£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.

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                                                       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).

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               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

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                            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

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                           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

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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

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                  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).

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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

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                  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
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      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

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       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

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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

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   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.

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    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

-------

    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.

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    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

-------
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

-------
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

-------
    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

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                                            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).
                                       51

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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

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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

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             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

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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

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                                                                                       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.

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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

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                              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.

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ro
                                 1C  0  ID 20  3O Kilometers
        Figure 9.  Location  of U.S.  Geological Survey sampling stations  in  the  San Juan River Basin.

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            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.

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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,

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   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

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                               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

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        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
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    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

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                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)

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            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  .).

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       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)

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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

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    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

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     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

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  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

-------
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
                                     86

-------
  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.

                                      87

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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
                                      89

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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

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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.
                                     105

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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

                                      106

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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.
                                     107

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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
                                     108

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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.
                                     114

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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.
                                      115

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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

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        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.

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                                        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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-------
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                                       126

-------
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     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.

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                 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.

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                   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.

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              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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