
except near Bluff; however, the 1.3 mg/1 minimum reported at this station in
1973 may be in error. Values below 5.0 mg/1 have been noted at the lower
depths of Navajo Reservoir (U.S. Environmental Protection Agency, 1977c), and
deoxygenation resulting in summer fish kills has occurred in the Chaco River
(Southwest Energy Study, 1972a).
The impact of the Navajo Indian Irrigation Project, the El Paso and WESCO
Coal Gasification Plants, and the Four Corners and San Juan Powerplants on
dissolved oxygen levels will probably be minimal except directly below Navajo
Dam where the water is supersaturated. Higher daytime water temperatures in
this areas as a result of the increased surface-to-volume ratio from reduced
flows could lower oxygen levels (U.S. Bureau of Reclamation, 1977c).
pH and Alkalinity
The ionic composition of water and, therefore, biological systems are
affected bv oH Waters in the San Juan River and the sampled tributaries are
basically alkaline with PH values usually between 7 and 9 (Appendix B). The
main except on is Mineral Creek where values ranged from 5.1 to 8.8 between
1970 and 1976 The EPA (1971) reported values from 4.6 to 7.1 in the creek
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during a 1965 and 1966 study, and a value of 4.0 was recorded in Cement Creek,
another headwater tributary of the Animas River. These low values are the
result of acid mine drainage. Sampling in Navajo Reservoir during 1975
yielded pH values from 7.45 to 8.65 (U.S. Environmental Protection Agency,
1977c).
The EPA (1976c) pH criterion for domestic water supplies is 5.0 to 9.0 and
for aquatic life, 6.5 to 9.0. As mentioned earlier, organisms have been
destroyed in the Animas headwater region, probably as a result of the low pH
values as well as the heavy metal concentrations. Other than this one problem
area, no values below 6.5 were detected at the USGS stations betwen 1970 and
1976. Acid mine drainage is not a problem in the Four Corners region because
of the low sulfur content of the coal and the small amount of precipitation,
which limits sulfuric acid formation. The buffering capacity of clay
particles in the area is also influential in preventing low pH values (U.S.
Bureau of Reclamation, 1976b). Occasional pH values over 9.0 were observed,
most often at the mainstem station near Archuleta.
Alkalinity plays a major role in moderating pH fluctuations. Alkalinity
values in the San Juan River and its tributaries tend to increase from
upstream to downstream (Appendix B). Alkalinity values in some of the
headwater streams are below 30, but in general waters in the San Juan Basin
are fairly well buffered. The lowest values in the basin were at Mineral
Creek as would be expected from its low pH levels.
Impact of San Juan River on Lake Powell
Lake Powell is the receiving water for the San Juan River, and any change
in the river system will have an effect on the lake and its outlet, the
Colorado River. Salinity, sediment, and nutrient loadings to the lake are the
major water quality concerns. Some trace element concentrations, particularly
mercury, are also approaching problem levels.
Turbid water enters the lake from the San Juan River but sediment settles
quickly in the delta area (U.S. Environmental Protection Agency, 1977b).
Reduction in flow from energy developments would decrease the river's
sediment-carrying capacity and thus reduce the sediment loading to Lake Powell
(U.S. Bureau of Reclamation, 1976b).
Lake Powell was sampled by EPA, EMSL-Las Vegas, in April, August, and
November 1975, June 1976, and April and May 1977. Specific conductivity
values observed at the mouth of the river were lower than those found further
down the San Juan in April and November 1975 and June 1976. During the August
1975 and April and May 1977 samplings, specific conductivity values were
slightly higher in the river. These observations are probably the result of
flow variations in the river. Flows at the mouth of the San Juan River in
August 1975 and in April and May 1977 were low, and as a result the dissolved
chemical concentrations (salinity) were high. If salinity levels in the river
rise, some increase in the conductivity of the San Juan Arm would occur.
Reynolds and Johnson (1974) discuss the advective circulation of Lake
Powell. They state that spring floodwaters are characteristically warm,
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fresh, and of relatively low density. These override the lake water and form
a mechanically induced thermocline and chemocline during the summer months.
Thermal convection is not enough to penetrate to the deepest waters of the
lake, and thus annual turnover never takes place. However, bottom waters in
this meromictic lake are not generally anaerobic. Anaerobic conditions in the
bottom waters are prevented by annual flushing of deep waters by dense, cold,
saline, oxygen-saturated water each winter. Although the Colorado and Green
Rivers provide the primary driving mechanism for the lake as a whole, the San
Juan River performs this flushing in the upper reaches of the San Ouan Arm.
Alteration of flow-salinity patterns by San Juan Basin water users could
conceivably alter this circulation pattern. If consumptive winter use reduces
the already low flows, winter flushing of the bottom waters in the lower San
Juan Arm may not occur. The main effect of anaerobic conditions would
probably be the solubilization of chemicals from sediments in affected areas;
phosphorus and mercury would be of prime concern.
The EPA (1976b) classified Lake Powell as being between oligotrophic and
mesotrophic during the 1975 sampling. In the middle and lower reaches of the
San Juan Arm, ammonia and Kjeldahl nitrogen levels, dissolved orthophosphorus
and total phosphorus values, and chlorophyll a_ levels were low. Nitrite-
nitrate values were moderate. Concentrations of dissolved orthophosphorus and
total phosphorus are relatively high where the river runs into the lake but
decrease down the arm (U.S. Environmental Protection Agency, 1977b). The lake
apparently acts as a nutrient sink with deposition occurring near the
tributary mouth (U.S. Environmental Protection Agency, 1976b). Lake Powell is
in the initial stages of the nutrient enrichment process (i.e.,
eutrophication); it is anticipated that increased nutrient input from the San
Juan River will accelerate the process.
IMPACT OF DEVELOPMENT ON GROUND WATER
Ambient Levels
Ground water in the shale and siltstone strata underlying most of the
basin is of fair to poor quality because of high concentrations of dissolved
solids (Price and Arnow, 1974). In the arid western portion of the basin,
water is found at depths of 305 m or greater. In the eastern region shallower
aquifers exist (U.S. Bureau of Reclamation, 1976a). The salinity problem
usually increases with depth as aquifers near the surface are recharged by
river water which generally contains lower concentrations of dissolved
solids. TDS concentrations of 1,000 mg/1 are common throughout the basin
(U.S. Bureau of Reclamation, 1976a).
Local ground-water quality variations result from differences in water
sources and soil permeability (U.S. Bureau of Reclamation, 1975). Thermal
springs near Pagosa Springs have a TDS concentration of 3,600 mg/1 with sodium
and sulfate ions predominating (lorns et al., 1965). In the Navajo Mine area
of the Chaco River, wells contain high levels of TDS consisting chiefly of
sodium, calcium, magnesium, and sulfate dissolved from the Kirtland and
Fruitland Formations. The Bureau of Reclamation (1976b) has reported that
water quality in these wells often exceeds the 1962 Public Health Service
Water Quality Standards. The Pictured Cliffs sandstone underlying the
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Fruitland Formation is the major source of ground water in this locality. The
average IDS value of 49 ground-water samples taken in this sandstone was
25,422 mg/1 (U.S. Bureau of Reclamation, 1975). Additional information on
water quality parameters in the Pictured Cliffs aquifer and shallow wells is
presented in Table 22. Water quality in this area was poor even before mining
operations were initiated (McWhorter et al., 1975). In the Menefee sands near
the proposed WESCO site, TDS concentrations around 1,400 mg/1 were measured
(U.S. Bureau of Reclamation, 1975). In the lower elevations of the McElmo
Creek Basin, the salinity of ground water ranges from 250 to 1,000 mg/1; other
areas in this vicinity have concentrations from 1,000 to 3,000 mg/1 (U.S.
Bureau of Reclamation, 1977b). Ground-water contributions of dissolved solids
at various other locations in the San Juan Basin are presented in Table 31.
In deep aquifers, no known problems result from radioactivity, pesticides,
or biological factors (U.S. Bureau of Reclamation, 1975). The trace element
concentration is low,probably because of the filtering effect of shale and the
high sulfate waters that decrease trace element solubility (U.S. Bureau of
Reclamation, 1976b).
Man's Impact
Water quality problems associated with mining include acidity, increased
salt content, higher heavy metal concentrations, and greater sediment loads
(Warner, 1974). Mines remain pollution sources even after closure, further
complicating pollution control.
The current and proposed mining developments in the San Juan Basin could
impact ground water in several ways. Interception of a ground-water flow is
one potential problem. Aquifers in the Navajo Mine area are deep, however,
making this possibility unlikely (Southwest Energy Study, 1972b). If ground
water is encountered as a result of mining activities, evaporation or
treatment of the impacted water, before discharge back to the aquifer, should
be undertaken to minimize contamination. A second problem involves disruption
of ground-water recharge areas. The proposed mine expansion is expected to
disturb approximately 1 percent of the recharge area 6f the shallow aquifers
nearby (U.S. Bureau of Reclamation, 1976a), which may result in an increase of
dissolved solids. A third possible problem is contamination of ground water
by infiltration from mining operations. If disruption of the protective shale
layer occurs, water could percolate through disturbed lands to the Pictured
Cliffs aquifer. This process is not anticipated to substantially impact water
resources since the quantity of water involved will probably be slight (U.S.
Bureau of Reclamation, 1976b). The small amount of salt pickup in subsurface
runoff from current mining operations has already been discussed in the
section. Precipitation infiltration may occur during the earlier stages of
reclamation. Seepage from storage or evaporation ponds may be expected.
Monitoring of well water quality in the immediate area and down geopotential
surfaces will be necessary to protect local users and detect possible
contamination.
Ground-water changes resulting from irrigation are caused by the
accumulation of TDS in the soil and subsequent seepage to shallow ground
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10
CO
TABLE 31. WATER AND DISSOLVED SOLIDS CONTRIBUTED BY GROUND WATER TO SELECTED STREAMS IN THE
Station
San Juan River near Pagosa Springs
San Juan River at Pagosa Springs
Navajo River at Edith
Piedra River near Piedra
San Juan River at Rosa
Animas River at Howardsville
Hermosa Creek near Hermosa
Animas River at Durango
La Plata River at Hesperus
Concentrations
of Total Dissolved
Solids (mg/1)
77
73
113
126
117
111-
219
183
84
Discharge
(m3x!06/yr)
18.996
60.194
36.263
59.208
204.760
21.216
25.163
210.926
7.524
Ground Water
Dissolved
(mg/1 }
100
138
183
254
221
173
411
300
115
Solids
(kgx!06/yr)
1.896
8.282
6.622
15.059
45.359
3.674
10.342
63.321
0.862
-------
water. In areas with deep aquifers, such as those underlying the Navajo
Indian Irrigation Project lands, the possibility of ground-water degradation is
lessened (U.S. Bureau of Indian Affairs, 1976).
Finally, utilization of ground water by energy developers can also impact
the surrounding area indirectly by lowering the water table. A high water
table provides a buffer against seasonal fluctuations of surface water. If
water in an alluvial aquifer is reduced, the near-surface water table
downstream is lowered, short-rooted vegetation is frequently desiccated, and
the reduced ground cover opens up unconsolidated material to increased erosion
(Atwood, 1975).
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9. ASSESSMENT OF ENERGY RESOURCE DEVELOPMENT
IMPACT ON WATER QUANTITY
In the San Juan Basin, surface water availability is the factor limiting
growth and development patterns, including development of energy resources.
It is estimated that New Mexico, the State where the greatest San Juan River
Basin development is occurring, is entitled to 896.7 million m3 per year
consumptive use of the Upper Colorado River. Of this amount, only
825.2 million m3 is actually available to users because of mainstem
evaporation. Effectively this entire amounc has been authorized for
development either in energy-related or irrigation projects (Table 12).
Water in the San Juan River Basin is naturally scarce, and flows are
erratic from season to season and from year to year. Dams and other control
structures tend to normalize, but can not eliminate, the effects of this
irregularity. Flow studies of years between 1915 and 1970 show that annual
water consumption by authorized users at today's rate is greater than the
annual flow of the San Juan River has been on five different occasions. In a
basin where less than 20 percent of the drainage area contributes more than 90
percent of the annual surface flow, and where high-quality ground water is
unavailable for resource mining, overutilization of existing flow cannot be
continued for an extended period of time. Energy development, particularly
surface mining and the subsequent conversion of coal into electricity,
requires enormous amounts of water. Large quantities of water are also needed
for reclamation projects to restore mined areas and for planned transportation
of coal out of the vicinity in a coal slurry line. This fact is significant
since most of the streams in the coal-rich area of the San Juan Basin are dry
much of the year, and only limited amounts of ground water are available to
supplement surface flows.
It is frequently assumed that all water not consumed is available for
diversion and energy utilization. This attitude overlooks the many ecological
needs for the "unused" water: in-stream flow maintenance for the preservation
of critical wetlands and riparian habitats, conservation of the native
environment of endangered species, etc. There are still a number of
high-quality trout streams flowing into the San Juan that can be irretrievably
damaged by lowered water levels or increased temperatures and sediment loads
from expanding irrigation and energy projects. Furthermore, the Bureau of
Indian Affairs (1976) has indicated that with all future authorized diversions
operational the San Juan River could become dry during a drought year for many
miles below Shiprock. This likelihood is further increased if the anticipated
return flow from the Navajo Indian Irrigation Project to the San Juan River is
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not realized. Many of the native fish of the San Juan, some of which are
already on threatened or endangered lists, occupy this stretch of the river.
Reductions in surface flow could also result in a lowering of the ground-water
table in some areas, causing desiccation of short-rooted vegetation, increased
erosion, and often destruction of terrestrial habitats where existing
vegetation satisfies wildlife and livestock consumptive needs. Water
requirements for waterfowl hunting areas in the San Juan Basin suggest
shortages will occur by 1980. Water shortages related to anticipated fishing
demands are expected to occur shortly thereafter.
The Upper Colorado Region State-Federal Inter-Agency Group (1971d) has
reported that "the maintenance of minimum flows for water quality purposes is
not recognized as a beneficial use in the water rights laws of any State in
the (Upper Colorado) Region." Historically the appropriation doctrine, the
basis for water law in most western States, required an actual diversion of
water prior to recognition of a water right. Recently, however, both
legislative actions and court rulings have recognized that minimum flows to
maintain fisheries are bonafide beneficial uses and that diversions are not
required (Gould, 1977; Cox and Walker, 1977). Colorado specifically amended
its water rights legislation to provide such recognition. In the State of
Colorado, 13 major river basins are being studied and in-stream flow
methodologies developed to provide a rationale for determining these in-stream
flow requirements (Johnson, 1978).
In the past (and presently) it was possible to completely divert a river
or stream leaving a dry bed. This has occurred in several locations in
headwater areas of the San Juan Basin as a result of agricultural diversions.
The Upper Colorado Region State-Federal Inter-Agency Group (1971c) recommends
that reservoirs should be maintained with minimum pools of sufficient depth
and size to support a permanent fishery in the impounded area and to allow for
continuous downstream releases of sufficient quantity to sustain stream
fisheries. Maintenance of a minimum flow also assures continuation of river
scouring of accumulating sediment, compensates for water loss from
transpiration, and helps prevent winter destruction of riffle areas resulting
from encroachment of ice. In-stream flow requirements may have a large impact
on the operation of reservoirs and other water storage and diversion
facilities, however. Shupe (1978) notes that storage reservoirs may be
operated at less than 50 percent efficiency and be largely dry for long
periods of time in order to meet in-stream flow requirements. The critical
reach of the San Juan River affected by energy resource development will be
the reach between Shiprock and Bluff. Further research is necessary to define
in-stream flow requirements for this and other stretches of the San Juan
River.
Officially, sufficient water has been allocated to support industry,
energy, urban development, and irrigation needs in the basin; however, it is
unrealistic to assume that a dependable water supply will continue to be
available under all conditions and seasons. The Colorado River Compact
authorizations and subsequent allocations were made based on a period that is
historically the wettest recorded. Average annual flows at Bluff have been
steadily declining; low water years have become more common and high flows
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have tended to be lower than in the past (Figure 7). The immediate method for
acquisition of water, which may ultimately be needed either by presently
authorized users or for future assigned allocations including in-stream flow
requirements, is the recommitment of water presently dedicated for other uses,
primarily agricultural. For continued energy resource production, development
of low water consumption energy technology will be necessary. However, in
anticipation of future water shortages, a number of additional possible means
to augment existing flows in the western States are being evaluated (U.S.
Department of Interior, 1974). Included among these are: weather
modification, sea water nuclear desalinization, mining of ground water from
closed basins, increased storage opportunities, and adjacent basin
ground-water pumping exchange programs. The Stanford Research Institute
(1976) has suggested that the option of transporting desalinated water to the
western energy basins from the Pacific Ocean, or using Mississippi River water
transported from up to 1,600 km away, is not financially prohibitive. Each of
the above proposals, however, pose their own economic, engineering, and
environmental problems, which must be dealt with before implementation can
take place.
IMPACT ON WATER QUALITY
Surface water quality in the San Juan Basin is generally good. Water
quality parameters are usually within the limits set by the U.S. EPA (1976c)
for domestic water supplies, irrigation, and aquatic life. Some problem areas
do exist, however. At present, salinity is the major concern. Energy
developments in the basin are expected to impact salt levels primarily through
salt-concentrating effects resulting from flow reductions. In addition, some
salt loading to near-surface ground waters will also occur. The Bureau of
Reclamation (1977c) estimates an average TDS increase of 228 mg/1 at Shiprock
in the year 2005 from the cumulative impact of the El Paso, WESCO, Four
Corners, and San Juan Plants and the Navajo Indian Irrigation Project. The
bulk of this predicted change is attributable to the latter development.
