svEPA
United States
Environmental Protection
Agency
Environmental Research
Laboratory
Duluth MN 55804
Research and Development
Environmental
Effects of Oil
Shale Mining and
Processing
Part III
The Water Quality of
Piceance Creek,
Colorado, Prior to Oil
Shale Processing
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RESEARCH REPORTING SERIES
Research reports of the Office of Research and Deve!opment. U.S. Environmental
Protection Agency, have been grouped into nine series These nine broad cate-
gories were established to facilitate further development and application of en-
vironmental technology Elimination of traditional grouping was consciously
planned to foster technology transfer and a maximum interface m 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 ECOLOGICAL RESEARCH series. This series
describes research on the effects of pollution on humans plant and animal spe-
cies, and materials. Problems are assessed for their long- and short-term influ-
ences. Investigations include formation, transport, and pathway studies to deter-
mine the fate of pollutants and their effects. This work provides the technical basis
for setting standards to minimize undesirable changes in living organisms in the
aquatic, terrestrial, and atmospheric environments
This document is available to the public through the National Technical.Informa-
tion Service. Springfield. Virginia 22161
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EPA-600/3-79-055
May 1979
ENVIRONMENTAL EFFECTS OF OIL SHALE MINING AND PROCESSING
PART III - THE WATER QUALITY OF PICEANCE CREEK, COLORADO,
PRIOR TO OIL SHALE PROCESSING
by
R. K. Skogerboe, C. S. Lavallee,
M. M. Miller, and D. L. Dick
Department of Chemistry
Colorado State University
Fort Collins, Colorado 80523
Grant No. R303950
Project Officer
Donald I. Mount
Environmental Research Laboratory - Duluth
Duluth, Minnesota 55804
ENVIRONMENTAL RESEARCH LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
DULUTH, MINNESOTA 55804
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DISCLAIMER
This report has been reviewed by the Environmental Research Laboratory,
U.S. Environmental Protection Agency, and approved for publication. Approval
does not signify that the contents necessarily reflect the views and policies
of the U.S. Environmental Protection Agency, nor does mention of trade names
or commercial products constitute endorsement or recommendation for use.
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FOREWORD
This report describes the water quality of Piceance Creek, Colorado.
Some of the first developments of the oil shale resource are anticipated in
this area. The results should be useful as mining activity begins, to assess
any changes in water quality as a result of mining activity.
Other reports in this series contain results of biological surveys.
Donald I. Mount, Ph.D.
Director
Environmental Research Laboratory-Duluth
m
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ABSTRACT
Water quality data have been collected at seven sites along Piceance
Creek and at one site each along Stewart, Black Sulphur, and Yellow Creeks
in the Piceance Basin, Colorado, during 1975-1977. Piceance, Stewart, and
Yellow Creeks may be perturbed by oil shale industry activities on the two
tracts, C-a and C-b, currently under development. The preoperational water
quality is generally poor due to higher levels of dissolved solids (contrib-
uted to by calcium, magnesium, sodium, bicarbonate, sulfate, chloride, and
potassium), manganese, and both dissolved and suspended iron. The quality
of water along Piceance Creek also declined at sites farther downstream
primarily due to influxes from groundwater aquifers in contact with soluble
mineral beds. The highest concentrations of the most common ions were
observed in June-August due to the combined effects of irrigation,
evapotranspiration, and minimal surface runoff contributions.
The concentrations of aluminum, cadmium, chromium, lead, and boron were
below the detection limits of the analysis method used. These were typically
below the permissible levels set for aquatic life by factors of 5-10. The
levels of copper, zinc, arsenic, selenium, and mercury were usually measurable
but still below permissible levels. The levels of copper, zinc, and mercury
were similar at all sites along Piceance Creek. The levels of arsenic,
suspended iron, and manganese were highest at the downstream limit of
sampling; the level of selenium showed the opposite trend.
Equilibrium calculations indicate that the natural conditions along
Piceance Creek—in particular the alkaline pH range (7.5-8.5) and high
carbonate alkalinity (300-800 mg CaC03/liter)--should limit the solubilities
of most metals to levels below the criteria standards set in protection of
aquatic life.