During low flow periods, the TDS increase may be even greater and could
severely impact beneficial water uses downstream. Adverse effects of higher
salinity include increased costs for municipal and industrial users, lower
crop yields, and deterioration of natural habitats. In addition, a
concentrating of the nonpoint pollutants entering the San Juan Arm and Lake
Powell can be expected as a result of flow reductions that lower the river's
capacity for dilution of salt and sediment loading.
Increases in sediment loading will be realized as a result of expanding
resource development in the area. All of the projects will intensify erosion
problems through construction activities, transport roads, and removal of
overburden for mining. Erosive action is already a problem in the basin; the
natural paucity of vegetation, combined with the arid climate and slow
weathering of rocks, produces organically poor soils highly susceptible to
sediment runoff during summer flash flooding. This increased sediment loading
will have a great impact on the downstream fish and benthic ecosystems of the
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river. It will result in sedimentation of riffle and other areas with
resultant adverse impact on aquatic ecosystems. Increased suspended sediment
levels can reduce primary productivity by decreasing the photic zone, as well
as necessitate extensive pretreatment of water prior to industrial or
municipal use. In areas where mainstem flows are stabilized or reduced,
sedimentation will occur, which may eventually force leveeing or dredging
activities to keep the river in its present channel and prevent loss of
developed properties. In some areas increased turbidity could result in
elevated stream temperature and loss of salmonid fisheries. As with salinity,
the problems of sediment loading to the San Juan River will be intensified by
reduced flows.
Some increase in nutrient and trace element concentrations can also be
expected as a result of flow reductions. Population expansion and
accompanying construction could further increase nutrient loading to the river
if not carefully controlled. The effect of the planned energy and irrigation
projects on temperature, dissolved oxygen, pH, and alkalinity are not expected
to be substantial and will, in all probability, be a result of the reduced
flow.
The quality of ground water in the basin is fair to poor as a result of
high concentrations of dissolved solids. Much of this low quality water is
natural to the basin, with dissolved solids and the major ions leaching into
the ground-water systems from the overlying shale. However, energy
developments can intensify the problem. In addition to reducing the
ground-water levels to supplement variable surface water flows, contamination
of the aquifers is possible. For example, both gasification complexes propose
to bury their waste materials, increasing the chance of heavy metals and salts
percolating into the ground-water system.
There are a number of mitigation measures that could be implemented to
reduce the potential impact of energy resource development on surface and
ground-water quality in the San Juan River Basin. These include: internal
recycling of wastewaters at coal conversion facilities, lining of discharge
reservoirs and evaporation ponds with impermeable materials to prevent
contamination of ground-water systems, active enforcement of zero discharge
from energy sites, and regular inspection of pipelines transporting either
wastewaters or liquid fuels such as oil or slurry coal. Regular monitoring
for potential violations from energy development operation sites is imperative
if pollution impact is to be kept to a minimum.
No known problems exist from contamination by radioactive decay,
pesticides, biological factors, or trace elements in the deep aquifers.
However, significant local contamination of ground water could occur and would
restrict the use of private wells.
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10. RECOMMENDED WATER QUALITY MONITORING PARAMETERS
An objective of water quality monitoring in the San Juan Basin should be
to assess the impact of energy resource development, irrigation projects, and
associated developments. Toward this end, a determination of those parameters
that would provide meaningful data is needed. The nature and type of possible
pollutants from the major activities in the Basin were inventoried. The
possible effects of these, as well as those parameters that are already being
monitored, were reviewed and a proposed priority list of parameters of
interest in the San Juan Basin was prepared.
PHYSICAL AND CHEMICAL PARAMETERS
The selection of which water quality parameters should be routinely
monitored in the San Juan Basin is not obvious. Physical data provide
information on temperature, amount (flow), osmotic pressures (salinity,
conductivity), and other factors that affect both the biota and the chemistry.
The utility of these data must then be considered when selecting which
parameters to measure. Similarly, the ambient level of a chemical present and
its effect upon the biota and interactions with other chemicals present must
be known if a cost-effective monitoring network is to be implemented.
In addition to assessing the quality throughout the water column, the
monitoring of substrate composition is also necessary. Many organic and
inorganic pollutants are adsorbed onto sediment particles or organic debris.
Other pollutants, such as iron, may form flocculants or precipitates, or may
sink of their own accord. These materials may be deposited in areas of slower
moving water or left as evaporites in the dry washes of the area. They may,
however, be resuspended during periods of erosion or be released as dissolved
parameters following a change in environmental conditions. The deposited
sediments, therefore, represent both a pollutant sink and a potential source.
It is necessary to monitor bottom-sediment composition in order to obtain a
full picture of environmental pollution.
As a means of identifying and giving priority to those parameters most
appropriate for monitoring energy development, each potential pollutant
previously addressed is evaluated in terms of the projected impact on ambient
water quality with respect to beneficial water use criteria. Also evaluated
are those "indicator parameters" that, although not in themselves pollutants,
either provide a direct or indirect measurement of environmental disturbances
or are required for the interpretation of water quality data. The following
symbols are used for identifying those beneficial water uses affected by
existing or projected increases in parameter ambient levels:
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Symbol Beneficial Water Uses
I = Irrigation
D = Drinking water (public water supplies)
A = Aquatic life and wildlife
W = Industrial uses
L = Livestock drinking
Three priority classifications were developed based on criteria given
below. These are:
Priority I (Must Monitor Parameters) ~ should be collected
regularly at energy development assessment monitoring stations (Table 32);
Priority II (Major Interest Parameters) — would be desirable
to monitor in addition to Priority I parameters if resources permit
(Table 33); and
Priority III (Minor Interest Parameters) -- are presently being
monitored by the existing network but which will provide little useful
data for monitoring energy development impacts on water quality in the San
Juan Basin (Table 34).
This classification represents an attempt to (a) identify those parameters
that will be effective in monitoring the impact of energy development in the
San Juan Basin, or (b) permit the detection of increases in parameter levels
that may be deleterious to designated beneficial water uses.* This
classification scheme is not intended to preclude monitoring of low priority
or unmentioned parameters for special studies or for purposes other than
assessment of energy development impact. Neither does it require the
elimination of very-inexpensive-to-monitor parameters already being collected
for baseline data. The priorities do not attempt to address sampling
frequency. However, monitoring frequency is discussed briefly in Section 11
and will be addressed in greater detail in subsequent documents in this energy
series.
Parameters for use in the rapid detection of short duration events such as
spills, monitoring for permit discharge purposes, and intensive survey or
research projects are not considered in this report. These concerns are
important and should not be neglected, but they require considerations that
are beyond the scope of this report.
*A11 assessments relative to beneficial water uses are based on U.S. EPA
(1976b) criteria or drinking water regulations (U.S. Environmental Protection
Agency, 1975). In those cases where no EPA criteria exist, National Academy
of Sciences (1973) recommended criteria are used.
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TABLE 32. PRIORITY I, MUST MONITOR PARAMETERS FOR THE ASSESSMENT OF ENERGY DEVELOPMENT
IMPACT ON WATER QUALITY IN THE SAN JUAN RIVER BASIN
Parameter t
Primary Reason for Monitoring
Category Code tt
Alkalinity, total (as CaCOj)
Ammonia, total as N
Arsenic, totalt
Bicarbonate ion
Biological oxygen demand of sediments,
5 day
Boron, total
Cadmium, total
Carbon, total organic in sediments
Calcium, dissolved
Chloride
Chromium, totalt
Specific conductance, at 2SeC
Copper, total
Cyanide, totalt
Dissolved oxygen
Flow
Iron, totalt
Needed for interpretation of water quality data 4
Periodically exceeded recommended levels for aquatic life, expected to increase 2A; 3A
Periodically exceeded EPA criteria for drinking water in the Animas River, may 2D; 3D
increase near gasification sites
Major anion in the upper Basin, may be affected by energy development 4
Measure of pollution increases in the Basin, sediment serves as an integrative 4
accumulator
Exceeded livestock consumption and irrigation criteria in lower Basin 21,L
Commonly exceeded criteria for drinking water and aquatic life, levels may be 2A,D; 3A.D
increased at gasification sites
Provides Indication of organic contamination, many elements and compounds are 4
preferentially adsorbed onto organic debris
Major cation in Basin, may be affected by energy development 4
Increased levels anticipated from mine spoil drainage 3D,I
Levels reported in excess of both drinking water, irrigation, and aquatic life 2A,0,I
criteria in lower Basin
Useful Indicator of TDS, affects overall water chemistry 4
Exceeded Irrigation water criteria in lower Basin 21
Reported levels have exceeded criteria for aquatic life, can be expected to 2A; 3A
increase (a by-product of gasification)
Necessary for maintainance of aquatic life and affects water chemistry 1; 4
Needed for interpretation of water quality data 1
Levels have exceeded EPA criteria for aquatic life, drinking water, and irrigation 2A,0,I
In the Basin
(Continued)
tUnmarked parameters are determined in water samples only; marked parameters include both
water samples and bottom sediments, unless specified for bottom sediments only.
ttFor full explanation of category codes, see Section 10.
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TABLE 32. (Continued)
Parameter!
Primary Reason for Monitoring
Category Codett
o
ro
Lead, totalt
Magnesiun, dissolved
Manganese, totalt
Mercury, totalt
Molybdenum, total
Pesticides
Petroleum hydrocarbons (includes
benzene, toluene, oil and grease,
napthalene, phenols, olefins,
thiophenes, and cresols)
Exceeded drinking water and aquatic life standards at several lower basin sites, 2A,D; 3A,D
may Be increased by gasification plants
Important cation in Basin, may be affected by energy development 4
Periodically exceeded criteria for drinking water and Irrigation, may be increased 2D,I; 3D,I
by gasification
Periodically exceeded EPA criterion for aquatic life, possible contribution from 2A; 3A; 4
powerplants and gasification plants
Exceeded irrigation water criteria in McElmo Creek area HI
From available data, only dieldrin and DDT were reported at levels exceeding 2A; 3A.D
criteria for aquatic life. However, with increasing agricultural activity, levels
of other pesticide/herbicides may be expected to increase
Can be expected to increase throughout the Basin 3A,D
pH
Phosphorus, totalt
Potassium, dissolved
Selenium, totalt
Sodium, dissolved
Sulfate, dissolved
Suspended sediments
Temperature
Total dissolved solids
Vanadium, dissolved
Needed for interpretation of water quality data
Primary nutrient contributing to algae and macrophyte growth, expected to increase
Important cation in Basin, may be affected by energy development
Reported levels exceeded drinking water criteria in some lower basin areas, and
reached irrigation criterion levels at McElmo Creek; levels may increase as a
result of stack emissions
Important cation in basin, increased levels anticipated from mine spoil drainage
and increased use of water conditioners
Dominant anion in lower basin, may be affected by energy development
Major transport mechanism, indicator parameter
Needed for interpretation of water quality data, could increase with development
Indicator parameter, downstream salinity problem anticipated with increasing
irrigation and energy development
Values routinely exceed established criteria for livestock and irrigation uses by
an order or magnitude
1; 4
4
4
20,1; 3D, I
3D, I; 4
4
1; 4
1; 3A; 4
2D.I; 3D, I,
W; 4
21, L
tunmarked parameters are determined in water samples only; marked parameters include both
water samples and bottom sediments.
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TABLE 33. PRIORITY II, PARAMETERS OF MAJOR INTEREST FOR THE ASSESSMENT OF ENERGY
DEVELOPMENT IMPACT ON WATER QUALITY IN THE SAN JUAN RIVER BASIN
Parameter!
Primary Reason for Monitoring
Category Codett
BOD, 5 day
COO, low level
Fluorlde
Total hardness, CaCo3
Kjeldahl - N, total
Nitrate-nitrite - N
Sediment size distribution
Turbidity
May provide basic information on increased pollution 7
May provide an indication of pollution by oxygen-consuming substances 7
Not presently a problem, could increase in the lower river to levels that can 6D.I.L
cause teeth mottling
Of interest to both industry and public, not a problem at present but may become 6D,I,U; 7
so as water consumption and irrigation runoff Increase
Primary nutrient, expected to increase with development 7
Primary nutrient, expected to increase, could approach health limits in the future 6D; 7
Provides data on stream velocity, stream habitat, sediment sources 7
Easy to measure, provide quick data about suspended sediment, etc. 7
tParameters determined in water samples only.
ttFor full explanation of category codes, see Section 10.
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TABLE 34. PRIORITY III, PARAMETERS OF MINOR INTEREST THAT WILL PROVIDE LITTLE USEFUL DATA
FOR THE ASSESSMENT OF ENERGY DEVELOPMENT IMPACT ON WATER QUALITY IN THE SAN JUAN
RIVER BASIN
Parametert
Primary Reason for Monitoring
Category Codett
Aluminum, total
Barium, dissolved
Beryl Hum, dissolved
Bismuth, dissolved
Carbonate
Chromium (hexavalent)
Cobalt, total
Gallium, dissolved
Germanium, dissolved
Lithium, total
Nickel, dissolved
Nitrate - Nt
Nitrite - NJ
Nitrogen, total
Phosphorus, dissolved ortho
Rubidium, dissolved
Sediment minerology
Silica
Silver, total
Strontium, dissolved
Tin, dissolved
Titanium, dissolved
Zinc, total
Zirconium, dissolved
At Farmington. levels reportedly exceeded irrigation and livestock criteria; 8
however, values are generally an order of magnitude below established criteria
Difficult to neasure, does not approach critical limits 8
Recorded values are low g
Recorded values are very low a
Low levels in basin, usually of little significance In alkaline waters 8
Recorded values are zero or very low g
Levels generally low in basin, has few adverse effects at high levels 8
Values very low (maximum 7 pg/1) g
Values very low (maximum 8 uQ/1) g
Reported values very low (maximum 11 ug/1) g
Levels generally low (maximum 50 ug/1). could be Increased near gasification sites 8
Monitored simultaneously by N02-N03. If NOj-NOa-N levels begin to approach 8
10.000 wg/1 then the N02 form would become a "must nonltor" priority for health
reasons
Provides little practical information g
Total P has been found to more strongly Influence biological activity 8
Only one reported value (0.5 ug/1), very low g
Hay provide sediment maximum source data g
Generally low throughout the basin g
Levels generally very low (in ug/l) 8
Levels very high In lower basin, but has little biological effect 8
Very low levels (maximum 29 ug/1). little adverse effects R
Reported values very low (maximum 12 Mg/l) although nay be high in sediments 8
Maximum level reported 1900 ug/1 at Faraington (below criteria) 8
Reported values very low (maximum 12 ug/1) g
tParameters determined In water samples only.
ttFor full explanation of category codes, see Section 10.
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The reasons for monitoring each parameter listed on Tables 32-34 are
categorized by the following classification scheme.
Priority I - Must Monitor Parameters
1. Parameters essential for the interpretation of other water
quality data. This consideration includes parameters, such as
temperature, pH, and flow, that are necessary to determine
loadings, chemical equilibria, biological response, or other
factors affecting other parameters.
2. Parameters commonly exceeding water quality criteria.
Consideration is of EPA water quality criteria for beneficial
water uses (see codes presented earlier). In cases where
present EPA criteria do not exist, criteria recommended by the
National Academy of Sciences (1973) are used.
3. Parameters expected to increase to levels exceeding water
quality criteria, unless extreme care is taken. This category
includes organic chemical compounds that are expected to be
present in future discharges from energy developments, and that
could reach lethal, mutagem'c, or carcinogenic levels unless
extreme care is taken. The beneficial use symbols for water
quality criteria expected to be exceeded are used here.
4. Parameters that are useful "trace" or "indicator" parameters.
These include parameters that, although not causing substantial
impact to the aquatic environment themselves, are used to define
pollution sources, estimate other parameters of concern, or
provide general data on the overall quality of the water. An
example wou-ld be conductivity, which reflects highly saline
springs.
5. Parameters expected to be altered by energy development
activities so as to present a threat to a rare or endangered
species. These include parameters that do not normally affect
aquatic life at encountered values but that, under unique
circumstances, may affect a threatened or endangered species.
Priority II - Ma.ior Interest Parameters
6. Potential pollutants of concern. Parameters whose reported
levels in the San Juan Basin are presently within acceptable
limits for beneficial water uses, but whose ambient levels could
be altered by planned regional developments to levels that
impair those uses. This differs from category 3 in that, while
category 3 parameters are expected to produce problems
(either environmental or abatement/disposal), category 6 are
those that might be a problem if unrestricted development were
permitted.
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7. Marginal "trace" or "indicator" parameters. These include
parameters that may be used to provide general data on
overall quality of the water, locate pollutant source
areas, or estimate other parameters. Such parameters are
not presently routinely monitored or provide little advantage
over other measurements being made.
Priority III - Minor Interest Parameters
8. Parameters that are present at very low levels and are unlikely
to be significantly changed by planned regional development,
are fairly easily monitored but have little effect on
beneficial water uses at encountered levels, or provide little
useful data for monitoring energy or other development. Many
of these parameters are currently being monitored on a regular
basis in the San Juan River Basin; however, for purposes of
monitoring energy impact development, these parameters are not
necessary.