IV
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CONTENTS
Page
Foreword iii
Abstract iv
Figures vi
Tables viii
Acknowledgments ix
I Introduction 1
II Conclusions 3
III Recommendations 5
IV Description of the Study Area 6
Physical Description 6
Geology 6
Hydrology 6
V Description of the Monitoring Stations 13
VI Methods and Procedures 16
VII Results and Discussion 17
Gross Parameters and Common Ions 17
Heavy Metals 20
VIII Evaluation of Chemical Equilibria 37
References 46
Appendix A. Evaluation of Heavy Metal Equilibria 48
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FIGURES
Number Pa9e
1 Location of the Piceance Basin and prototype oil shale
Lease Tracts C-a and C-b 2
2 Generalized columnar section of the Piceance Basin
including location of aquifers 7
3 Geohydrologic section through the Piceance Creek Basin
showing the relation of the aquifers to the Green River
and Uinta Formation 9
4 Location map of the water quality monitoring stations
and drainage basin boundary of the study area 14
5 Plot of minimum, maximum, and average dissolved solids
measured at each site along Piceance Creek 18
6 Spatial and temporal distribution of dissolved solids
concentration 21
7 Spatial and temporal distribution of total solids
concentration 22
8 Spatial and temporal distribution of alkalinity 23
9 Spatial and temporal distribution of hardness 24
10 Spatial and temporal distribution of specific conductivity ... 25
11 Spatial and temporal distribution of calcium concentration ... 26
12 Spatial and temporal distribution of chloride concentration ... 27
13 Spatial and temporal distribution of magnesium concentration . . 28
14 Spatial and temporal distribution of potassium concentration . . 29
15 Spatial and temporal distribution of sodium concentration .... 30
16 Spatial and temporal distribution of sulfate concentration ... 31
VI
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Number Page
17 Range of measured concentrations, frequency of occurrence
above detection limits, and average concentrations above
and below Tract C-b 34
18 Spatial and temporal distribution of selenium concentration ... 35
19 Spatial and temporal distribution of arsenic concentration ... 36
20 Solubilities of Al, Cd, and Cu under conditions typical of
Piceance Creek 38
21 Solubilities of Fe and Hg under conditions typical of
Piceance Creek 39
22 Solubilities of Mn, Pb, and Zn under conditions typical
of Piceance Creek 40
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TABLES
Number Page
1 Average concentrations (in meq/liter) of chemical
constituents in groundwater aquifers associated
with Tract C-b 10
2 Trace element analyses (in yg/liter) from water wells
in the Piceance Drainage Basin 11
3 Description of the water quality sampling stations 15
4 Frequency with which trace constituent levels were above
USPHS limits for safe drinking water 32
5 Calculated and observed maximum concentrations (ug/liter)
along Piceance Creek compared with USPHS limits and U.S.
EPA criteria for freshwater aquatic life 41
6 Selected water quality criteria 43
7 Summary of results of equilibrium calculations: Controlling
precipitate and primary chemical forms of soluble metals .... 44
VTM
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ACKNOWLEDGMENTS
The field studies reported herein were carried out with the full
cooperation of Ashland Oil, Inc., Atlantic Richfield Co., The Oil Shale
Corp., and Shell Oil Co. This cooperation is greatly appreciated.
We thank L. J. Gray for collection of the water samples.
This research was funded by the U.S. Environmental Protection Agency,
Environmental Research Laboratory - Duluth, Research Grant No. R803950,
awarded to Natural Resource Ecology Laboratory, Colorado State University,
and Fisheries Bioassay Laboratory, Montana State University.
IX
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SECTION I
INTRODUCTION
Concern has been raised over the possible environmental impacts of oil
shale resource development in western Colorado. As part of a Federal
prototype leasing program, the oil shale development rights to two tracts in
Colorado have been acquired by several oil companies. As shown in Figure 1,
these tracts, designated as C-a and C-b, are located in the northwestern
part of the state, south and west of Meeker, Colorado. The focus in this
report is on Piceance Creek, which is the major surface drainage of the area
containing Tract C-b. Piceance Creek originates a few kilometers north of
the town of Rio Blanco and flows west and north to the White River. Tract
C-b is located immediately to the south of Piceance Creek, approximately 21
km northwest of Rio Blanco, between Stewart and Willow Creeks. The purpose
of this study has been to establish the preoperational water chemistry
characteristics along Piceance Creek before it is perturbed by mining
activity. Results of studies on the identification and distribution of
aquatic macroinvertebrates (Gray and Ward, 1978) and fishes (Goettl and Edde,
1978) in Piceance Creek have been reported separately. This report describes
the chemical conditions found along Piceance Creek above, adjacent to, and
below the C-b Lease Site.
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D Study
Area .Denver
Colorado
N
-*-^
Drainage^ ('Basin Boundary
15 Miles
10 15 Kilometers
Rifle
Figure 1. Location of the Piceance Basin and prototype oil shale Lease
Tracts C-a and C-b (USGS State Base Map, Weeks ejt aj_., 1974)
(—•—Piceance Creek drainage basin boundary, A monitoring
stations described in this report).
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SECTION II
CONCLUSIONS
1. Water quality data have been collected at seven sites along Piceance
Creek and at one site each on Stewart and Black Sulphur Creeks near
their confluences with Piceance Creek, and on Yellow Creek near its
confluence with the White River. These data are indicative of pre-
operational water quality conditions in the Piceance drainage basin.
2. Along Piceance Creek, significant increases in dissolved solids primarily
due to increases in magnesium, sodium, bicarbonate, and sulfate occur
at successive downstream sites. These increases are indicative of
fairly large influxes of poor quality groundwaters into the stream.
3. The spatial and temporal distribution curves for the common ions all
show a common pattern. The highest concentrations are observed at the
farthest downstream site in the summer season (June-August) due to the
combined effects of irrigation, evapotranspiration, and subsurface
inflow contributions.
4. The level of dissolved solids is above the permissible level of 500
mg/liter (U.S. Public Health Service, 1962) at all sites adjacent to or
below Tract C-b.
5. The levels of trace elements tend to be low at all sites during all
seasons. The levels of aluminum, cadmium, chromium, lead, and boron
were all below the detection limits, which are below the permissible
levels set for aquatic life by factors of 10-20 (U.S. Environmental
Protection Agency, 1977). The levels of copper, zinc, arsenic, selenium,
and mercury were usually detectable but still below the safe drinking
water levels. Levels above the limits set by the U.S. Public Health
Service (1962) at sites both above and below Tract C-b were observed
for manganese (10% frequency), dissolved iron (5% frequency), suspended
iron (47% frequency), and total iron (52% frequency).