Priorities are arranged alphabetically within Tables 32-34. The order of
their appearance is not intended to suggest a ranking of relative importance.
Although frequency of measurement is not addressed by the priority
listings, whenever possible at least monthly collection is recommended for
most water quality parameters. Standard analytical techniques should be
utilized and the data should be processed and entered into data bases as soon
as possible after collection. It should also be stressed that changing
conditions within the study area may cause some changes in the priority
listings, especially addition of currently unmonitored compounds for which
little data are available.
Analysis of bottom sediment samples on an annual or semiannual basis
should be performed. Total organic carbon, BOD, grain size, and elemental
data should be determined. Sediments from Navajo Reservoir and Lake Powell
should also be sampled and analyzed on a regular basis. Because extensive
organic extractions and analysis from sediment samples are expensive, it is
not recommended that analysis for specific toxic organic compounds be
performed on a routine basis. These analyses should be performed as special
studies rather than on a routine monitoring basis at the present time.
Bottom-sediment parameters of interest are included on Tables 32-34; priority
ranking of parameters for sediment samples followed the same considerations
used in establishing priorities for the water column.
BIOLOGICAL PARAMETERS
The collection of biological data in the San Juan River Basin would be an
effective complementary tool for assessing the impact of energy or irrigation
development. Biological investigations are of special significance in water
quality monitoring programs because they offer a means of identifying areas
affected by pollution and of assessing the degree of stress from relatively
small changes in physical-chemical parameters. Aquatic organisms act as
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natural monitors of water quality because the composition and structure of
plant and animal communities are the result of the biological, chemical, and
physical interactions within the system. When only periodic physical-chemical
data are collected, an episodic event such as a flash flood or spill may go
undetected. The biota affected by an occasional event may require weeks or
months to recover. In addition, many biological forms that accumulate various
chemicals preferentially serve as both an integrative and concentration
mechanism that may permit detection of pollutants not detected in the water
itself. Finally, because the biota are affected by all materials and
conditions present in the system, they could be the first indication of a
major hazard posed by some unsuspected, unmonitored compound.
Biological monitoring should be initiated in a regular fashion within the
San Juan River system. It should not be viewed as an alternative to other
monitoring but as a complementary tool for improving the efficacy of
monitoring programs. A comprehensive monitoring program is recommended to
gather baseline data and permit the eventual refinement of techniques. Such a
monitoring effort should be designed to obtain standardized, reproducible data
that may be compared from station to station and across time. Sampling
methods and sites will obviously differ for the different biological
communities or parameters. However, for a given community and parameter,
sites should be selected that have similar characteristics and the same
sampling device and technique used for collection efforts. Replicate samples
should be routinely collected and analyzed separately for quality assurance
reasons. Of primary interest in biological monitoring is the assessment of
changes in community structure over time and space; for such comparisons a
minimum of a single year of baseline data is necessary and the accumulation of
several years data is generally required to demonstrate natural temporal
variations in the Basin's communities.
Taxonomic groups considered appropriate for biological monitoring in the
San Juan River Basin are discussed below.
Macroi nvertebrates
These larger forms are relatively easy to collect, quantify, and identify
to a meaningful taxonomic level. Being relatively stationary, they are unable
to escape oncoming waste materials, and their life cycles are sufficiently
long to prevent an apparent recovery to periodic relief from pollution.
Seasonal sampling (based on stream temperature and flows) should be conducted
although annual or semiannual records could be beneficial. Care must be taken
to allow sufficient time between sampling of identical areas to permit
disturbed populations to reestablish themselves. Macroinvertebrate sampling
in lakes should be investigated to determine if sufficient macrobenthos exist
to make monitoring them worthwhile.
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Periphyton
The periphyton, like the macrobenthos, are unable to escape pollution
events. Widespread, rapidly growing, and easy to sample, they are the primary
producers in flowing systems and provide basic data on the overall quality of
streams and lakes.
Fish
These represent the top of the aquatic food chain and respond to
the cumulative effects of stresses on lower forms. In addition, they
represent an element of intense public concern. Unlike the previous
communities, fish have considerable mobility and may be able to escape
localized pollution events. Fish are readily sampled, and taxonomic
identification is not difficult in most cases.
Zooplankton
Zooplankton include organisms that graze upon phytoplankton and in turn
provide a major food supply for higher forms. The Zooplankton can be
responsible for unusually low phytoplankton levels as a result of their
grazing activities. These forms may provide basic information on
environmental regimes and, because of their relatively short life spans and
fecundity, may be the first indication of subacute pollution hazards.
Phytoplankton
Present in nearly all natural waters, these plants are easily sampled
and can provide basic data on productivity, water quality, potential
or occurring problems, etc. Phytoplankton sampling is recommended in
lakes and ponds but is not recommended for stream monitoring in this basin.
Microorganisms
Coliform bacteria are generally considered to be indicative of
fecal contamination and are one of the most frequently applied indicators
of water quality. Criteria exist for bathing and shellfish harvesting
waters (U.S. Environmental Protection Agency, 1976c). Other microbiological
forms may be useful in the San Juan Basin, but these have not been identified
and are not discussed.
An annotated list of parameters (Tables 35-36) is recommended for
monitoring the impact of energy resource development in the San Juan River
Basin. The Priority I category includes those parameters that generally
demonstrate an observable response to the type of stress conditions
anticipated as a result of increased energy development activities and for
which effective monitoring techniques have been developed. It is recommended
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TABLE 35. PRIORITY I BIOLOGICAL PARAMETERS RECOMMENDED FOR MONITORING WATER QUALITY
IN THE SAN JUAN RIVER BASIN
Taxonomlc Group Parameters
Expressed As
Reason for Sampling
Macroinvertebrates Counts and identification
Total number/taxon/unit sampling
area or unit effort
Provides data on species present,
community composition, etc., which
may be related to water quality
or other environmental considerations
Biomass
Weight/unit sampling area or unit effort Provides data on productivity
Periphyton
Biomass
Weight/unit substrate
Provides data on productivity
O
VO
Growth rate
Identification and
estimation of relative
abundances*
Weight/unit substrate/time
Taxon present
Provides data on productivity
Indicative of community composition
that may be related to water quality
rate of recovery from a biological
catastrophe, etc.
Fish
Identification and
enumeration
Species present*
Provides data on water quality, environmental
conditions, and, possibly, water uses.
Different species respond to different stresses
(Continued)
*Gross estimates of the quality or percent of each taxon should be made rather than
specific count data/unit area.
**Count data should be provided for each species.
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TABLE 35. (Continued)
Taxononric Group
Parameters
Expressed As
Reason for Sampling
Fish
Toxic substance in tissue Weight substance/unit tissue weight
(by species)
Indication of biological response to toxic
pollutants, may provide an "early warning"
of pollutants not detected in the water, may
pose a health hazard in itself
Zooplankton
Identification and
count
Species present
Provides basic data upon environmental
conditions
Total unit volume or biomass
Number/species/unit volume
Provides data upon community composition,
environmental conditions, and available food
size ranges
Macrophytes
Species identification
and community association
Areal coverage and community
Indication of stream stability, sedimentation,
and other factors; spread of phreatophytes
could be a problem in the basin because of their
effect on water quality; initial survey and thereafter
occasional examination of aquatic and stream (lake)
Side plants is recommended
(Continued)
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TABLE 35. (Continued)
Taxonomic Group
Parameters
Expressed As
Reason for Sampling
Phytoplankton
Chiorophyl1 a
xg/1
Indication of overall lake productivity;
excessive levels often indicate enrichment
problems
Identification and
enumeration
Number/taxon/unit volume
Total number/sample (unit volume)
of biomass
The presence of specific taxon in abundance
is often indicative of water quality and may
In itself pose a biological problem
Microorganisms
Total fecal coliform
Number/unit volume
Indicative of fecal contamination of water
supplies and probable presence of other
pathogenic organisms
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TABLE 36. PRIORITY II BIOLOGICAL PARAMETERS RECOMMENDED FOR MONITORING WATER QUALITY
IN THE SAN JUAN RIVER BASIN
Taxonomic Group
Parameters
Expressed As
Reason for Sampling
Macrolnvertebrates Toxic Substances in tissue Weight substance/jjnit tissue weight
Indicative of biological response to
toxic pollutants, may provide an "early
warning" of pollutants not detected in
the water itself
Periphyton
Chlorophyll a
Unit substrate area
Indicative of productivity of area and
general health of the periphyton community
ro
Taxonomic counts
Number/taxon/unit substrate area
Provides additional data on periphyton
community composition
Fish
Biomass
Total weight/sampling effort
or unit volume
Indicative of secondary productivity of the
water body
Flesh tainting
Rating scale (by species)
Indicative of high levels of organic compounds;
likely to be noticed by public; could indicate
pollution from several sources to be due to other
causes
(Continued)
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TABLE 36. (Continued)
Taxonomic Group Parameters
Expressed As
Reason for Sampling
Fish
Size
Length, weight/Individual, or range
and average size species
Provides an indication of the age of the
community, breeding potential, and secondary
productivity rates
Condition factor
Weight/length (by species)
Indicative of general health of fish community
and availability of food
Growth rate
Age/length (by species)
Provide data on overall health of the fish
community and environmental conditions; could
indicate the presence of subacute pollutants
Zooplankton
Blomass
Weight/unit volume
Basic data on abundance and overall productivity
Eggs, instars, etc.
Species present
Provides basic data on age distribution,
presence of seasonal forms, or the existence
of cyclic pollution events
Toxic substances in tissue Weight/unit tissue (by species)
May serve as bioconcentrator for specific compounds
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that Priority I parameters be incorporated into any aquatic biological
monitoring program in the basin. The Priority II parameters are those that
may be of value to the Basin but that are not generally considered to be as
likely to provide useful data as those in the Priority I category and should
only be collected in addition to Priority I parameters if time and money are
available.
It should be noted that the count and biomass determinations in the
following discussion are not productivity measurements. Rather they are
expressions of standing crops and, although indicative of general
productivity, are really quite different. Productivity data are expressed in
units of mass/volume (or area)/unit time.
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11. ASSESSMENT OF EXISTING MONITORING NETWORK
Estimations can be made regarding the possible impact of proposed
developments on water quality, but only after operation can the actual impact
be assessed. A well-developed sampling network for the monitoring of
environmental parameters is helpful, not only in controlling and assessing
pollution from existing projects, but also in providing valuable information
for evaluating future projects.
Thirty-five sampling stations in the San Juan River Basin were analyzed to
evaluate trends in surface water quality; 22 of these are U.S. Geological
Survey sites (Table 17), and 13 are operated by the Colorado State Health
Department (Table 18). This combination network of State and Federal agency
stations appears to be generally well situated for monitoring of surface water
impacted by energy and irrigation projects located in the San Juan River.
Until recently, there have been no surface water stations located along
the Chaco River, which will receive both surface and ground-water discharge
from Navajo Mine, the Four Corners Plant, the WESCO and El Paso Gasification
Projects, and the Navajo Indian Irrigation Project. Potential runoff from
uranium mining in the southwestern portions of the watershed could also
eventually impact the San Juan River through Chaco Wash. Part of the
difficulty in monitoring this important flow is that the Chaco River is an
ephemeral stream, making monitoring more difficult than in a perennial river.
Nevertheless, the USGS has recently installed a stream gaging station in the
mouth of the river near Waterflow, New Mexico, and plans are underway to put
an automatic pump sampler at this station, at Chaco Canyon National Monument,
and on Hunter Wash in the Burnham area (Ong and Dewey, 1975). Additional
gaging and water quality sites have also been established along Shumway Arroyo
(near the San Juan Mine) by the USGS in cooperation with the Bureau of Land
Management. The addition of a gaging station in the San Juan River between
Shiprock and Bluff is also recommended in light of the predicted impact to
flow in that stretch of river after all authorized water users are active.
Good baseline data are available from the Shiprock station, and this
location, in particular, should be considered for weekly sampling of
top-priority water quality parameters. Its proximity to the mouth of the
Chaco River makes it the most likely locality for observation of water quality
degradation in the San Juan River from the Navajo Mine, the Four Corners
Plant, and the WESCO and El Paso Gasification Projects. If funding permits,
weekly sampling in the San Juan River at Farmington would also be desirable.
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It should be noted that there is no known ground-water monitoring network
in the San Juan Basin; it is felt that at the present time there is no need
for establishment of one. Surveys of wells, as specified in Section 3, "Rural
Water Survey", PL 93-523, the "Safe Drinking Water Act," are recommended
should local contamination from energy or other developments occur.
Physical and chemical parameters monitored by the sampling network in the
San Juan Basin and their average annual frequency of measurement are shown in
Table 37. This table was constructed from data inventories present in STORET.
The average number of times a parameter was sampled each year over the period
of record is indicated for each station. Although the completed sampling
network in the Basin should be adequately located for monitoring the impact of
energy development and other activities, it is apparent that there are a
number of data collection problems with the sampling net that reduce the
interpretive utility of the accumulated data. In the past, there has been
little uniformity of sampling frequency for many of the parameters. Stations
have not been,sampled at consistent intervals nor data collected on similar
dates, making spatial or temporal comparisons of data difficult. Monitoring
of the same parameters, or even the same forms (e...g_., dissolved versus total
iron), is not consistent from station to station. Many of the parameters
recorded in Table 32 as Priority I for monitoring of energy development
impact, particularly the trace elements and nutrients, are sampled only
intermittently or infrequently. The elemental analyses performed by the USGS
are usually for dissolved forms, while the Colorado State Health Department
monitors for total forms. A few other Priority I parameters, such as phenols,
oils, greases, and pesticides, are completely lacking from the existing
network or are sampled only rarely. Very little biological data has been
gathered by the existing monitoring network in the Basin. Inconsistencies
such as these greatly complicate analysis of long- and short-term trends,
comparisons of data between stations, and selection of suitable parameters for
valid statistical analyses.
If necessary, the number of stations regularly sampled in the Basin could
be substantially reduced. Those USGS stations indicated on Table 38 are
recommended as having the highest sampling priority irj the San Juan River
Basin for monitoring the impact of energy development there. Of these six
priority stations (Table 38), sites 19 and 21 at Farmington and Shiprock,
respectively, are the best located for the maintenance of any continuous
monitoring activities for energy impact assessment. It is recommended that
these two stations be sampled on a weekly basis to provide a valid statistical
data base to evaluate trends over a three- to five-year time period. All key
stations should be sampled on a monthly basis at a minimum to establish
baseline distribution data. Presently the Farmington, Shiprock, and Bluff
stations are the most frequently sampled in the USGS network (Table 37),
particularly for collection of basic monitoring parameters, such as
temperature and flow, and for salts. However, almost all the elemental
parameters considered as having a high monitoring priority (Table 32) are
largely neglected, and very little data are available for them at any location
throughout the basin.
116
-------
TABLE 37. PARAMETERS MONITORED BY THE EXISTING SAMPLING NETWORK IN*THE SAN JUAN
RIVER BASIN AND THEIR AVERAGE FREQUENCY OF MEASUREMENT
Parameter!
00010 WATER
00011 WATER
00060 STREAM
00070 TURB
00095 CNDUCTVY
00300 DO
00310 BOO
00335 COD
00400 PH
00410 T ALK
00440 HC03 ION
00445 C03 ION
00530 RESIDUE
00600 TOTAL N
00610 NH3-N
00615 N02-N
00620 N03-N
00625 TOT KJEL
00630 N026M03
00665 PHOS-TOT
00671 PHOS-DIS
00900 TOT HARD
00902 NC HARD
00915 CALCIUM
00980 CALCIUM
00925 MGNSIUM
00927 MGNSIUM
00930 SODIUM
00929 SODIUM
00931 SODIUM
USGS Station Numbers
OOGGOOOGCGOOOO'OOOC'OO-GO
C OOOOtftOOOOOOOOOOOOOOG-c
cvioro^c*i^ero^j>(MOO^miD<*jo\u>i/>4nOi/>ci/i
i-«rornco*fr^-i£>ior>.o-iC\j*rinr-vCOr*-oo«*i«iocGoi>
^-•!r*r*9-*»^-'«*«3-''4-^-in4/au>tni«in*o\o»c«3*er^
f^focafOrocorocoro<^icococofrifO CO
to co 10 O to o
O O O i-H O ,-H
§00000
o o o o o
o o o o o o
7
6*
7
4
7
5
5
5
6
5
5
5
5
5
5
4*
5
3
5
4
4
4
4
4
4
4
4
4
(C
8
6*
8
3
7
5
5
5
6
5
5
5
5
5
ont
5
5
5
4
4
4
4
4
5
4
4
4
4
Inu
4
3
4
3
4
5
5
5
5
6
5
5
5
5
ed)
6
5*
5
4
5
5
5
5
5
5
5
5
5
5
Numbers
«* CO C-J
tO to l£>
8 88
o o o
o o o
6
5
5
3
6
4
4
4
5
5
5
5
5
5
7 8
6* 5*
7 8
5 4
3 4
fi 5
4r
b
S 5
5 5
5 5
5 5
5 5
5 5
5 5
5 5
V J
5 5
tParameters are listed by STORET code, name, form, and unit.
indicates Hach turbidity unit; I intermittently sampled.