6. Along Piceance Creek, the levels of suspended iron, arsenic, and
manganese are higher at the downstream limit of sampling than at the
upstream limit of sampling. These increases can be explained on the
basis of the larger quantities of these elements in the groundwater
aquifers, which contribute more water to the stream at lower elevations.
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7. The level of selenium is higher at the upper limit of the stream than
at the lower. This is unexpected since larger quantities of selenium
are found in the groundwater aquifers than in the alluvial aquifer.
This suggests that selenium may be removed from the stream by a physical,
chemical, or biological process that is inoperative for any of the
other trace elements analyzed.
8. Equilibrium calculations, using the common precipitating anions to
define representative conditions, indicate that the levels of the trace
metals may be increased; but that except for manganese, their concentra-
tions should remain below the USPHS permissible levels. The naturally
occurring pH along Piceance Creek (7.5-8.5) is in fact near the optimum
level for maintaining low levels of many metal ions through precipita-
tion control. Since the waters, due to the high levels of bicarbonate
ion, also have significant buffer capacities for both acid and base,
these conditions are likely to persist in the face of perturbations by
the development of the oil shale industry unless such perturbations
involve major influxes of acid or base material and/or metal complexing
agents.
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SECTION III
RECOMMENDATIONS
The present data indicate the water quality characteristics of Piceance
Creek prior to the initiation of oil shale development. They are also
indicative of the existence of sites where groundwater breakthrough to the
surface is more prominent. It is recommended that these data be considered
as preoperational references and that monitoring of Piceance Creek be
continued as oil shale development evolves. It is also recommended that
this monitoring program focus on the springs associated with the C-b tract
along Stewart and Willow Creeks, as well as the fault breakthrough near
Black Sulfur Creek, as those points are most likely to reflect early impacts
on water quality because of the adoption of the in situ and/or modified
in situ retorting technology.
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SECTION IV
DESCRIPTION OF THE STUDY AREA
PHYSICAL DESCRIPTION
The Piceance Creek Basin is characterized by north to northeast trending
ridges and valleys (Gray and Ward, 1978). Elevations near the Lease tracts
range from 2000 to 2350 m with local reliefs of 60 to 180 m. The basin is
classified as semiarid since total annual precipitation is only 30 to 46 cm.
The natural vegetation of the area is typical of the Great Basin desert.
Big sagebrush is dominant in valleys and on slopes, while pinyon-juniper
woodland dominates on ridge tops. Hay is grown on irrigated land in the
stream valleys and some shrubland has been cleared (chained) to promote
grassland for grazing.
GEOLOGY
As described by Weeks e_t al_. (1974), this area has been the site of
considerable sediment deposition from a huge lake which covered much of
northwestern Colorado during the Eocene epoch. In some areas, clay and
finely grained sediment deposits were 1067 m thick. Organic-rich layers
derived from plant and animal life were also deposited and then covered by
newer sand, silt, and clay sediments which eventually filled the lake. The
weight of these newer sediments consolidated the earlier mineral deposits
into sandstone, shale, and marl stone and the organic-rich material into the
solid hydrocarbon called kerogen. It is the marlstone, rich in kerogen,
that is commonly called oil shale. The resulting strata are shown in
Figure 2; these are representative of the strata of Tract C-b.
The oil shale strata are now classified as part of the Parachute Creek
Member of the Green River Formation. Of greatest commercial interest is the
Mahogany zone which ranges in thickness from 30 to 61 m and lies near the
upper extreme of this member. It is overlain by about 150 m of marlstone of
the Parachute Creek Member and 0 to 365 m of sandstone, siltstone, and
marlstone that are part of the Uinta formation. At Tract C-b, the Mahogany
zone is about 275 m below the surface (Donnel, 1961).
HYDROLOGY
Snowmelt in March or April produces the highest streamflow and recharges
the alluvium. Most rainfall is lost by evapotranspiration except during
intense and usually localized thunderstorms; hence by July, streamflow is
6
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Figure 2. Generalized columnar section of the Piceance Basin including
location of aquifers (Donne!, 1961).
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due almost entirely to groundwater discharge. Stream-flow characteristics
are also altered and variable between mid-March and early November due to
irrigation diversions. The amount of water diverted depends on weather,
crop types, and season.
The groundwater conditions associated with the Piceance Creek drainage
area have been thoroughly characterized, with respect to both hydrologic and
chemical parameters, by Weeks ejt aJL (1974). Their results will be summarized
here for the convenience of the reader. Piceance Creek is underlain by
three aquifers: an alluvial aquifer confined largely to valley bottoms
along creeks, and two groundwater aquifers separated by the Mahogany zone.
Recharge of the groundwater aquifers occurs most effectively at altitudes
above 2100 m where the snowpack thaws slowly enough to infiltrate, increase
soil moisture content to capacity, and thence percolate into the saturated
zone. Faults may be the most effective pathway for transfer of water from
the upper to the lower aquifer (Weeks ejt aj_., 1974). Both the upper and
lower aquifers contribute to stream recharge; contributions from the lower
aquifer are most significant along the lower portions of the stream.
Figure 3 is a diagram of a geohydrologic section through the drainage basin
(Weeks et^ al_., 1974); it shows how the variations in altitude within the
basin direct water flow from both aquifers toward the low point--i.e.,
Piceance Creek.
The general water quality characters of all three aquifers are sum-
marized in Table 1. These data demonstrate that the water quality of the
alluvial and upper aquifers is comparable but that the water quality of the
lower aquifer is significantly lower. The levels of several constituents in
the lower aquifer are much higher: dissolved solids concentrations in the
upper aquifer range from 500-2000 mg/liter while those in the lower aquifer
vary from 1000 to 30,000 mg/liter (Weeks et al_., 1974). Large deposits of
nahcolite (sodium bicarbonate) and halite^Tsodium chloride) underlie much of
Piceance Creek and are largely responsible for the high levels of alkalinity,
sodium, and chloride in the various aquifers.
The aquifers have also been analyzed for trace elements (Weeks and
Welder, 1964). The results summarized in Table 2 indicate that the concen-
trations of most trace constituents are significantly higher in the lower
aquifer. The lower aquifer is found to have measurable levels of aluminum,
arsenic, barium, boron, iron, lead, lithium, manganese, molybdenum, selenium,
and strontium. In particular, the levels of boron, barium, and lithium are
frequently observed at levels above those set by USPHS (1962) (barium = 1000
yg/liter) or above levels cited by Hem (1970) as toxic to plants (boron,
3000 yg/liter and lithium 5000 yg/liter).
The presence of several aquifers, irrigation diversions, and high
evapotranspiration demands results in a complicated water budget for the
area. This may be complicated further by two factors. First, the oil shale
industry may require significant amounts of water. Second, the Mahogany
zone, which currently separates the two groundwater aquifers, will be
altered and/or removed (perhaps drastically). These perturbations may
therefore affect both hydrologic and water quality parameters of the Piceance
Creek drainage area. The complicated nature of flow patterns (Figure 3)
8
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27001
2400-
2100-
1800-
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TABLE 1. AVERAGE CONCENTRATIONS (IN MEQ/LITER) OF CHEMICAL
CONSTITUENTS IN GROUNDWATER AQUIFERS ASSOCIATED WITH
TRACT C-b (WEEKS ET AL. 1974)
Water
quality
parameter
Alluvial
aquifer
Upper
aquifer
Lower
aquifer
K
Na
Ca
HC03
Cl
S04
F
Mg
0.08
20.00
4.00
7.00
20.00
1.00
10.00
1.80
0.04
8.00
3.00
5.00
9.00
0.50
7.00
0.08
0.3
175.0
0.3
0.8
150.0
20.0
1.9
1.8
10
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TABLE 2. TRACE ELEMENT ANALYSES (IN yG/LITER) FROM WATER
WELLS IN THE PICEANCE DRAINAGE BASIN
(WEEKS AND WELDER, 1964; WEEKS ET AL., 1974)
Element
Aluminum
Arsenic
Boron
Dissolved iron
Lead
Manganese
Selenium
Upper aquifer
Tract C-b Tract C-a
--§/
3 2
5,600
190
<50
10
5
Lower
Tract C-b
0
70
250,000
3,300
--
200
40
aquifer
Tract C-a
0
17
5,500
—
300
30
--
— Dashed lines indicate no data available.
11
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makes the prediction of mining activity impact difficult. It is therefore
particularly important to characterize the premining water quality conditions
so that perturbations due to the oil shale related activities can be rapidly
identified if and/or when they occur. This report summarizes these
conditions.
12
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SECTION V
DESCRIPTION OF THE MONITORING STATIONS
The locations of the monitor sites of the present study are shown in
Figure 4 and described in more detail in Table 3. Stations PO and PI are
located upstream of Tract C-b and thus serve as reference points. Stations
P2-P4 are located on sites which reflect inflow from streams (Stewart and
Willow Creeks) and aquifers draining the C-b area. Site SI on Stewart Creek
is indicative of its possible impacts on Piceance Creek. Sites P6 and P7
are located about 10 miles farther downstream near the confluence with the
White River. The section of the creek between P4 and P6 is recipient of
increasingly larger groundwater inflows from springs. Moreover, Weeks et; al.
(1974) believed that the lower aquifer discharges directly into the alluvial
aquifer near site P7 so that water quality changes occurring between P6 and
P7 should reflect this. Site P5 is located on Black Sulphur Creek just
prior to its confluence with Piceance Creek; the analysis reflects only the
characteristics of the former but is indicative of its possible impact on
the latter. Finally, the Yl station reflects the overall characteristics of
the inflow from the Tract C-a watershed. The locations of these stations
coincide with those of the macroinvertebrate study (Gray and Ward, 1978) and
are such that an overview of the preoperational water quality characteristics
and inflow contributions can be obtained.
13
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N
Kilometers
0
till
o
5
i |
'P
1
1
5
Miles
15
i
i
1C
(—iStudy
I—' Arpn
• Denver
Colorado
\
Figure 4. Location map of the water quality monitoring stations and
drainage basin boundary of the study area (see Table 3 for
description).