-------
TABLE 37. (Continued)
USGS Station Numbers
Colorado Station Nunfoers
I
00
Parameter!
iiiililllllilllillllll
<=oooooS>ggSgSgSgSgggggg
c^joc <^r-.-t\o^rinro*3-ooc«j
00935
00940
00945
00950
00951
00955
01000
01001
01002
01005
01010
01015
01020
01022
01025
01027
01030
01032
01034
01037
01040
01042
01045
01046
01049
01051
01054
01055
01056 '
01060
01062
01065
01075
01077
PTSSIUM
CHLORIDE
SULFATE
FLUORIDE
FLUORIDE
SILICA
ARSENIC
ARSENIC
ARSENIC
BARIUM
BERYL IUM
BISMUTH
BORON
BORON
CADMIUM
CADMIUM
CHROMIUM
CHROMIUM
CHROMIUM
COBALT
COPPER
COPPER
IRON
IRON
LEAD
LEAD
MANGNESE
MANGNESE
MANGHESE
HOLY
HOLY
NICKEL
SILVER
SILVER
K.DISS
CL
S04-TOT
F.DISS
TOTAL
DISSOLVED
AS.DISS
AS, SUSP
AS, TOT
BA.DISS
BE.DISS
BI.DISS
B.DISS
B.TOT
CD.DISS
CD, TOT
CR.DISS
HEX-VAL
CR.TOT
CO, TOTAL
CU.OISS
CU.TOT
FE.TOT
FE.DISS
PB.DISS
PB.TOT
MN.SUSP
MN
MN.DISS
HO.DISS
TOTAL
NI.DISS
AG.DISS
TOTAL
MG/L
MGA
MG/L
MGA
MG/L
MG/L
UGA
UGA
UGA
UG/L
UG/L
UG/L
UG/L
UG/L
UG/L
UG/L
UG/L
UG/L
UGA
UG/L
UG/L
UG/L
UG/L
UG/L
UGA
UG/L
UG/L
UGA
UG/L
UGA
10 8
10 8
10 8
10 8
10 8
I
I
10 8
I
I
I
10 8
I
10 I
I
6
6
6
6
6
2
2
6
2
2
2
6
2
2
2
6
6
6
6
6
1
I
6
I
I
I
6
I
I
I
8
8
6
8
8
I
I
8
I
I
I
8
I
I
I
6
6
6
6
6
I
I
6
I
I
I
6
I
I
I
6
6
6
6
6
2
I
6
2
I
I
2
6
2
I
2
2
2
I
6 10
6 10
6 10
6 10
6 10
6
I
I
I
4 9
2
1
2
4 9
1
9
2
I
1
I
6 12
6 12
6 12
6 12
6 12
4 1
4
I 4
I
I
4 4
1 1
4
1 I
I
1
1 1
4
4
4 12
1 i
5
4
2 18
I i
1 I
I I
8
8
ft
8
8
4
I
I
I
4
1
1
1
4
1
1
(
1
I
6
6
6
6
6
3
2
2
4
j
I
6
2
4
2
1
2
2
2
4
2
2
6
1
3
2
2
3
I
I
4
12 9 12
12 9 12
12 9 12
12 9 12
12 9 12
I
I I
I
1
826
I i
I
I
I
I
I
I
I
I
2 12 9
I
j i
I 9
12
I
1
I
7
5
2
7
4
3
5
6
4
g
12 24
12 52
12 52
12 24
12 52
2 2
j i
i t
I 4
3 I
i
i
12 12
I i
i i
2 3
I I
I j
3 2
I I
I i
i i
2 3
I I
I I
12 12
I i
4 4
^ ^
T T
1 1
I I
2 1
I
2
4 24
4 52
4 52
52
52
y
&
24
2
36
y
£.
4
y
C-
4
2
4
4
12
•>
L.
I
2
r
L
T
I
24
52 4 4
52 4 4
24
52
644
24
n A
4 4
(j
644
g
6 4
\J *t
664
c.
o
6
644
644
2
644
2
3 4
y y
66545455
66545455
44444445
66645454
4 114
44444445
66646455
66645454
33343434
TT199990
5
4
3
5
4
3
4
3
5
3
5
3
•>
5 5
5 5
4 4
4 4
4 5
5 5
5 4
4 4
5 5
4 4
5 5
2 3
O 1
(Continued)
-------
TABLE 37. (Continued)
USGS Station Numbers
Colorado Station Numbers
OOOOO
Lr>OCGO
Parameter t
01080
01085
01092
01100
01105
01120
01125
01132
01135
01145
01146
01150
01160
01300
31501
31505
31616
31615
70299
70300
70301
70302
71890
72895
71900
80154
80155
STRONTIUM
VANADIUM
ZINC
TIN
AlUMINUM
GALLIUM
GERMANUM
LITHIUM
RUBIDIUM
SELENIUM
SELENIUM
TITANIUM
ZIRCONUM
OIL-GRSE
TOT COLI
TOT COLI
FEC COLI
FEC COLI
RES-SUSP
RESIDUE
DISS SOL
DISS SOL
MERCURY
MERCURY
MERCURY
SUSP SED
SUSP SED
SR.DISS
V.DISS
ZN.TOT
SN.DISS
AL.TOT
GA.DISS
GE.D1SS
LI, TOT
RB.DISS
SE.DISS
•SE.SUSP
cr Tfvr
JL , IUI
TI.OISS
ZR.DISS
HFIMENDO
MPNCONF
MFM-FCBR
MPNECMED
AT 180 C
DISS-180
SUM
HG.DISS
HG.SUSP
HG, TOTAL
CONC
DISCHARGE
UG/L
UG/L
UG/L
UG/L
UG/L
UGA
UGA
UG/L
UG/L
UG/L
UG/L
UG/L
UG/L
SEVERITY
/100ML
/100ML
/100ML
/100ML
MG/L
UG/L
MG/L
TONS DAY
UG/L
UG/L
UG/L
MGA
TONS DAY
ro ro PO ro ro ro oo ro ro ro n ro ro co ro ro ro ro PO -*co ro ro
roooooooooooooocoooooo
2
2 I I I I
211 12
4
I 2 I I I 4
6
2866866
10 8 6 6 8 6 6
10 8 6 6 8 6 6
12 III
4 24 3 12 12
4 24 3 12 12
I
1
I
I
I
I
I
4
6
6
I
6
6
6
6
6
I I I I I
1111 I
421 16
I II I
II II
I II I
I II I
I I I
I I
141 346
2 146
40T| * ft f.
ell 1 H n
i i i i i
i i i i i
I 4 2 4 12 12 2 2 24 12
6 12 6 24 6 6 24 12
6 12 8 12 6 6 24 12 12
I I 2 12 6
10 6 4 6 6 1 2 2 52 1 36 52
10 6 12 6 12 12 12 12 52 4 52 24
10 6 9 -6 12 12 12 12 52 4 52 52
12 166
21 166
2 4 I I 466
4 12 6 12 12 12 12 26
4 12 6 12 12 12 12 26
.-*i-iOOOOGi-iOi-tOOO
coooooooooooo
OOOGOQOOOQOOC
CC-OGOOOOOOOOO
4466645454555
5477746465566
5477746465566
4
4477746 65666
444 12 642144342
-------
TABLE 38. U.S. GEOLOGICAL SURVEY STATIONS RECOMMENDED TO HAVE HIGHEST
SAMPLING PRIORITY IN THE SAN JUAN RIVER BASIN FOR MONITORING
ENERGY DEVELOPMENT
Station Number* Station Name
13 San Juan River at Archuleta, NM
17 Am'mas River near Cedar Hill, NM
19 San Juan River at Farmington, NM (below Am'mas River)
21 San Juan River at Shiprock, NM
22 San Juan River near Bluff, UT
unassigned Chaco Wash at mouth
*Station numbers arbitrarily assigned for purposes of this report; see
Table 17.
120
-------
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Matter of Pollution of the Interstate Waters of the Colorado River and its
Tributaries - Colorado, New Mexico, Arizona, California, Nevada, Wyoming,
Utah. Volume 2,-Seventh Session, Las Vegas, Nevada. 151 pp.
U.S. Department of the Interior. 1974. Report on Water for Energy in the
Upper Colorado River Basin. Water for Energy Management Team. 62 pp.
U.S. Environmental Protection Agency. 1971. The Mineral Quality Problem in
the Colorado River Basin. Proceedings of the Conference in the Matter of
Pollution of the Interstate Waters of the Colorado River and its
Tributaries - Colorado, New Mexico, Arizona, California, Nevada, Wyoming,
Utah. Volume 1, Seventh Session, Las Vegas, Nevada. 10 pp.
U.S. Environmental Protection Agency. 1973. Biological Field and Laboratory
Methods. #EPA-670/4-73-001. Cincinnati, Ohio. 176 pp.
U.S. Environmental Protection Agency. 1975. Water Programs: National
Interim Primary Drinking Water Regulations. Federal Regsister
40(248):59566-59574.
U.S. Environmental Protection Agency. 1976a. National Interim Primary
Drinking Water Regulations. #EPA-570/9-76-003. Office of Water Supply,
Washington, D.C. 159 pp.
U.S. Environmental Protection Agency. 1976b. Proceedings of National
Conference on Health, Environmental Effects, and Control Technology of
Energy Use. #600/7-76-002. Washington, D.C. 340 pp.
U.S. Environmental Protection Agency. 1976c. Quality Criteria for Water.
tfEPA-440/9-76-023. Washington, D.C. 501 pp.
U.S. Environmental Protection Agency. 1977a. Oil Spills and Spills of
Hazardous Substances. Oil and Special Materials Control Division, Office
of Water Program Operations, Washington, D.C. 41 pp.
126
-------
U.S. Environmental Protection Agency. 1977b. Report on Lake Powell. Working
Paper#733. Draft report. 33 pp.
U.S. Environmental Protection Agency. 1977c. Report on Navajo Reservoir.
Working Paper #775. Draft report. 16 pp.
U.S. Geological Survey. 1970. Quality of Surface Waters of the United
States, 1965. Colorado River Basin to Pacific State Basin in California.
U.S. Geological Survey Water Supply Paper 1965. -Washington, D.C. Parts
9-11. 678 pp.
U.S. Geological Survey. 1974. Quality of Surface Waters of the United
States, 1969. Colorado River Basin and the Great Basin. U.S. Geological
Survey Water Supply Paper #2148. Washington, D.C. Parts 9-10. 348 pp.
U.S. Public Health Service. 1962. Public Health Service Drinking Water
Standards. Report #956. U.S. Department of Health, Education and
Welfare. Washington, D.C. 61 pp.
U.S. Soil Conservation Service, U.S. Economic Research Service, and U.S.
Forest Service. 1974. Water and Related Land Resources, San Juan River
Basin, Arizona, Colorado, New Mexico, and Utah. Denver, Colorado.
207 pp.
Utah State University. 1975. Colorado River Regional Assessment Study. Part
II: Detailed Analyses: Narrative Description, Data, Methodology, and
Documentation. Contract #WQ5AC054. Logan, Utah. 479 pp.
Warner, D.L. 1974. Rationale and Methodology for Monitoring Groundwater
Polluted by Mining Activities. #EPA-680/4-74-003, U.S. Environmental
Protection Agency, Las Vegas, Nevada. 76 pp.
Westinghouse Environmental Services Division. 1975. Four Corners Power
Generating Plant and Navajo Coal Mine. Environmental Report. 984 pp.
127
-------
APPENDIX A
CONVERSION FACTORS
In this report, metric units are frequently abbreviated using the
notations shown below. The metric units can be converted to English units by
multiplying the factors given in the following list:
Metric unit
to convert
Centimeters (cm)
Cubic meters (m3)
Cubic meters sec/(cms)
Hectares (ha)
Joules/gram (g)
Kilograms (kg)
Kilograms (kg)
Kilometers (km)
Liters (1)
Liters (1)
Meters (m)
Square kilometers (km2)
Square kilometers (km2)
Multiply by
0.3937
8.107 x ID'4
35.315
2.471
0.430
2.205
1.102 x 10-3
0.6214
6.294 x 103
0.2642
3.281
247.1
0.3861
English unit
to obtain
Inches
Acre-feet
Cubic feet/sec
Acres
BTU/pound
Pounds
Tons (short)
Miles
Barrels (crude oil)
Gallons
Feet
Acres
Square miles
128
-------
APPENDIX B
CHEMICAL AND PHYSICAL DATA
Number Page
B-l Flow, 1970-1976, at U.S. Geological Survey Sampling Stations
in the San Juan River Basin 131
B-2 Dissolved Solids, Sum of Constituents, 1970-1977, at U.S.
Geological Survey Sampling Stations in the San Juan River
Basin 132
B-3 Conductivity, 1970-1977, at U.S. Geological Survey Sampling
Stations in the San Juan River Basin 133
B-4 Dissolved Calcium, 1970-1977, at U.S. Geological Survey
Sampling Stations in the San Juan River Basin 134
B-5 Dissolved Sodium, 1970-1977, at U.S. Geological Survey
Sampling Stations in the San Juan River Basin 135
B-6 Dissolved Magnesium, 1970-1977, at U.S. Geological Survey
Sampling Stations in the San Juan River Basin 136
B-7 Dissolved Potassium, 1970-1977, at U.S. Geological Survey
Sampling Stations in the San Juan River Basin 137
B-8 Bicarbonate Ion, 1970-1977, at U.S. Geological Survey Sampling
Stations in the San Juan River Basin 138
B-9 Sulfate, 1970-1977, at U.S. Geological Survey Sampling
Stations in the San Juan River Basin 139
B-10 Chloride, 1970-1977, at U.S. Geological Survey Sampling
Stations in the San Juan River Basin 140
B-ll Dissolved Silica, 1970-1977, at U.S. Geological Survey
Sampling Stations in the San Juan River Basin 141
B-12 Total Hardness, 1970-1977, at U.S. Geological Survey Sampling
Stations in the San Juan River Basin 142
B-13 Total Iron, 1970-1976, at Colorado State Health Department
Sampling Stations in the San Juan River Basin . . . . . . . . 143
B-14 Total Manganese, 1970-1976, at Colorado State Health Department
Sampling Stations in the San Juan River Basin ........ 144
B-15 Concentrations of Trace Elements at Selected Colorado State
Health Department Sampling Stations, 1968-1976 •••••••• 145
B-16 Ambient Levels of Total Phosphorus and Dissolved Orthophosphorus,
1973-1976, at Selected U.S. Geological Survey Sampling
Stations in the San Juan River Basin . ... ......... 146
B-17 Ambient Levels of Nitrate-Nitrite, Total Kjeldahl, and Ammonia,
1973-1976, at Selected U.S. Geological Survey Sampling
Stations in the San Juan River Basin . ............ 147
B-18 Temperature, 1970-1977, at U.S. Geological Survey Sampling
Stations in the San Juan River Basin 148
B-19 Dissolved Oxygen, 1970-1977, at U.S..Geological Survey Sampling
Stations in the San Juan River Basin 149
129
-------
Number Page
B-20 pH, 1970-1977, at U.S. Geological Survey Sampling Stations in
the San Juan River Basin 150
B-21 Total Alkalinity, 1970-1977, at U.S. Geological Survey Sampling
Stations in the San Juan River Basin 151
130
-------
TABLE B-l. FLOW (m3/sec), 1970-1976, AT U.S. GEOLOGICAL SURVEY SAMPLING STATIONS
IN THE SAN JUAN RIVER BASIN
Station
timber*
01
02
03
04
05
06
07
08
09
10
11
12
13
14
15
16
17
18
19
20
21
22
1970
x (mln-nax) n
0.4(0.3-0.4)2
—
—
—
—
—
4.7(1.1-15.6)5
7.6(3.8-42.8)8
0.5(0.3-0.7)2
9.3(1.9-28.3)8
1.9(0.9-2.6)10
4.4(1.7-9.8)8
30.9(12.3-57.2)12
31.2(8.0-59.7)10
0.3(0.2-0.3)2
1.5(1.2-1.7)2
24.4(7.2-63.1)12
39.5(6.8-222.3)13
56.4(13.3-231.9)60
0.6(0.1-2.6)8
57.2(8.8-320.0)59
153.3(12.4-1495.3)31
1971
x (nln-Mx) n
1.2(0.2-2.8)8
—
—
—
—
—
1.2(1.0-1.4)4
9.0(4.7-18.4)4
1.2(0.3-3.6)9
6.3(2.8-13.4)4
4.7(0.3-14.7)20
3.6(1.5-5.3)4
26.1(8.8-77.2)12
21.0(3.2-75.6)12
1.0(0.3-3.2)10
4.8(1.2-17.4)9
22.4(6.9-90.4)12
24.0(2.2-72.5)22
39.5(11.0-83.8)50
0.6(0.2-1.0)4
44.7(9.0-170.5)69
59.6(12.9-181.8)26
1972
X (Bin-Max) n
1.2(0.1-2.8)9
—
—
0.7(0.3-1.7)9
—
—
47.9(0.6-2.5)9
10.4(2.5-27:8)4
1.8(0.2-4.6)9
8.2(1.2-17.6)4
4.2(0.4-13.6)18
3.6(3.2-3.9)4
22.1(11.5-42.8)11
26.2(7.9-51.8)11
1.0(0.2-2.9)9
5.4(1.0-20.2)9
19.7(7.8-46.2)11
17.3(2.0-45.6)11
42.9(9.9-286.0)62
0.6(<0.01-3.1)14
41.7(3.6-265.6)50
105.7(2.6-756.2)27
1973
x (Bin-Max) n
2.3(0.1-9.8)9
6.4(4.3-8.5)2
4.2(2.8-5.7)2
2.3(0.03-0.1)6
—
8.4(2.6-11.3)3
—
—
3.3(0.4-11.2)9
—
7.3(0.4-32.0)19
—
—
57.0(13.0-116.1)9
1.2(0.08-3.4)9
6.2(0.4-13.4)9
54.7(32.8-76.5)2
11.2(7.5-22.7)5
122.5(20.4-300.2)28
3.5(0.4-10.9)8
126.3(37.1-317.2)33
124.3(45.3-331.3)21
1974 1975 1976
x (nln-Bax) n x (aln-Bax) n x (Bin-Max) n
0.9(0.5-7.6)9 * — —
— — _
_
_ _
—
_
1.2(-)1
_
0.9(0.2-1.8)9 — —
—
2.9(0.3-10.9)13
—
36.9(26.6-56.7)5 — —
37.5(25.2-56.6)5 —
0.7(0.1-1.6)9
3.4(0.5-8.9)9
—
—
36.5(15.9-70.2)41 89.3(23.8-241.0)28 34.9(21.5-45.3)6
—
34.3(6.1-81.8)28 89.1(20.2-291.7)36 35.9(14.2-85.2)19
51.5(24.1-110.4)15 26.7(28.3-213.0)12 53.1(14.2-30.4)8
*For full description of station locations, see Table 17.
fx represents the mean for all samples, the range is given in parentheses, and n indicates
the total number of samples collected.