14
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TABLE 3. DESCRIPTION OF THE WATER QUALITY SAMPLING STATIONS-7
Station number
S_ -— 0>
8 .£?£ Elevation Site description
PO 2103 n
(6900 ft)
PI 1937 m
(6520 ft)
SI 1999 m
(6560 ft)
P2 1975 m
(6480 ft)
E p3 1963 m
S (6440 ft)
1 P4 1902 m
"° (6240 ft)
P5 1902 m
(6240 ft)
P6 1793 m
(5900 ft)
P7 1749 m
(5740 ft)
Yl 1689 m
(5540 ft)
Piceance Creek about S.O km
downstream from Rio Bianco
Piceance Creek, 2.5 km up-
stream from confluence with
Stewart Creek
Stewart Creek 50 m above
confluence from Piceance
Creek
Piceance Creek about 300 m
downstream from confluence
with Stewart Creek
Piceance Creek 4.1 km up-
stream from confluence with
Wil low Creek
Piceance Creek about 100 m
downstream from confluence
with Wil low Creek
Black Sulphur Creek 2.6 km
upstream from confluence with
Piceance Creek
Piceance Creek 1.0 km upstream
from confluence with Dry Fork
Piceance Creek 2.5 km upstream
from confluence with White
River
Yellow Creek 1.5 km upstream
from confluence with White
River and SO m uostream from
USGS gauging station
-Collections at all sites were carried out monthly from October 1975
through "arch 1977.
15
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SECTION VI
METHODS AND PROCEDURES
Water samples were collected at each sampling station on a monthly
basis. These were preserved according to the recommended procedures des-
cribed in the EPA manual on water analysis and analyzed by the standard
procedures given therein (U.S. Environmental Protection Agency, 1974). The
data obtained were keypunched and placed on permanent tape file in the
university computer system so that they could be summarized and evaluated
via any of several available procedures, and are available in a summary
compilation (Skogerboe ejt al_., 1978).
An analytical quality assurance program was maintained throughout the
term of this project. This included: (1) submission of the same samples to
the analytical lab under different numerical designations to obtain precision
estimates; (2) running reference water samples from the U.S.G.S. (using a
designation system which disguised the fact that they were reference samples)
to obtain accuracy estimates and; (3) cross checking analyses by using
spike-recovery methods. Approximately 3-4% of all samples analyzed were
actually check samples of the above types. The overall conclusions drawn
from these quality assurance checks was that the analyses are typically
accurate to ±10% of the stated value; certain types of measurements, e.g.,
pH and specific conductivity were found to be accurate to better than ±5%.
16
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SECTION VII
RESULTS AND DISCUSSION
Sampling was carried out at the sites described above from October 1975
through March 1977. The results of the water quality analyses are summarized
for all parameters on a monthly basis in a summary compilation available upon
request at cost of reproduction (Skogerboe et_ aT_., 1978). An overview
evaluation of these data is presented in general terms below for the conve-
venience of the reader. The following discussion is segmented into
consideration of the most commonly measured parameters and the trace metals.
GROSS PARAMETERS AND COMMON IONS
In developing an overview of the present water quality characteristics
of the area and the impacts of inflow from associated streams and aquifers,
it is expedient to consider the dissolved solids data in relation to the
monitor network as a general indication of similarities and differences.
Figure 5 presents a summary of the maximum, minimum, and average dissolved
solids concentrations along Piceance Creek. Notable features of these data
include the following:
1. The dissolved solids concentrations consistently exceed 500 mg/liter at
all sites below PO.
2. The differences between levels at PO and PI generally reflect the
effects of both aquifer inflow and irrigation return flow in that
segment of the stream.
3. Changes observed between PI and P2 and P3 and P4 reflect the inflows
from Stewart and Willow Creeks, respectively. The water quality charac-
teristics of Stewart Creek are very comparable to those observed at P2
and P3. In addition, there are relatively minor changes in the levels
of the parameters between P2 and P4. Thus, the inflows of Stewart and
Willow Creeks have relatively minor effects on the water quality
parameters along this section of the stream. In view of this, averages
of the parameter concentration levels for sites P2-P4 may be used in
the generalized overview analysis.
4. Differences between P4 and P6 partially reflect the input of Black
Sulphur Creek which has generally higher levels of most constituents
than those observed at P4. This may be due to upwelling from the lower
aquifer through the fault associated with Black Sulphur Creek (Figure 3).
17
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en
a
2400
2000
1COO
o 120°
BOO
400
P6
P7
Figure 5. Plot of minimum, maximum, and average dissolved solids measured at
each site along Piceance Creek. (Permissible level from U.S.
Public Health Service, 1962.)
18
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5. The concentration increases between P6 and P7 reflect the discharge of
water from the lower aquifer (Figure 3) into the stream (Weeks et al.,
1974).
In essence, evaluation of the results based on these general features
provides general indications of the contributions to streamflow (and their
concomitant effects on the water quality parameters) by groundwater and
irrigation return flows.
Consideration of streamflow, climatological data, and local agricultural
practices has also been used to choose the following seasonal groupings on a
general basis.
1. The months of September-November represent a dry period with below
freezing nights. Although irrigation along the creek is often continued
into November, losses by evapotranspiration are generally low.
2. During December-February the streamflow is at a minimum and no irrigation
is carried out. Most snowfall occurs during this period, but runoff
due to snowmelt is at a minimum.
3. March-May are the months of maximum snowmelt runoff at the elevations
associated with the Lease sites. Snowmelt from higher elevations
upstream may extend into June. Irrigation is often resumed by April.
4. Evapotranspiration demands and irrigation requirements are generally
the greatest during June-August. Streamflow gradually decreases during
this period as snowmelt at higher elevations is completed.
These seasonal time groupings have been used in the present overview
analysis as a further means of differentiating between average effects
associated with the different sources of water quality impacts.
Finally, it should be noted that the data for the sites not directly on
Piceance Creek, i.e., SI, P5, and Yl, agree well with results reported by
the U.S. Geological Survey (Weeks et al_., 1974; Weeks and Welder, 1964) as
do the on-stream results. The concentration levels of the off-Piceance
sites are consistent with their elevations and their locations relative to
the characteristics of the contributing aquifers and associated mineral
deposits. Although the data for these three sites (SI, P5, and Yl) are not
specifically discussed below, the results for SI and Yl (Skogerboe et_ al_.,
1978) will serve as preoperational references for Stewart and Yellow Creeks,
respectively. Stewart Creek will likely be perturbed by oil shale develop-
ment activities at Tract C-b while Yellow Creek may be affected by activities
on Tract C-a. Further, it is possible that Black Sulphur Creek (P5) may not
receive waters associated with either Lease tract. Due to the topography of
the region, the aquifers contributing to this creek do not appear to be
directly involved with the shale development sites. As a result, it is
possible that the present data could be used in combination with future data
to estimate the natural variations in water quality characteristics in the
western portions of the watershed and thereby serve as a comparative reference
for variations occurring on streams more likely to be impacted.
19
-------
On the basis of the above discussion, the average concentrations of the
common water quality parameters have been determined and summarized in
spatial and temporal plots to provide a general overview. Consideration of
Figure 6, which summarizes the dissolved solids results, indicates the
following:
1. Upstream of P6, the dissolved solids concentrations are relatively
constant within a season at each individual site. The increasing trend
from PO to P4 is small compared to increases below P4. The similarities
in these trends from season-to-season imply that irrigation return flow
does not have a major impact (compare June-August with December-
February).
2. Below P4, the inflow of ground waters through springs results in sharper
increases in dissolved solids and greater variations in seasonal fluctu-
ations. The occurrence of a maximum level of dissolved solids during
the June-August period reflects increases in the relative contributions
of subsurface waters to streamflow coupled with higher evapotranspiration
demands and increased irrigation return flow. The combined effects of
these may be approximated by comparison with the December-February
period during which all three contributing factors are at minima.
The general trends observed for dissolved solids recur for most of the
common water quality parameters. Examination of the graphs of these
(Figures 7-16) leads to a general conclusion. The dissolved solids increases
are due primarily to increases in the levels of sodium, bicarbonate, magne-
sium, sulfate, and (to a lesser extent) chloride. On the other hand, the
level of calcium is lower at P7 than at upstream sites. These changes,
which are generally most prominent between P6 and P7, reflect in particular
the inflow of lower quality water from the lower aquifer (Table 1 and
Figure 3). They may also reflect the removal of dissolved calcium by precipi-
tation as the carbonate of the stream increases (compare Figures 8 and 11).
Finally, the data suggest the predominance of equilibria associated with
certain types of minerals, e.g., nahcolite (NaHC03), halite (NaCl), epsomite
(MgSOj, and gypsum (CaSOJ (Weeks et §1., 1974). The fact that the pH of
the stream is quite constant on both temporal and spatial bases testifies to
the general predominance of a pH-controlling set of equilibria related to
the general mineralization of the region. These common characteristics must
also directly or indirectly influence the concentrations of trace metals.
HEAVY METALS
The levels of most trace elements were low at all sites during all
seasons. The levels of aluminum, cadmium, chromium, lead, and boron were
all below the detection limits, which are generally below the permissible
levels for aquatic life [(U.S. Environmental Protection Agency, 1977) see
Table 6] by factors of 10-20. The levels of copper, zinc, arsenic, selenium,
and mercury were usually detectable but still below the permissible levels
for aquatic life (U.S. Environmental Protection Agency, 1977). Levels above
these were observed only for suspended and dissolved iron and for manganese.
These data are summarized in Table 4. Data obtained for detectable elements
20
-------
1500 -1
S-
OJ
CD
E
if}
-a
-a
QJ
o
in
•r—
Q
1000 -
^1000
-500
Below
Tract C-b~ P2-4
Adjacent to%
Tract C-b
Above Tract
C-b
Jun.-Aug.
Mar.-May
Dec.-Feb.
Sept.-Nov.
Figure 6. Spatial and temporal distribution of dissolved solids
concentration.
21
-------
2000-1
1-2000
-1000
Below
Tract C-b
Adjacent to
Tract C-b
Jun,-Aug.
Mar.-May
Dec.-Feb.
Above
Tract C-b
Sept.-Nov.
Figure 7. Spatial and temporal distribution of total solids concentration.
22
-------
1000-1
s_
a."
•i- ro
r— O
500 -
Below
Tract C
Adjacent to
Tract C-b
1—1000
- 500
Jun.-Aug.
Mar.-May
ec.-Feb.