-------
TABLE B-2. DISSOLVED SOLIDS, SUM OF CONSTITUENTS (mg/1), 1970-1977, AT U.S. GEOLOGICAL
SURVEY SAMPLING STATIONS IN THE SAN JUAN RIVER BASIN
CO
ro
Station
Number*
01
02
03
04
05
06
07
Ofl
09
10
11
12
13
14
15
16
17
18
19
20
21
22
1970
x (•ln-max) n
44(41-48)2
—
—
—
—
—
132(95-161)5
173(90-287)8
58(53-62)2
187(96-275)8
46(35-52)4
136(87-164)8
151(135-170)12
280(178- 383J11
194(183-204)2
170(160-181)2
275(154-462)9
340(161-494)12
321(162-1720)63
641(317-965)2
413(174-1290)60
507(306-999)19
1971
x (mln-max) n
41(35-47)9
—
—
—
—
—
162(14 3-170)4
182(108-230)4
53(41-61)9
198(134-260)4
'.4(25-58)16
154(130-174)4
I65(I40-1S3)I2
367(180-633)12
118(63-152)9
125(63-169)9
297(189-374)5
371(148-580)12
333(168-609)48
767(439-1090)3
492(226-1230)53
583010-938)12
1972
x (Bln-nax) n
43(33-50)9
—
~
~
—
—
155(119-177)3
200(86-267)4
53(38-62)9
225(93-297)4
46(34-74)16
166(129-201)4
183(173-193)11
335(223-425)11
126(51-209)9
127(59-193)9
310(148-384)6
384(222-591)11
381(224-1100)50
732(575-946)4
570(227-2020)50
624(399-1120)16
1973
x (mln-nuix) n
39(34-59)9
103(-)1
100(96-105)2
135(122-148)2
117(-)l
118(118-118)2
192(167-241)5
198(191-206)2
56(39-66)9
185(145-225)2
46(24-65)15
120(110-131)2
180(145-214)10
259(202-415)11
157(57-320)9
145(69-226)9
244(209-278)2
361(154-543)11
244(155-423)36
582(363-801)2
302(170-518)45
428(195-775)12
1974
x (nln-nax) n
42(30-47)9
90(54-119)7
91(55-124)7
110(66-138)6
100(65-126)7
100(60-128)7
162(114-195)9
~
52(27-63)9
—
45(26-59)16
1«2(-)1
167(151-179)12
322(199-598)12
112(55-304)9
144(73-225)9
—
483(210-682)12
371(190-1480)36
—
447(248-1060)39
599(324-791)11
1975
x (nln-aax) n
42(30-61)9
—
—
—
, —
—
—
—
50(34-64)9
—
41(23-54)13
—
176(127-206)13
287(200-533)12
170(48-370)9
136(71-226)9
—
383(114-557)13
280(154-673)42
—
360(169-732)48
615(179-2650)13
1976 1977
x (nin-nax) n x (nln-nax) n
—
—
—
—
—
—
—
—
—
43(20-62)11 49(31-81)9
—
158(144-171)12 162(156-171)10
362(219-1270)12 325(221-390)9
—
—
—
428(142-620)12 536(328-798)9
330(165-819)23 401(251-1190)26
—
455(180-993)45 608(335-1200)29
561(321-814)11 747(448-1170)11
*For full description of station locations, see Table 17.
tx represents the mean for all samples, the range is given in parentheses, and n indicates
the total number of samples collected.
-------
TABLE B-3. CONDUCTIVITY (pmho/cm at 25° C), 1970-1977, AT U.S. GEOLOGICAL SURVEY
SAMPLING STATIONS IN THE SAN JUAN RIVER BASIN
GO
to
Station
Number*
01
02
03
04
05
06
07
08
09
10
"
12
13
14
15
16
17
18
19
20
21
22
1970
x (min-max) n
59(57-61)2
—
—
~
—
—
193(128-242)5
265(130-460)8
72(70-75)2
297(140-470)8
75(60-90)5
231(150-315)8
245(219-270)12
442(290-593)11
297(283-311)2
275(264-286)2
454(238-710)12
520(273-765)13
498(279-2290)65
1086(501-1440)8
645(307-1890)60
655(250-1310)25
1971
x (min-max) n
47(38-55)9
—
—
—
—
—
230(215-245)4
267(160-353)4
65(43-109)9
305(200-406)4
72(41-100)18
253(193-300)4
260(210-285)12
549(272-952)13
170(90-237)9
180(90-270)9
458(165-650)12
577(239-920)12
528(265-930)53
1154(600-1510)4
731(350-1700)54
813(280-1280)15
1972
x (min-max) n
48(34-60)9
161(142-219)12
168(142-257)20
159(142-177)9
—
—
244(173-299)4
302(125-430)4
57(40-80)9
344(142-461)4
67(55-101)17
282(225-323)4
285(262-300)11
515(345-665)11
193(82-300)9
196(96-298)9
419(253-620)11
607(364-912)11
586(360-1580)62
1039(656-1400)14
843(343-2660)50
870(550-1510)18
1973
x (mln-max) n
49(40-76)9
114(80-146)6
110(87-142)7
159(105-238)5
130(74-222)6
151(98-172)7
235(107-387)9
314(302-327)2
70(41-100)9
298(237-358)2
80(33-115)15
200(188-210)2
285(227-340)11
408(326-660)11
232(80-478)9
218(116-354)9
409(219-577)8
564(255-831)11
409(263-675)46
840(354-1200)10
466(284-788)45
657(320-1170)12
1974
x (mln-max) n
44(30-64)9
124(69-175)13
124(71-184)15
174(92-250)13
142(78-193)16
164(80-380)16
242(112-324)18
—
59(44-75)9
—
71(42-90)16
309 (-)l
272(236-295)12
517(333-940)12
245(91-461)9
232(123-354)9
—
748(354-1030)12
589(325-2050)38
—
698(408-1550)40
922(521-1200)13
1975
x (min-max) n
52(34-80)9
—
102(69-131)21
—
—
198(124-231)6
—
—
60(43-80)8
—
66(41-86)14
—
292(230-320)13
452(320-814)12
238(60-529)9
216(105-358)9
—
602(205-878)13
448(255-1050)42
—
559(280-1030)48
808(300-3200)14
1976 1977
x (mln-max) n x (min-max) n
—
—
—
—
—
—
—
—
—
—
82(50-120)11 81(49-110)9
—
284(240-330)12 229(199-480)10
556(350-1800)12 494(360-600)9
—
—
—
687(260-895)12 819(495-1125)9
488(307-1000)23 616(400-1630)24
—
702(315-1390)43 1096(540-6379)30
796(500-1074)11 1031(660-1610)11
*For full description of station locations, see Table 17.
fx represents the mean for all samples, the range is given in parentheses, and n indicates
the total number of samples collected.
-------
TABLE B-4. DISSOLVED CALCIUM (mg/1), 1970-1977, AT U.S. GEOLOGICAL SURVEY SAMPLING
STATIONS IN THE SAN JUAN RIVER BASIN
<*)
Station
Number*
01
O2
03
• 04
05
06
07
08
09
10
11
12
13
14
15
16
17
18
19
20
21
22
1970
x (min-roax) n
6(5-6)2
—
~
—
—
—
24(17-28)5
28(15-44)8
7(7-7)2
41(22-58)8
11(9-11)4
29(20-34)8
29(25-32)12
47(32-6S)ll
44(41-44)2
43(41-45)2
62(38-76)9
72(38-105)11
56(34-192)64
100(54-145)2
71(36-202)60
82(56-162)21
1971
x (niln-max) n
5(4-7)9
—
—
—
—
—
26(24-28)4
27(16-32)4
6(4-8)9
41(30-52)4
10(5-15)16
32(27-34)4
31(26-34)12
55(31-69)12
26(13-35)9
31(15-42)9
63(46-77)5
77(32-110)12
60(27-130)40
116(67-160)3
73(42-200)53
76(0-130)13
1972
x (mln-toax) n
6(5-7)9
—
—
—
—
—
28(19-34)4
32(14-38)4
6(5-8)9
47(19-59)4
10(6-13)17
34(28-32)4
33(31-37)11
54(38-66)11
28(12-46)9
32(14-49)9
64(34-78)6
79(47-120)11
65(40-130)50
109(77-150)4
83(33-240)50
88(60-150)16
1973
x (rain-mar) n
7(4-9)8
17(-)1
17(16-18)2
23(23-23)2
19(-)1
19(19-19)2
33(29-41)5
32(32-33)2
7(4-9)9
40(33-47)2
10(5-14)15
27(26-29)2
29(27-36)11
43(38-58)11
37(20-78)'>
36(17-58)9
52(47-58)2
75(36-110)11
45(32-71)35
90(60-120)2
51(34-78)44
64(36-94)12
1974
x (mln-mnx) n
5(4-7)9
16(8-22)7
16(8-23)7
19(11-24)6
16(9-21)7
16(9-21)7
28(19-35)9
—
6(5-8)9
—
10(5-13)16
35(-)l
32(28-34)12
51(36-84)12
38(14-76)9
38(19-60)9
—
99(48-130)12
62(35-160)36
—
70(48-140)40
84(51-110)11
1975
x (mln-nax) n
6(4-8)9
—
—
—
—
—
--
—
6(4-9)9
—
11(6-24)14
—
32(25-38)13
46(36-63)12
41(11-93)9
35(17-60)9
—
80(26-150)13
50(33-79)42
—
59(24-91)48
82(34-260)13
1976 1977
x (min-max) n x (mln-max) n
__
—
—
_
—
—
—
—
—
—
10(4-15)11 11(7-16)9
—
30(28-32)12 30(29-31)10
51(37-120)12 51(37-60)9
—
—
--
90(34-120)12 107(68-150)9
53(34-110)24 62(43-140)2(.
—
70(31-120)45 85(53-150)29
83(55-120)11 101(70-140)11
*For full description of station locations, see Table 17.
fx represents the mean for all samples, the range is given in parentheses, and n indicates
the total number of samples collected.
-------
TABLE B-5. DISSOLVED SODIUM (mg/1), 1970-1977, AT U.S. GEOLOGICAL SURVEY SAMPLING
STATIONS IN THE SAN JUAN RIVER BASIN
OJ
en
Station
Number*
01
02
03
04
05
06
07
08
09
10
11
12
13
1*
15
16
17
18
19
20
21
22
1970
x (mln-max) n
3(3-3)2
—
—
—
—
—
8(6-10)5
17(7-30)8
4(4-5)2
13(4-20)8
1(1-2)4
13(6-18)8
13(11-18)12
36(19-55)11
3(3-3)2
2(2-2)2
16(5-34)9
22(7-32)13
38(11-332)64
36(15-56)2
36(4-66)18
58(24-142)21
1971
x (nin-max) n
3(2-4)9
—
—
—
—
—
10(10-10)4
18(11-26)4
4(2-5)9
13(7-19)4
1(1-2)16
16(13-20)4
14(12-16)12
52(21-120)12
3(1-6)9
2(1-3)9
19(8-28)5
29(8-53)12
37(10-100)48
42(22-64)3
64(24-250)53
72(32-140)12
1972
x (Bin-Max) n
3(2-5)9
—
—
—
—
—
10(6-12)4
20(6-30)4
3(2-5)9
15(5-22)4
1(0-5)17
18(13-21)4
16(14-17)11
42(23-59)11
3(1-6)9
2(1-3)9
22(6-35)6
26(14-52)11
43(19-200)50
40(26-53)4
75(24-310)50
80(36-170)16
1973
X (win-wax) n
3(2-5)9
8(-H
8(8-8)2
10(9-10)2
6(-)l
7(6-7)2
12(10-16)5
16(15-18)2
4(2-5)9
10(6-15)2
X
1(0-3)15
9(6-11)2
14(11-25)11
32(18-78)11
3(1-6)9
3(1-4)9
13(8-19)2
27(6-48)11
24(11-62)36
29(16-42)2
30(11-77)44
50(17-110)12
1974
x (nin-nax) n
3(2-4)9
6(4-8)7
7(4-9)7
8(5-11)6
6(3-8)7
6(3-8)7
10(6-12)9
4(2-6)9
4(3-5)9
—
1(0-3)16
24(-)l
15(13-16)12
43(21-96)12
3(1-5)9
1(2-3)9
—
40(12-64)12
46(16-300)36
—
58(23-190)40
75(32-110)11
1975 1976 1977
x (•In-nax) n x (ain-iiax) n x (nln-nax) n
3(2-6)9
— — —
—
— —
—
—
_
—
4(2-6)9
—
1(0-2)14 1(1-2)11 2(1-4)9
—
16(11-20)13 14(12-15)12 14(14-16)10
37(22-111)12 54(24-270)12 41(23-55)9
3(1-6)9
2(1-3)9
_
29(5-46)13 35(6-73)12 44(24-75)9
31(11-140)42 37(12-140)24 58(25-240)26
—
44(12-140)48 57(15-180)45 85(40-240)29
77(14-140)13 64(29-92)11 97(48-170)11
*For full description of station locations, see Table 17.
fx represents the mean for all samples, the range is given in parentheses, and n indicates
the total number of samples collected.
-------
TABLE B-6. DISSOLVED MAGNESIUM (mg/1), 1970-1977, AT U.S. GEOLOGICAL SURVEY SAMPLING
STATIONS IN THE SAN JUAN RIVER BASIN
CO
Station
Number*
01
02
03
04
05
06
07
08
09
10
"
12
13
14
15
16
17
18
19
20
21
22
1970
x (raln-raax) n
1(1-1)2
—
—
—
—
—
5(4-7)5
6(3-13)8
2(1-2)2
6(3-8)8
2(2-2)4
5(3-6)8
5(4-5)12
6(5-8)11
3(3-3)2
2(2-3)2
10(5-22)9
10(4-17)13
8(4-23)64
50(25-76)2
11(5-23)60
20(10-32)21
1971
x (min-max) n
1(0-1)9
—
—
—
—
—
7(6-7)4
7(4-9)4
1(1-1)9
6(4-7)4
2(1-3)16
5(4-6)4
5(5-6)12
8(6-10)12
2(1-2)9
2(1-3)9
10(6-12)5
13(4-18)12
8(4-17)48
61(36-82)3
14(5-23)53
24(12-36)12
1972
x (mln-max) n
1(0-1)9
—
—
—
—
—
7(5-9)4
8(3-10)4
1(1-1)9
7(3-9)4
2(1-3)17
6(4-7)4
6(5-6)11
8(6-10)11
2(1-3)9
2(1-3)9
11(5-14)16
12(7-18)11
10(6-15)50
55(41-72)4
16(7-49)50
21(11-37)16
1973
x (mln-max) n
1(0-1)9
2(-)l
2(2-2)2
6(4-9)2
3(-)l
4(3-5)2
9(7-13)5
10(9-11)2
1(1-2)9
6(6-7)2
2(1-4)15
4(4-4)2
6(5-8)11
7(7-10)11
2(1-4)9
2(1-3)9
9(9-10)2
12(5-18)11
8(4-13)36
45(27-63)2
10(6-17)44
17(8-31)12 •
1974
x (min-max) n
1(0-1)9
2(1-4)7
2(1-4)7
4(2-6)6
2(1-3)7
3(2-4)7
7(6-9)9
—
1(1-2)9
—
2(1-2)16
6(-)l
6(6-7)12
8(6-9)12
2(1-4)9
2(1-3)9
—
14(6-21)12
9(6-21)36
—
13(8-23)40
26(15-36)11
1975 1976
x (mln-max) n x (mln-max) n
1(0-1)9
—
—
—
—
—
—
—
1(0-1)9
_
2(1-3)14 2(1-4)11
—
7(5-8)13 6(5-6)12
8(6-9)12 8(6-12)12
2(1-5)9
2(1-4)9
—
13(4-17)13 13(4-18)12
8(5-12)42 8(6-10)24
—
11(6-19)48 14(6-36)45
30(8-160)13 22(13-37)11
1977
x (min-max) n
—
—
—
—
—
—
—
—
—
—
3(2-4)9
—
6(5-6)10
8(7-9)9
—
—
—
16(10-23)9
9(7-17)26
—
18(9-46)29
28(16-43)11
*For full description of station locations, see Table 17.
tx represents the mean for all samples, the range is given in parentheses, and n indicates
the total number of samples collected.