Above
Tract C-b
5ept.-Nov.
Figure 8. Spatial and temporal distribution of alkalinity.
23
-------
400-
4-
a>
4->
1/5 'I-
to i—
0; \
C 0
-o o
S- tJ
- 400
200-
- 200
Below
Tract C-
Adjacent to
Tract C-b
Jun.-Aug.
Mar.-May
Dec.-Feb.
Above
Tract C-b
Sept.-Nov.
Figure 9. Spatial and temporal distribution of hardness.
24
-------
r2ooo
-1000
Below ^\-
Tract C-b
Adjacent to
Tract C-b
Jun.-Aug.
Mar.-May
Dec.-Feb.
Abov
Tract
C-b
Sept.-Nov.
Figure 10. Spatial and temporal distribution of specific conductivity.
25
-------
1 v
3 ->
<° oi
0 E
P7
Below^
Tract C-b
Adjacent
to Tract C-b
Jun.-Aug.
Mar.-May
Dec.-Feb.
Above
Tract C-b
Sept.-Nov.
Figure 11. Spatial and temporal distribution of calcium concentration.
26
-------
s_
QJ
S-
o
Below
Tract C-b
Adjacent to
Tract C-b
Above
Tract C-b
r- 50
- 30
- 10
Jun.-Aug.
Mar.-May
Dec.-Feb.
Sept.-Nov.
Figure 12. Spatial and temporal distribution of chloride concentration.
27
-------
3
l/l -r-
O I—
Belov/
Tract C-b
Adjacent to
Tract C-b
Jun. -Aug.
Dec.-Feb.
Mar. -'lay
Above
Tract C-b
Sept.-Nov.
Figure 13. Spatial and temporal distribution of magnesium concentration.
28
-------
10 n
S-
Ol
5 -
l/l
(/>
(O
O
Q.
P7
Below k P6
Tract C-b ?2-$
Adjacent toS^_ pi
Tract C-b
Above
Tract C-b"
rlO
!- 5
Jun.-Auo.
•Jar. -May
Dec.-Feb.
PO "^ept.-Nov.
Figure 14. Spatial and temporal distribution of potassium concentration.
29
-------
30C~i
s_
ID
E
o
I/O
Below
Tract C-b
Adjacent to
Tract C-b
r-300
-100
Jun.-Aug.
Mar.-May
Dec.-Feb.
Above
Tract C-b
PO ^Sept.-Nov.
Figure 15. Spatial and temporal distribution of sodium concentration.
30
-------
6001
Tract C-b
Adjacent to
Tract C-b
r600
-400
-200
Jun. -Aug.
Mar.-May
Dec.-Feb.
Above
Tract
PO Sept.-Nov.
Figure 16. Spatial and temporal distribution of sulfate concentration.
31
-------
TABLE 4. FREQUENCY WITH WHICH TRACE CONSTITUENT LEVELS WERE
ABOVE USPHS LIMITS FOR SAFE DRINKING WATER
Constituent
Arsenic
Boron
Cadmi urn
Chromium
Copper
Iron (dissolved)
Iron (suspended)
Iron (total)
Lead
Manganese
Selenium
Zinc
USPHS limit
(yg/liter)a/
50
3000
10
50
1000
300
300
300
50
50
10
5000
Frequency observed
above USPHS limit
(*)
0
0
0
0
0
5.5
47.0
52.0
0
10.0
0
0
Number of times
de tec ta bleb/
60
38
110
100
110
110
125
107
110
110
60
109
-/U.S. Public Health Service (1962).
-Total sample analyses = 18 mo. x 10 samples/mo. = 180
32
-------
at sites PO (farthest upstream) and P7 (farthest downstream) are given in
Figure 17. The bars indicate the range of concentrations observed for each
element over the sampling period. If an element was not always detectable
(copper, dissolved iron, mercury, manganese, and zinc), the lower end of the
bar indicates the detection limit; for the other elements (selenium, arsenic,
and suspended iron) the lower end indicates the minimum observed value. An
average concentration was also computed; for elements in which some concen-
trations were below the detection limit, the detection limit was taken as an
estimate of the actual concentration present. As a result, the averages--
indicated by the -^- symbol on each bar--are upper limit estimates of
actual values. The percentage value given at the top of each bar indicates
the percentage of samples for which the element concentration was above the
indicated detection limit. This treatment results in a greater overestimation
of the average value when an element is detected fewer times; however,
approximate information may still be obtained from such an estimate.
The data in Figure 17 indicate that the concentrations of dissolved
iron, mercury, zinc, and copper remained about the same at the upper and
lower extremes of the stream. In contrast, the levels of suspended iron,
arsenic, and manganese show significant increases at the lower site. Selenium
shows the opposite trend; levels were higher at the upper extreme and
decreased significantly at the lower end of the stream. The increases in
iron, arsenic, and manganese can be explained by the large quantities of
these elements in the groundwater aquifers; these contribute more water to
the stream at lower elevations. However, the level of selenium was also
higher in the groundwater aquifers, but decreased at downstream sites. The
different behavior pattern for selenium is emphasized by its spatial and
temporal distribution curve (Figure 18) compared with those of either
arsenic (Figure 19), which, along with selenium, was always detectable, or
the common ions (Figures 11-16), which all follow a common pattern. In this
pattern, the highest levels were observed farthest downstream during the
June-August season. The level of selenium was usually lower at P7 than at
any upstream sites and was particularly low during the June-August season.