-------
TABLE B-7. DISSOLVED POTASSIUM (mg/1), 1970-1977, AT U.S. GEOLOGICAL SURVEY
SAMPLING STATIONS IN THE SAN JUAN RIVER BASIN
Station
Number*
01
02
03
04
05
06
07
08
09
10
11
12
13
14
15
16
17
18
19
20
21
22
1970
x (ain-raax) n
1.0(0.9-1.0)2
—
—
—
—
—
1.4(1.1-1.6)5
2.1(0.8-3.3)8
1.0(0.9-1.0)2
2.0(1.0-2.8)8
2.2(0.6-3.9)4
1.7(1.0-2.8)8
1.7(1.5-1.8)12
2.0(1.8-2.2)3
0.4(0.4-0.4)2
0.6(0.5-0.6)2
2.3(0.9-3.6)9
2.4(0.9-3.4)12
2.3(1.6-3.4)28
2.1(2.0-2.2)2
2.3(1.7-3.3)18
3.5(1.9-8.2)21
1971
x (min-max) n
1.1(0.7-2.4)9
—
~
—
--
—
2.1(1.7-2.6)4
2.4(1.9-2.9)4
1.2(0.6-1.6)9
2.3(2.0-2.6)4
0.6(0.2-1.1)16
2.2(1.7-2.6)4
2.0(1.8-2.9)12
2.4(1.7-3.1)12
0.4(0-0.7)9
0:6(0.1-1.1)9
2.8(1.9-4.0)5
2.8(1.1-4.4)12
2.6(1.2-5.3)48
2.4(2.2-2.7)3
3.0(1.6-6.0)53
3.8(2.3-7.9)12
1972
x (mln-max) n
1.0(0.6-1.2)9
—
—
—
—
—
2.0(1.5-2.9)4
2.7(1.1-4.5)4
1.0(0.7-1.4)9
2.2(1.2-2.9)4
0.6(0.3-1.0)17
2.1(1.4-3.0)4
1.9(1.2-2.3)11
2.3(1.9-3.1)11
0.6(0.3-1.0)9
0.5(0.4-0.8)9
3.1(1.3-4.5)6
2.7(1.8-3.9)11
2.7(1.6-5.0)50
3.1(1.6-4.8)4
3.4(1.7-9.7)50
4.8(3.0-7.4)16
1973
x (min-max) n
0.9(0.7-1.1)9
1.6(-)1
1.6(1.5-1.6)2
2.0(1.8-2.1)2
l-4(-)l
1.4(1.4-1.4)2
2.2(1.8-2.9)5
2.2(2.0-2.412
1.0(0.7-1.4)9
2.0(1.8-2.2)2
0.8(0.4-1.1)15
1.6(1.3-1.9)2
2.0(1.6-2.2)11
2.1(1.8-2.4)11
0.6(0.3-0.7)9
0.7(0.4-1.3)9
2.0(1.3-2.6)2
2.5(1.0-3.9)11
2.0(1.3-3.2)36
1.9(1.8-2.0)2
2.2(1.5-3.5)44
3.0(2.0-5.0)12
1974
x (min-max) n
1.1(0.9-1.3)9
1.6(1.1-1.9)7
1.6(1.1-2.0)7
1.7(1.0-1.9)6
1.2(0.8-1.7)7
1.1(0.8-1.4)7
2.1(1.6-2.6)9
—
1-4(1.2-1.7)9
—
0.9(0.6-1.1)16
2.K-H
1.9(1.5-2.5)12
2.4(1.8-4.0)12
0.9(0.7-1.2)9
0.9(0.8-1.1)9
—
3.6(1.7-4.7)12
2.6(1.7-4.9)36
—
3.0(1.8-6.6)40
3.5(2.0-5.2)11
1975 1976
x (mln-max) n x (win-max) n
1.0(0.7-1.3)9 —
—
—
—
—
—
—
— ,
1.1(0.7-1.4)9
—
0.7(0.5-1.0)14 0.6(0.5-0.8)11
—
2.1(1.8-2.5)13 1.9(1.8-2.1)12
2.4(1.8-3.3)12 2.5(2.0-6.3)12
0.6(0.2-1.2)9 —
0.6(0.3-1.3)9
—
2.9(1.0-3.9)13 3.2(1.3-4.9)12
2.4(0.2-4.9)42 2.4(1.4-5.3)24
—
2.7(1.5-5.0)48 3.0(1.6-6.8)45
3.2(1.6-8.3)13 3.4(2.1-5.2)11
1977
x (mln-max) n
_
_.
«._
__
_
_.
_
_.
0.6(0.5-1.0)9
1.8(1.7-2.0)10
2.1(1.8-2.5)9
—
3.6(2.5-4.6)9
2.5(1.9)-4.4)26
3.6(2.3-5.8)29
3.9(2.3-7.4)11
• . - ~ ' • — •
*For full description of station locations, see Table 17.
fx represents the mean for all samples, the range is given in parentheses, and n indicates
the total number of samples collected.
-------
TABLE B-8. BICARBONATE ION (mg/1), 1970-1977, AT U.S. GEOLOGICAL SURVEY SAMPLING
STATIONS IN THE SAN JUAN RIVER BASIN
oo
Station
Number*
01
02
03
04
05
06
07
08
09
10
11
12
13
14
15
16
17
18
19
20
21
22
1970
x (mln-max) n
24(22-26)2
—
—
—
—
—
72(57-87)5
92(60-127)8
30(25-36)2
108(65-142)8
34(28-41)4
122(80-142)8
88(76-93)12
112(92-130)11
6(6-6)2
40(39-42)2
135(88-176)9
148(91-208)13
128(83-264)64
200(147-254)2
139(25-280)60
173(125-330)21
1971
x (mln-max) n
22(18-28)9
—
—
—
—
—
88(78-108)4
96(63-119)4
29(21-36)9
114(82-141)4
35(19-52)16
134(110-147)4
100(91-113)12
131(95-168)12
9(2-20)9
34(24-52)9
151(104-203)5
160(78-216)12
138(87-257)48
241(184-294)3
153(77-243)53
140(123-195)12
1972
x (mln-max) n
22(16-28)9
—
—
—
—
—
81(70-93)3
108(53-153)4
28(20-38)9
124(61-159)4
33(22-47)16
150(115-172)4
109(102-126)11
132(113-149)11
7(1-13)9
31(21-38)9
153(82-192)6
165(101-239)11
156(102-334)50
218(162-280)4
162(39-290)50
157(73-214)16
1973
x (mln-max) n
25(17-34)9
85(-)l
82(~)2
96(93-100)2
53(-)l
60(55-66)2
94(80-118)5
108(103-113)2
32(22-40)9
116(102-129)2
36(19-45)15
100(94-105)2
100(85-121)11
120(102-145)11
11(2-39)9
30(2-44)9
134(131-138)2
170(96-206)11
124(92-179)36
219(167-271)2
130(94-180)44
147(105-204)12
1974
x (mln-max) n
22(17-27)9
71(34-102)7
72(36-106)7
87(44-111)6
44(28-55)7
45(28-58)7
91(69-117)9
—
29(20-39)9
—
31(17-41)16
143(-)1
94(80-109)12
118(102-147)12
6(2-13)9
30(21-38)9
—
179(96-227)12
138(94-368)36
—
141(48-288)40
136(111-186)11
1975
x (mln-max) n
21(10-35)9
—
--
—
—
—
—
—
28(17-37)9
—
32(16-43)14
~
102(86-112)13
123(98-187)12
9(1-28)9
30(10-42)9
—
168(65-230)13
129(77-247)42
—
137(76-262)48
165(91-399)13
1976 1977
x (mln-max) n x (mln-max) n
—
—
—
—
—
—
—
—
—
__
28(14-52)11 28(19-46)9
—
90(80-96)12 95(92-97)10
123(89-275)12 116(100-130)9
—
—
—
168(82-226)12 182(120-233)9
122(92-193)24 135(79-310)26
—
136(48-220)45 158(82-310)29
168(130-240)11 183(98-240)11
*For full description of station locations, see Table 17.
fx represents the mean for all samples, the range is given in parentheses, and n indicates
the total number of samples collected.
-------
TABLE B-9. SULFATE (mg/1), 1970-1977, AT U.S. GEOLOGICAL SURVEY SAMPLING STATIONS
IN THE SAN JUAN RIVER BASIN
CO
10
Station
Number*
01
02
03
04
05
06
07
08
09
10
11
12
13
14
15
)6
17
18
19
20
21
22
1970
x (nin-max) n
4(3-4)2
—
—
--
—
—
36(20-48)5
54(17-114)8
4(3-4)2
58(19-99)8
7(5-9)4
18(11-26)8
43(35-54)12
120(62-181)11
128(121-135)2
93(87-99)2
84(44-195)9
132(53-196)12
136(54-1000)63
340(145-535)2
189(62-702)60
234(105-378)19
1971
x (mln-max) n
4(1-5)9
—
—
—
—
—
4'>(37-54)4
56(25-76)4
6(4-9)9
59(29-94)4
8(5-14)17
22(16-28)4
47(32-58)12
168(58-330)12
74(36-98)9
64(29-91)9
302(61-120)5
149(54-260)12
137(49-290)47
393(200-590)3
212(86-690)53
295(110-500)13
1972
x (nln-nax) n
5(3-7)9
—
—
—
—
—
49(30-59)4
64(18-93)4
7(5-8)9
75(20-110)4
9(6-18)16
24(19-34)4
55(43-63)11
146(77-200)11
79(26-140)9
66(26-110)9
105*(49-130)6
155(84-250)11
158(83-550)50
415(330-490)4
283(110-1200)50
322(190-700)16
1973
x (tuln-max) n
5(3-8)9
7(-)l
8(7-8)2
26(12-40)2
33(-)l
32(32-33)2
61(46-90)5
64(63-64)2
6(4-8)9
54(35-73)2
8(4-14)15
16(15-16)2
52(40-70)11
98(65-190)11
99(30-220)9
80(32-150)9
79(62-96)2
134(47-220)11
87(46-180)36
285(160-410)2
120(56-230)44
191(67-380)12
1974
x (nln-aax) n
5(3-7)9
7(5-9)7
7(5-9)7
12(8-32)6
28(14-36)7
28(12-37)7
45(27-54)9
—
6(4-7)9
—
8(6-10)16
33(-)l
50(42-58)12
143(66-320)12
99(30-200)9
77(33-130)9
—
204(78-320)12
160(60-770)36
—
210(110-520)40
299(170-410)11
1975 1976
x (nln-nax) n x (min-max) n
4(3-8)9 —
—
_-
_-
„
_-
__
—
5(3-7)9
_-
8(4-13)13 10(4-14)11
—
55(27-72)13 49(40-60)12
118(72-250)12 169(85-700)12
109(25-250)9
72(34-130)9
— '
149(36-224)13 179(44-300)12
107(49-280)42 137(56-430)24
_.
154(58-330)48 217(65-550)45
315(67-1600)13 275(140-430)11
1977
x (mln-max) n
—
—
—
—
—
—
—
—
—
—
14(7-46)9
—
49(45-56)10
149(85-190)9
—
—
—
240(140-390)9
170(97-610)26
—
304(150-670)29
387(200-640)11
*For full description of station locations, see Table 17.
fx represents the mean for all samples, the range is given in parentheses, and n indicates
the total number of samples collected.
-------
TABLE B-10. CHLORIDE (mg/1), 1970-1977, AT U.S. GEOLOGICAL SURVEY SAMPLING STATIONS
IN THE SAN JUAN RIVER BASIN
Station
Number*
01
02
03
04
05
06
07
08
09
10
11
12
13
14
15
16
17
18
19
20
21
22
1970
x (mln-max) n
2(2-2)2
—
—
—
—
—
1(0-1)5
2(0-4)8
2(1-3)2
2(0-3)8
1(0-2)4
3(1-4)8
2(1-6)12
3(2-4)11
1(1-1)2
2(1-2)2
13(3-26)9
13(3-22)12
7(3-17)63
16(6-26)2
11(3-86)60
22(7-120)21
1971
x (roin-max) n
1 (0-1)9
—
—
—
—
—
2(1-3)4
2(1-4)4
1(0-2)9
4(3-7)4
1(0-2)16
4(2-6)4
3(2-7)12
5(2-8)12
1(0-1)9
1(0-1)9
13(6-21)5
16(4-24)12
10(4-20)47
19(10-29)3
1.6(6-45)53
19(8-41)12
1972
x (mtn-max) n
1(0-2)9
—
—
—
—
—
1(1-2)4
4(2-5)3
1(0-1)9
3(2-4)4
2(0-10)16
4(3-6)4
3(3-5)11
6(3-18)11
2(0-12)9
2(0-14)9
19(6-29)6
17(8-30)11
9(4-50)50
16(7-25)4
17(8-72)50
20(12-37)16
1973
x (min-max) n
1(0-2)9
K-)l
1(0-1)2
1(1-1)2
K-)l
1(0-1)2
1(1-2)5
2(2-2)2
2(0-6)9
2(2-2)2
1(0-2)15
2(3-2)2
4(2-6)11
5(4-12)11
1(0-1)9
1(0-2)9
10(5-15)2
16(4-32)11
6(3-14)36
12(6-19)2
8(3-17)44
16(5-37)12
1974
x (mln-max) n
1(0-2)9
1(0-1)7
1(0-1)7
1(0-2)6
1(0-1)7
1(0-2)7
1(1-2)9
—
6(4-7)9
—
1(0-3)16
6(-)l
3(2-6)12
5(4-6)12
1(0-1)9
1(0-1)9
--
24(8-33)12
10(3-19)36
—
15(8-27)40
25(10-40)11
1975 1976 1977
x (mln-max) n x (mln-max) n x (mln-max) n
1(0-2)9
—
—
—
—
—
—
—
5(3-7)9
—
1(0-1)13 1(0-1)13 0.6(0,4-1.2)9
—
3(2-4)13 3(2-3)12 3(2-3)10
4(2-7)12 4(3-11)12 5(3-8)9
1(0-1)9
1(0-2)9
—
17(3-29)13 20(4-29)12 26(15-38)9
7(3-15)42 7(3-16)24 21(4-160)26
—
10(4-21)48 17(4-44)45 23(13-63)29
16(4-44)13 18(9-28)11 29(15-59)11
-
*For full description of station locations, see Table 17.
|x represents the mean for all samples, the range is given in parentheses, and n indicates
the total number of samples collected.
-------
TABLE B-ll. DISSOLVED SILICA (ing/1), 1970-1977, AT U.S. GEOLOGICAL SURVEY SAMPLING
STATIONS IN THE SAN JUAN RIVER BASIN
Station
Number*
01
02
03
04
05
06
07
08
09
10
11
12
13
14
15
16
17
18
19
20
21
22
1970
x (mln-raax) n
17(16-18)2
—
—
—
—
—
22(19-24)5
17(16-21)8
22(22-23)2
15(10-16)8
3(3-4)4
5(3-8)8
11(10-12)12
12(10-15)11
10(10-11)2
7(6-8)2
8(6-12)9
7(5-9)12
11(6-27)63
—
10(4-15)60
11(6-20)21
1971
x (mln-max) n
17(15-18)9
—
—
—
—
—
24(22-27)4
18(17-21)4
19(16-22)9
15(13-17)4
4(3-5)16
7(5-9)4
12(11-13)12
11(9-13)12
8(4-10)9
6(4-7)9
9(7-12)5
7(6-9)12
11(6-17)48
12(9-14)3
10(1-15)53
11(9-13)12
1972
x (min-max) n
17(13-23)9
—
—
—
__
—
23(20-26)4
17(16-18)4
20(17-26)9
14(13-16)4
4(3-5)16
5(2-7)4
12(11-14)11
11(9-14)11
7(4-10)9
6(4-8)9
9(4-18)6
8(6-10)11
10(4-17)50
11(8-13)4
10(0-23)50
10(6-15)13
1973
x (min-max) n
16(14-19)9
24(-)l
22(20-24)2
18(14-22)2
27(-)l
23(19-27)2
22(16-26)5
15(13-17)2
19(15-21)9
12(10-15)2
4(2-5)15
6(6-7)2
11(9-12)11
11(9-12)11
8(4-12)9
6(4-10)9
7(6-8)2
7(6-9)11
9(5-13)36
10(9-11)2
8(3-14)44
10(8-12)12
1974
x (mln-max) n
15(10-17)9
22(18-26)7
22(18-26)7
20(17-23)6
24(18-29)7
24(18-29)7
23(18-26)9
—
17(0-22)9
—
5(3-24)16
4(-)l
10(6-12)12
10(9-13)12
8(2-12)9
6(3-8)9
—
8(6-10)12
12(4-33)36
—
10(3-37)39
8(4-12)11
1975 1976 1977
x (raln-raax) n x (mln-max) n x (min-max) n
16(14-18)9
—
—
—
„
__
-_
—
17(15-20)9 — -—
—
4(3-4)14 3(2-4)11 3(3-4)9
—
10(6-12)13 9(1-10)12 10(9-11)10
10(8-11)12 9(7-10)12 10(9-12)9
8(4-13)9
6(4-7)9
__
7(5-9)13 7(6-9)12 7(5-9)9
9(5-12)42 9(6-11)24 10(4-16)26
—
9(4-15)48 7(0-12)45 9(1-18)29
9(6-10)13 9(7-11)11 8(2-11)11
*For full description of station locations, see Table 17.
fx represents the mean for all samples, the range is given in parentheses, and n indicates
the total number of samples collected.
-------
TABLE B-12. TOTAL HARDNESS (CaC03, mg/1), 1970-1977, AT U.S. GEOLOGICAL SURVEY
SAMPLING STATIONS IN THE SAN JUAN RIVER BASIN
•P.
PO
Station
Number*
01
02
03
04
05
06
07
08
09
10
11
12
13
14
15
16
17
18
19
20
21
22
1970
x (min-max) n
17(18-16)2
—
~
—
—
—
78(55-99)5
94(48-160)8
23(22-24)2
123(67-176)8
34(28-38)4
90(61-106)8
90(85-94)12
143(100-177)11
122(115-130)2
118(112-124)2
197(140-304)9
221(121-320)13
172(108-565)64
457(238-676)2
223(124-600)60
258(196-502)21
1971
x (mfn-max) n
15(11-19)9
—
—
—
—
—
92(85-99)4
96(55-120)4
21(15-25)9
125(90-160)4
33(16-48)16
102(86-110)4
101(86-110)12
170(100-210)12
73(38-96)9
85(42-120)9
202(140-240)5
241(98-350)12
179(97-270)48
543(320-740)3
240(130-610)53
302(180-430)12
1972
x (mln-max) n
16(13-20)9
—
—
—
—
—
100(70-120)4
109(46-140)4
20(15-21)9
144(58-190)4
33(20-44)17
110(88-130)4
106(100-120)11
168(120-200)11
78(34-130)9
86(39-130)9
207(100-250)6
246(140-370)11
201(130-390)50 '
495(360-670)4
275(120-800)50
306(210-460)16
1973
x (mln-max) n
18(11-26)9
52(-)l
52(50-55)2
84(71-97)2
61(-)1
64(61-66)2
122(100-160)5
125(120-130)2
23(13-30)9
130(110-150)2
34(15-50)15
86(83-90)2
108(89-120)11
138(120-150)11
102(32-210)9
99(47-160)9
170(160-180)2
239(110-350)11
145(100-230)36
410(260-560)2
169(110-260)44
232(120-300)12
1974
x (mln-mnx) n
16(12-21)9
48(24-67)7
48(25-71)7
63(36-83)6
58(28-64)7
50(30-65)7
100(70-120)9
—
21(16-28)9
—
33(18-42)16
110(-)1
106(93-110)12
160(120-240)12
103(90-210)9
104(53-140)9
—
307(150-410)12
178(110-490)36
—
228(150-420)40
318(180-400)11
1975
x (mln-max) n
17(11-25)9
—
—
—
~
—
—
—
20(11-29)9
—
36(18-71)14
—
108(84-120)13
146(110-190)12
111(30-250)9
97(50-170)9
—
254(82-370)13
151(100-240)42
—
194(110-310)48
247(120-420)12
1976 1977
x (mln-max) n x (mln-max) n
—
—
—
—
__
—
—
—
—
-_
33(12-52)11 38(23-54)9
-_
97(90-100)12 98(94-100)10
161(120-350)12 161(120-190)9
_.
—
—
277(100-370)12 322(210-470)9
167(110-320)24 192(140-420)26
—
230(120-400)45 287(180-560)29
291(100-450)12 366(240-520)11
*For full description of station locations, see Table 17.
tx represents the mean for all samples, the range is given in parentheses, and n indicates
the total number of samples collected.
-------
TABLE B-13. TOTAL IRON (yg/1), 1970-1976, AT COLORADO STATE HEALTH
DEPARTMENT SAMPLING STATIONS IN THE SAN JUAN RIVER BASIN
Station
Number*
S-01
S-02
S-03
S-04
S-05
S-06
S-07
S-08
S-09
S-10
S-ll
S-12
S-13
1970
x (nln-max) nt
—
—
350(100-1350)6
483(50-2300)7
225(100-500)6
458(50-800)6
533(50-2600)6
—
224(50-700)5
—
158(80=-250)6
293(50-700)7
117(0-250)6
1971
x (mtn-max) n
95(50-150)4
225(50-400)4
268(100-4400)5
966(50-4200)5
720(100-2200)5
150(50-200)3
450(50-1600)5
60(20-100)4
210(20-600)4
125(50-200)4
238(50-500)4
288(20-1000)5
95(50-150)4
1972
x (min-max) n
100(50-150)3
150(100-200)4
175(100-250)2
150(0-250)3
300(200-300)3
200(100-350)3
125(50-200)2
25(0-50)4
25(0-50)2
100(50-150)4
a 2
25X0-50)2
117(0-300)3
1973
x (min-max) n
350(-)1
900 (-)l
1000 (-)l
600 (-)l
450(-)1
500 (-)l
200 (-)l
50(0-100)2
350 (-)l
300 (-)l
--
100 (-)l
100(-)1
1974
x (min-max) n
200(100-300)2
225(150-300)2
100(0-200)3
175(150-600)2
275(150-600)4
350(100-550)3
60(0-100)3
a** 2
100(0-200)3
50(0-100)3
50(0-100)2
100(0-200)3
83(0-150)3
1975
x (min-max) n
470(200-1100)6
1233(100-6200)6
8125(200-42000)6
875(0-1950)6
3750(300-9700)5
962(400-1600)5
1050(100-4000)6
83(0-250)6
1808(100-4200)6
217(0-370)6
11875(0-48000)6
3490(350-10000)5
9850(300-42000)6
1976
x (min-max) n
454(120-1100)7
451(150-760)7
2186(130-4800)7
628(0-1000)6
1418(170-5500)7
743(420-1400)7
1084(100-5100)7
78(0-190)5
332(180-600)5
180(0-440)5
2722(100-11300)6
1550(900-2600)6
2587(420-8700)6
•
*For full description of station locations, see Table 18.
**Indicates samples this station and date did not contain
detectable levels of iron.
tx represents the mean for all samples, the range is given in parentheses,
and n indicates the total number of samples collected.
-------
TABLE B-14. TOTAL MANGANESE (yg/1), 1970-1976, AT COLORADO STATE HEALTH
DEPARTMENT SAMPLING STATIONS IN THE SAN JUAN RIVER BASIN
Station
Number*
S-01
S-02
S-03
S-04
S-05
S-06
S-07
S-08
S-09
S-10
S-ll
S-12
S-13
1970
x (min-max) n^
—
—
a 6
a 6
3(0-20)6
161(100-350)7
20(0-70)5
—
5(0-300)6
—
31(0-170)7
a 6
65(0-420)7
1971
x (min-max) n
a** 4
12(0-50)4
a 4
a 4
a 5
167(100-200)3
12(0-50)4
a 4
a 5
a 4
12(0-50)4
a 4
38(0-150)4
1972
x (mln-max) n
a 3
a 2
a 3
50(0-150)3
a 2
150(150-150)2
a 2
a 2
a 3
a 2
a 2
a 3
a 3
1973
x (mln-mnx) n
a 1
a ]
a 1
a 1
a 1
150(-)1
a 1
a 3
a 1
a 1
—
a 1
a 1
1974
x (mln-max) n
a 2
30(0-60)2
a 2
a 2
17(0-50)3
383(50-800)3
a 2
a 2
60(0-150)3
a 2
50(0-100)2
15(0-30)2
220(40-400)2
1975
x (mln-max) n
tK 0-50)6
33(0-200)6
133(0-750)6
17(0-100)6
110(0-400)5
290(150-600)5
49(0-250)6
a 6
150(0-250)6
8(0-50)6
275(0-1200)6
440(0-1300)5
241(0r400)6
1976
x (rain-max) n
34(0-100)5
68(0-240)5
148(0-400)5
31(0-70)7
396(110-1100)5
366(180-600)5
398(70-1000)5
a 3
128(0-420)5
a 3
162(0-580)6
368(0-1200)5
277(50-480)6
*For full description of station locations, see Table 18.
**Indicates samples this station and date did not contain
detectable levels of manganese.
tx represents the mean for all samples, the range is given in parentheses,
and n indicates the total number of samples collected.
-------
TABLE B-15.
CONCENTRATIONS OF TRACE ELEMENTS (yg/1) AT SELECTED COLORADO
STATE HEALTH DEPARTMENT SAMPLING STATIONS (Samples collected from
March 1968 to April 1976 unless otherwise indicated.)
San Juan River
above
Element Navajo Reservoir
Piedra River
Northeast of
Atboles, CO
Los Piffos River
ne.ir
LaBoc.i
Antraas River
near
Bondad, CO
San Juan River
near
State line
Me Elmo Creek
West of
State line
Arsenic, total
(01/68-04/76)
Boron, total
Cadmium, total
Chromium, total
Copper, total
Iron, total
Lead, total
Manganese , total
Mercury, total
Molybdenum, total
(02/71-04/76)
Selenium, total
(01/68-04/76)
Silver, total
(11/68-04/76)
Zinc, total
n x max
8 0.2 50
0 44 150
0 a a
27 a a
27 a a
42 1,622 42,000
27 3.2 50. O
41 32 750
7 0.11 0.40
14 a a
28 0.2 4.0
15 a a
41 13 150
n x max
27 a a
29 34 150
39 a a
27 a a
27 a a
43 485 4,200
27 0.4 10.0
41 8 150
7 0.14 0.5
14 a a
29 0.2 3.0
15 a a
41 16 400
n x max
27 a a
30 33 160
40 0.1 3.0
27 a a
27 a a
43 820 9,700
27 3.7 10.0
45 56 1,100
6 0.07 0.4
14 1.4 10.0
28 0.8 8.0
15 a a
41 25 800
n x max
27 a a
31 85 900
37 a a
28 a a
28 2 60
42 496 5,100
28 4.8 45.0
39 72 1,000
5 0.10 0.
15 0.7 10.
29 0.3 4.0
15 a a
39 29 220
ti x max
28 0.4 10.0
29 81 260
37 <0.1 1.0
27 a a
27 11 300
40 2,970 100,000
27 6.7 70.0
38 65 1,300
8 0.16 1.20
13 1.9 10.0
39 1.4 14.0
14 a a
39 61 700
n x max
28 0.8 20.0
39 200 760
36 a a
24 a a
24 a a
40 1,683 42,000
24 6.3 67 .0
39 77 420
4 a a
13 3.8 70.0
40 6.8 20.0
13 a a
38 67 800
tn
*x represents the mean for all samples, n indicates the total number of samples collected,
and a indicates samples this station and date did not contain detectable levels of the
specified trace element.
-------
TABLE B-16.
AMBIENT LEVELS OF TOTAL PHOSPHORUS AND DISSOLVED ORTHO-
PHOSPHORUS (ug/1), 1973-1976, AT SELECTED U.S. GEOLOGICAL
SURVEY SAMPLING STATIONS IN THE SAN JUAN RIVER BASIN
Total phosphorus
1973
1974
1975
1976
Dissolved
orthophosphorus
1973
1974
1975
1976
San Juan River
at
Arrhuleta
x (min-max) n
52(30-90)11
35(0-80)12
35(10-120)12
17(0-30)12
19(0-50)11
6(0-10)12
10(0-30)13
4(0-4)12
Anlnag River
at
Farmlngton
x (mln-max) n
114(20-280)11
401(30-1900)12
335 (0-2800) 12
142(30-870)12
10(0-30)12
19(0-50)12
11(0-30)12
11(0-50)13
San Juan River
at
Farmington
x (mln-m,ix) n
224(50-1200)11
278(30-1800)8
—
—
19(0-60)11
20(0-80)8
6(0-20)11
20(0-60)10
San Juan River
at
Shiprock
x (min-max) n
298(70-1400)11
906(40-6400)12
427(80-2400)12
328(70-1200)12
28(0-70)12
33(10-90)12
28(0-160)23
26(0-80)41
San Juan River
near
Bluff
x (mln-max) n
—
360(140-800)3
526(60-2000)12
2000(90-18000)12
22(0-80)12
21(0-211)9
—
—
tx represents the mean for all samples, the range is given in parentheses,
and n indicates the total number of samples collected.
-------
TABLE B-17.
AMBIENT LEVELS OF NITRATE-NITRITE, TOTAL KJELDAHL, AND AMMONIA
(yg/1), 1973-1976, AT SELECTED U.S. GEOLOGICAL SURVEY SAMPLING
STATIONS IN THE SAN JUAN RIVER BASIN
Nitrate-nitrite
1973
1974
1975
1976
Total Kjeldahl
-ps.
-vl 1973
1974
1975
1976
Ammonia
1973
1974
1975
1976
San Juan River
at
Archuleta
x (min-max) n
78(0-180)9
71(30-150)12
94(40-180)12
98(10-390)12
796(310-3800)9
272(120-390)11
296(140-470)12
278(90-480)12
56(20-100)9
38(10-70)12
f»(0- 50)12
11(0-30)12
Anlmas River
at
Farmlngton
x (min-max) n
132(10-320)9
388(60-2000)12
172(10-520)12
194(10-490)12
760(170-4300)11
2236(80-14000)11
963(40-5500)12
698(50-4700)12
104(10-540)11
108(10-440)12
35(0-130)12
32(0-150)12
San Juan River
at
Fannington
X (rain-max) n
156(30-290)9
171(80-370)8
580(-)1
185(140-230)2
894(220-3900)11
925(230-4500)8
—
—
80(20-220)11
105(20-330)8
—
—
San Juan River
at
Shiprock
x (min-max) n
283(110-370)9
558(260-1000)12
486(100-890)12
614(190-1400)12
1171(240-4600)11
1954(250-14000)11
1032(200-3300)12
1068(210-5400)12
104(30-510)11
141(40-890)12
79(0-570)12
30(0-120)12
San Juan River
near
Bluff
x (min-max) n
—
1370(1300-1400)3
572(110-1300)12
908(290-1700)12
—
717(200-1500)3
942(490-3100)13
1439(150-4000)11
—
—
—
tx represents the mean for all samples, the range is given in parentheses,
and n indicates the total number of samples collected.
-------
TABLE B-18. TEMPERATURE (°C), 1970-1977, AT U.S. GEOLOGICAL SURVEY SAMPLING
STATIONS IN THE SAN JUAN RIVER BASIN
oo
Station
Number*
or
02
03
04
05
06
07
08
09
10
11
12
13
14
15
16
17
18
19
20
21
22
1970
x (mln-max) n
6,5(5,0-8.0)2
—
—
—
--
—
5.5(0-12.5)5
8.5(0-20.0)8
7.5(6.0-9.0)2
9.5(0-21.5)8
3.0(0-10.0)8
10.1(0-24.5)8
8.3(5.0-14.0)12
11.8(3.2-23.5)11
1.5(0-3.0)2
5.0(4.0-6.0)2
7.9(0-24.5)12
9.7(0.6-20.0)13
10.0(3.5-14.0)25
8.3(0-17.0)7
12.4(4.5-28.5)13
14.6(2.0-29.0)27
1971
x (min-max) ri
7.4(2.0-14.0)9
—
—
—
—
—
7.1(0-20.5)4
7.2(0-20.5)4
9.2(4.0-18.0)9
8.4(0-20.5)4
4.8(0-11.0)21
10.8(0-22.5)4
7.4(4.0-11.5)12
13.3(4.5-28.0)13
6.0(1.0-12.0)10
8.6(5.0-15.0)9
8.9(0.5-19.5)12
13.0(1.5-26.5)23
11.5(3.5-27.0)24
9.8(0-22.0)4
14.8(0-30.0)31
15.1(0.5-28.0)30
1972
x (mln-max) n
7.4(2.0-16.0)9
15.6(7.0-22.0)5
16.6(7.0-22.0)5
18.0(11.0-22.0)5
16.0(10.0-22.0)4
13.8(7.0-21.0)5
12.4(0-22.0)9
7.5(0-18.0)4
8.6(7.0-12.0)9
9.0(0.5-17.0)4
4.9(0-12.0)18
10.5(0.5-18.0)4
9.8(6.0-13.0)11
13.2(2.5-24.5)11
8.1(2.0-12.0)9
8.3(1.0-16.0)9
11.6(1.5-24.0)11
13.0(0-27.5)18
13.3(2.0-26.0)24
11.3(0-22.0)14
11.8(0.5-28.0)24
12.6(0-29.0)21
1973
x (min-max) n
5.2(1.0-12.0)9
9.3(6.5-18.5)6
7.5(3.0-14.5)7
11.6(8.0-21.0)5
9.3(4.0-17.0)6
11.2(2.5-16.5)7
12.6(0-21.5)9
15.2(8.5-22.0)2
8.2(3.0-14.0)9
11.0(5.0-17.0)2
5.0(0-11.0)19
16.5(11.0-22.0)2
8.4(5.0-11.0)11
8.5(4.0-13.0)11
4.8(1.0-9.0)9
7.2(5.0-12.6)9
9.9(1.5-20.0)8
10.1(2.0-20.5)20
9.7(3.0-18.0)22
6.3(0-18.0)10
9.4(0.5-19.5)24
11.5(0-21.5)25
1974
x (mtn-max) n
7.0(1.0-17.0)9
10.8(5.6-16.0)13
10.6(3.9-18.5)15
13.8(5.5-21.5)13
10.5(5.0-17.0)16
9.^2(4.0-14.0)16
]2. 5(0-21. 0)18
—
9.6(1.0-16.0)9
—
4.5(0-15.0)17
19.5(-)1
8.2(4.5-13.0)12
12.3(4.5-22.5)12
4.6(1.0-10.0)9
6.6(2.0-12.0)9
—
12.1(0.5-25.0)18
11.4(2.5-23.0)19
—
12.2(1.0-25.0)16
11.1(0-25.5)23
1975
x (min-max) n
7.9(2.0-18.0)9
—
—
—
—
—
—
—
6.6(2.0-12.0)9
—
4.4(0-13.0)14
—
6.7(2.0-11.0)13
9.4(0.5-19.0)11
5.4(1.0-12.0)9
6.8(2.0-11.0)9
12.5(-)1
9.8(0.5-21.0)23
9.0(0-19.0)13
—
10.9(0-20.0)21
12.9(0-22.0)19
1976 1977
x (min-max) n x (min-msx) r
__
—
„
__
—
—
—
—
__
—
4,4(0-14.0)11 0.5(0-1.0)2
--
6.4(4.0-8.0)12 9.0(5.5-14.0)10
11.8(4.0-20.0)12 4.8(4.0-5.5)2
-_
—
__
11.0(1.0-24.0)12 14(0-22)9
11.4(3.0-22.5)12 11.5(2.5-22.0)13
3.2(3.0-3.5)2
8.9(1.5-18.0)12 13.8(3.0-24.5)11
3.2(0-26.0)2 14.3(0-29)11
*For full description of station locations, see Table 17.
fx represents the mean for all samples, the range is given in parentheses, and n indicates
the total number of samples collected.
-------
TABLE B-19. DISSOLVED OXYGEN (mg/1), 1970-1977, AT U.S. GEOLOGICAL SURVEY SAMPLING
STATIONS IN THE SAN JUAN RIVER BASIN
Station
Number*
01
02
03
04
05
07
08
09
10
11
12
13
14
15
16
17
18
19
20
21
22
1970
x (•In-nax) n
—
—
—
—
—
10.0(8.2-11.5)5
9.6(7.6-11.3)8
—
9.7(8.9-11.6)8
12.1(10.0-14.2)2
9.4(7.2-11.8)8
11.0(9.5-12.9)12
—
—
—
9.9(7.8-13.8)11
9.9(7.9-12.5)10
9.5(6.8-11.7)24
10.0(7.7-12.3)3
8.8(6.0-11.0)12
9.6(6.6-11.6)4
1971
x (mln-max) n
—
—
—
—
—
10.3(7.2-12.4)5
10.4(7.9-11.8)4
~
10.1(6.9-12.4)4
10.0(9.2-12.2)11
9.9(7.2-12.4)4
11.2(9.6-12.6)12
—
—
—
10.2(5.8-12.3)12
9.4(8.3-10.4)6
9.2(6.9-12.1)24
8.6(7.3-12.0)3
9.3(7.5-11.0)12
9.4(6.7-11.6)11
1972
x (min-max) n
—
—
—
—
—
9.7(6.6-12.2)4
10.1(8.4-11.7)4
—
9.8(8.6-11.1)4
10.2(9.0-12.2)16
9.6(7.6-12.1)4
12.2(10.4-15.3)11
—
—
—
9.6(8.5-11.6)11
9.5(8.0-12.2)11
9.4(7.9-12.2)23
8.8(6.0-11.0)4
9.8(7.7-12.1)12
9.0(7.8-12.4)13
1973
x (nlti-Bax) n
9.0(7.8-10.2)4
—
9.3(-)l
9.5(-)l
9.4C-JI
9.2(7.1-11.2)4
8.6(7.1-10.1)2
8.6(8.0-9.4)4
9.2(8.1-10.2)2
9.7(8.4-11.8)14
8.4(7.6-9.2)2
11.5(10.1-13.4)11
—
7.9(6.6-7.8)4
7.8(6.5-9.0)4
9.2(7,3-11.4)8
9.4(7.6-12.8)11
9.6(8.5-11.6)22
10.6(9.0-12.1)2
9.6(7.7-11.5)11
8.4(1.3-11.6)11
1974
x (sln-max) n
9.9(9.4-10.8)9
8.2(-)l
9.0(-)1
—
—
8.4(7.0-11.1)3
—
9.6(7.9-10.2)9
—
9.3(6.8-11.2)14
—
10.9(10.0-12.6)11
10.3(10.0-10.5)3
9.1(7.5-10.2)9
8.9(7.5-10.4)9
—
9.0(6.0-12.4)10
9.1(6.9-11.1)18
9.0(6.4-11.2)9
10.1(7.7-12.1)10
10.9(9.0-14.0)9
1975 1976
x (Bin-isax) n x (mln-max) n
11.2(9.0-11.3)9
—
—
—
—
—
—
10.3(9.0-11.2)9
_-
9.8(9.6-9.9)2 10.3(9.9-10.7)2
—
11.1(9.1-12.5)12 12.1(11.0-13.5)7
9.9(7.5-12.5)10 9.9(5.5-12.0)9
9.9(8.9-10.6)9 —
10.0(8.6-11.0)9
—
10. 0(7. 1-13. 0)11 10.6(9.1-12.4)8
9.9(7.2-12.5)12 5.7(6.4-11.2)8
_-
10.3(7.9-12.8)12 10.7(7.8-13.0)8
9.3(7.9-10.4)6 9.6(5.5-14.4)9
1977
x (nln-max) n
—
—
—
—
—
—
—
—
—
10.6(-)1
—
11.0(6.6-13.2)8
10. 9(10. 9-10. 9)2
—
—
—
9.2(6.5-12.6)7
10.1(8.2-12.4)8
—
10.7(7.5-14.5)8
8.6(6.3-10.6)10
*For full description of station locations, see Table 17.
tx represents the mean for all samples, the range is given in parentheses, and n indicates
the total number of samples collected.
-------
TABLE B-20. pH, 1970-1977, AT U.S. GEOLOGICAL SURVEY SAMPLING STATIONS IN THE
SAN JUAN RIVER BASIN
Station
Number*
01
02
03
04
OS
06
07
08
09
10
I—1
cn n
0 u
12
13
14
15
16
17
18
19
20
21
22
1970
x (mln-nax) n
7.4(6.9-7.8)2
—
—
—
—
—
7.9(7.5-8.5)5
8.0(7.1-8.8)8
7.4(7.1-7.6)2
7.2(7.6-9.2)8
7.8(7.5-8.3)4
8.1(7.6-8.7)8
8.3(7.3-9.5)12
8.0(7.4-8.3)11
6.8(6.8-6.9)2
7.2(7.2-7.3)2
8.2(7.5-8.8)12
8.1(7.6-8.7)13
7.7(7.1-8.7)64
8.0(7.5-8.3)4
7.9(7.3-8.7)60
7.7(7.1-8.4)21
1971
x (mln-max) n
7.6(7.0-8.9)9
—
—
—
—
—
8.0(7.5-8.6)4
8.1(7.7-8.5)4
7.6(7.1-8.7)9
7.9(7.4-8.1)4
7.8(7.1-9.0)18
8.2(7.8-8.8)4
8.2(7.5-9.2)12
7.9(7.3-8.7)12
5.8(5.1-6.8)9
7.2(6.9-7.8)9
8.3(7.6-8.9)12
7.9(7.4-8.5)12
7.9(6.9-8.6)54
8.1(7.9-8.6)3
7.9(7.3-8.7)54
7.8(7.2-8.5)15
1972
x (Bin-man) n
7.2(6.7-8.0)9
—
—
—
—
—
8.1(7.2-8.7)4
8.0(7.4-8.4)4
7.2(6.6-7.9)9
8.1(7.0-8.8)4
7.2(6.5-9.6)17
8.3(7.6-8.9)4
8.4(7.5-9.3)11
8.0(7.3-8.4)11
6.8(5.2-8.8)9
7.0(6.8-7.2)9
8.2(7.4-8.8)11
8.2(7.3-9.1)11
7.9(6.9-8.7)62
7.9(7.3-8.8)5
7.9(7.2-8.5)50
7.6(6.9-8.3)18
1973
x (min-max) n
7.7(7.1-8.2)9
8.0(-)1
8.0(8.0-8.1)2
8.2(7.9-8.4)2
8.0(-)1
7.8(7.8-7.8)2
8.4(8.0-9.1)5
8.2(7.7-8.9)2
7.7(7.2-8.2)9
8.1(7.8-8.3)2
7.8(6.6-9.5)15
8.5(8.0-8.9)2
8.4(8.1-9.0)11
7.8(7.0-8.2)11
7.3(6.6-8.6)9
7.5(6.9-8.2)9
8.3(7.8-8.7)8
8.2(7.9-8.8)11
8.0(7.4-8.4)47
8.2(7.8-8.5)2
8.1(7.5-8,6)45
8.0(7.3-8.4)12
1974
x (mln-max) n
7.9(7.3-8.6)9
7.8(7.7-8.1)4
7.8(7.7-8.1)4
8.1(8.0-8.2)3
7.8(7.5-8.0)4
7.7(7.5-7.9)4
8.1(7.8-8.8)9
—
7.9(7.4-8.5)9
—
7.9(7.2-8.4)14
8.3(-)l
8.6(7.7-9.5)12
8.2(7.6-8.7)12
7.2(5.8-8.0)9
7.7(7.3-8.0)9
—
8.4(7.7-8.9)12
8.0(7.6-8.8)41
—
8.2(7.5-9.0)40
8.0(7.5-8.4)13
1975
x (nin-nax) n
8.2(7.6-8.5)9
—
—
—
—
—
—
—
8.3(7.3-8.8)9
—
8.1(7.8-8.4)13
—
8.2(7.6-8.9)13
8.1(7.7-8.4)11
7.8(7.1-8.6)7
7.7(7.2-8.3)8
—
8.2(7.9-8.9)13
7.9(7.2-8.4)29
—
8.2(7.6-8.9)27
8.2(7.9-8.5)13
1976 1977
x (mln-max) n x (min-max) n
_-
—
—
—
-_
—
__
__
__
__
7.4(6.5-8.5)11 6.6(6.5-6.6)2
„
8.0(7.2-8.7)12 8.1(7.8-8.7)10
8.1(7.3-9.0)12 7.6(7.6-7.6)2
—
__
—
8.2(7.8-8.5)12 3.0(7.8-8.6)9
8.3(7.5-8.6)23 7.9(7.1-8.7)26
„
8.0(7.1-9.0)41 8.0(7.0-8.7)30
8.2(7.2-8.5)11 3-2(8.0-8.4)11
*For full description of station locations, see Table 17.
tx represents the mean for all samples, the range is given in parentheses, and n indicates
the total number of samples collected.
-------
TABLE B-21. TOTAL ALKALINITY (CaC03, mg/1), 1970-1977, AT U.S. GEOLOGICAL SURVEY
SAMPLING STATIONS IN THE SAN JUAN RIVER BASIN
Station
Number*
OJ
02
03
04
05
06
07
08
09
10
11
12
13
14
15
16
17
18
19
20
21
22
1970
x (nln-nax) n
20(18-21)2
—
—
—
—
—
60(47-71)5
76(49-104)8
26(21-30)2
89(67-168)8
30(23-34)4
100(66-116)8
75(74-77)12
93(75-107)11
5(5-5)2
13(32-34)2
113(72-144)9
122(75-171)13
106(70-217)63
162(116- 208)2
114(21-230)60
150(102-315)21
1971
x (min-max) n
18(15-23)9
—
—
~
—
—
73(64-89)4
80(52-98)4
24(17-30)9
94(90-160)4
28(16-43)16
110(90-121)4
83(75-93)12
108(78-13B)12
8(2-16)9
28(20-43)9
124(85-167)5
132(64-177)12
113(79-208)48
198(151-241)1
126(63-199)53
128(101-160)12
1972
x (nln-nax) n
18(13-23)9
—
—
—
~
,--
66(57-76)3
88(43-125)4
23(16-31)9
102(58-190)4
28(18-39)16
121(94-141)4
90(85-103)11
108(93-122)11
7(J-10)9
26(17-31)9
125(67-157)6
135(83-196)11
128(84-274)50
179(133-230)4
131(32-238)50
128(60-176)16
1973
x (nin-max) n
21(14-28)9
70(-)1
67(63-71)2
80(76-84)2
43(-)l
50(45-54)2
84(71-98)5
92(84-99)2
26(18-33)9
95(84-106)2
29(16-38)15
88(77-99)2
90(72-104)10
108(84-119)11
9(2-32)9
24(2-36)9
114(113-116)2
139(79-169)11
102(75-140)36
180(137-222)2
107(78-153)44
121(86-167)12
1974
x (mln-max) n
16(13-22)9
58(28-84)7
59(30-87)7
71(36-91)6
36(23-45)7
37(23-48)7
75(58-89)9
—
24(18-32)9
—
26(14-34)16
1I7(-)1
80(75-89)12
98(84-119)12
5(3-11)9
25(17-31)9
~
147(79-186)12
113(82-302)36
—
116(80-236)40
127(91-153)11
1975 1976 1977
x (nln-nax) n x (nln-max) n x (mln-nax) n
17(8-29)9
—
—
—
—
—
—
—
23(14-30)9
— —
26(13-35)14 25(11-43)11 32(26-38)2
—
84(71-93)13 75(64-79)12 78(76-80)10
101(84-121)12 102(80-153)12 88(87-89)2
7(1-23)9
24(34-140)9
— —
137(53-189)13 138(67-185)12 149(98-191)9
106(34-203)42 100(80-110)24 112(75-250)26
—
113(62-215)48 112(49-180)45 130(74-250)29
122(75-154)12 138(107-156)12 153(80-200)11
*For full description of station locations, see Table 17.
fx represents the mean for all samples, the range is given in parentheses, and n indicates
the total number of samples collected.
-------
TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
1. REPORT NO.
EPA-600/7-79-235
3. RECIPIENT'S ACCESSION NO.
4. TITLE AND SUBTITLE
ASSESSMENT OF ENERGY RESOURCE DEVELOPMENT IMPACT ON
WATER QUALITY: THE SAN JUAN RIVER BASIN
5. REPORT DATE
November 1979
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
Susan M. Melancon, Terry S. Michaud, and Robert W. Thoma
8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Environmental Monitoring and Support Laboratory,
U.S. Environmental Protection Agency
10. PROGRAM ELEMENT NO.
INE625, 81AEG
11. CONTRACT/GRANT NO.
12. SPONSORING AGENCY NAME AND ADDRESS
U.S. Environmental Protection Agency-Las Vegas, NV
Office of Research and Development
Environmental Monitoring and Support Laboratory
Las Vegas, NV 89114
13. TYPE OF REPORT AND PERIOD COVERED
Final to 1977
14. SPONSORING AGENCY CODE
EPA/600/07
15. SUPPLEMENTARY NOTES
16.ABSTRACT The San Juan River Basin is a key area in the search for untapped resources
to supplement our rapidly increasing energy requirements. Energy resource development
in the basin will provide a boost to the economy and employment sectors of this area.
However, development of these energy resources, combined with numerous irrigation
projects, is expected to have considerable impact on water resources in the San Juan
River Basin. It appears unlikely that there are sufficient surface or ground water
supplies to continue to meet projected needs in the area, and stretches of the San Juan
River are likely to become dry during low water years after all authorized diversions
are active. Decreased flows will accompany increased salt and sediment loadings from
energy developments. The result will be lower water quality, reducing water usability
for municipal, industrial, and irrigation purposes and having adverse impacts on the
aquatic ecosystem. A recommitment of water, presently allocated to other users, will
probably be necessary to assure maintenance of minimum flow in the river and to
preserve the regional aquatic and terrestial habitats. The existing network of U.S.
Geological Survey, Colorado State Health Department, and other State agencies' water
quality sampling stations is adequate and in order to assess the impact of energy
development should be carefully monitored on a regular basis in the future. Priority
listings of parameters to be measured to detect changes in water quality parameters as
a result of energy resource development and to assess future projects are recommended.
17.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.lDENTIFIERS/OPEN ENDED TERMS
c. COSATI Field/Group
Coal
Strip mining
Water resources
Water pollution
Pollutants
Electric power generation
Monitoring 17B
San Juan River Basin
08H
11
13B
13H
14A
21D
18. DISTRIBUTION STATEMENT
RELEASE TO PUBLIC
19. SECURITY CLASS (ThisReport)
UNCLASSIFIED
21. NO. OF PAGES
160
2O. SECURITY CLASS (This page)
UNCLASSIFIED
22. PRICE
EPA Form 2220-1 (Rev. 4-77) PREVIOUS EDITION is OBSOLETE
*US. GOVERNMENT PRINTING OFFICE: 1979— 683-282/2221
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