This suggests that selenium may be removed from the stream by some chemical
or biological process that is inoperative for any of the other trace elements
analyzed. Alternatively, its removal from solution by reaction with the
increased levels of suspended iron found at P7 may be responsible. Howard
(1972) has shown that the geochemical behavior of selenium in natural waters
is controlled by adsorption on hydrous ferric oxides. The equilibrium
conditions characteristic of such a removal process are present in Piceance
Creek.
33
-------
Se
loos
"9-
100%
PO P7
As
1005;
.*.
100?
4U -
30 -
20 -
in .
n
suspended
Cu Fe
h9"
IK
*
12000-
8000-
4000-
n-
100"
100:.
+
PO P7
PO P7
PO P7
dissolved
Fe
Hg
300-
200-
100-
bbt
^
43:;
*
0.06 •
0.04-
0.02-
7S:v 62;'
.-
*
450 £
60"
- 40'
20-
Mn
Zn
PO P7
PO P7
PO P7
uu •
60 -
40 -
20 -
n .
82 '„
79?-
-9-
PO P7
Figure 17. Range of measured concentrations, frequency of occurrence above
detection limits, and average concentrations above (PO) and
below (P7) Tract C-b. (When frequency of occurrence above
detection is less than 100%, the lower limit of bar indicates
detection limit; the upper limit of all bars indicates maximum
observed concentration; Vindicates average concentration
observed. Percentage value indicates frequency with which the
Concentration was above the detection limit.)
34
-------
Below
Tract C-b
Adjacent
to Tract C-b
Jun.-Aug.
Mar.-May
Dec.-Feb.
Above
Tract C-b
Sept.-Nov.
Figure 18. Spatial and temporal distribution of selenium concentration.
35
-------
Below
Tract C-b , P2-4
Adjacent
to Tract C-b
Jun.-Aug.
Dec.-Feb.
Mar.-May
Above
Tract C-b
Sept.-Nov.
Figure 19. Spatial and temporal distribution of arsenic concentration.
36
-------
SECTION VIII
EVALUATION OF CHEMICAL EQUILIBRIA
The low levels of the heavy metals are consistent with the expectation
that chemical factors play roles in controlling the soluble metal ion concen-
trations. The high levels of sulfate and alkalinity, coupled with the
relative constancy of pH, makes it quite likely that complexation and precipi-
tation equilibria involving sulfate, carbonate, and hydroxide may limit the
levels of several trace elements to low levels. The limiting concentrations
of several trace metals have therefore been calculated using the methods
described previously (Skogerboe et al_., 1979). This description has been
included as Appendix A. In brief, the average levels of alkalinity (bicar-
bonate), sulfate, chloride, and pH are taken as representative limiting
boundary conditions; the controlling precipitates are determined via solubil-
ity calculations; and the possible increases in solubility due to complexation
are estimated by calculation. This results in an estimate of the upper
limit value for total dissolved metal. Equilibrium calculations have not
been carried out for the non-metals, arsenic and selenium, because the
levels of these elements are believed to be controlled by other factors
(Hem, 1970; Howard, 1972).
Plots of the calculated maximum levels of dissolved metal versus pH
have been prepared for the average conditions observed at sites PO and P7 on
Piceance Creek. Streams such as this are exposed to oxygen from the atmos-
phere and are thus expected to exhibit oxidizing conditions. However, in
natural water systems, kinetic factors rather than oxygen availability may
be important in determining oxidation state and, since different redox
mechanisms may be operative for different elements, some metals may exist in
an oxidized form while others remain largely in a reduced form (Hem, 1970).
Therefore, for metals having more than one common oxidation state, each
state was considered separately.
The resulting data (Figures 20-22) show that the solubilities of most
metal ions are at minimum levels near the pH characteristic of Piceance
Creek. At lower pH values, protonation of anions (e.g., OH~ to H20, C032~ to
HCOs and H2C03) decreases the importance of precipitation and increases the
metal ion solubilities. At high pH values, the formation of soluble hydroxide
complexes usually increases metal ion solubilities. Hence the naturally
occurring pH along Piceance Creek (7.5-8.5) is at or near the optimum level
for maintaining low levels of metals in solution. In Table 5 the observed
maximum concentrations are compared with those calculated for the average
conditions observed at sites PO and P7. For mercury, zinc, copper, manganese,
and lead the actual observed levels were far below those calculated for the
2+ oxidation states of the metals (the most likely oxidation state present).
37
-------
Figure 20. Solubilities of Al, Cd, and Cu under conditions typical of
Piceance Creek. Conditions representative of upper Piceance
Creek [HC03] = 360, [SOJ = 125, [Cl] = 1, [POJ = 0.01 (in
mg/liter). — Conditions representative of lower Piceance Creek
[HC03] = 1080, [SOiJ = 450, [Cl] = 42, [POJ = 0.01 (in mg/liter).
The precipitating forms of the elements, which control the solu-
bility over the indicated ranges, are given on the figures.
38
-------
\
\
Figure 21. Solubilities of Fe and Hg under conditions typical of Piceance
Creek. Conditions representative of upper Piceance Creek
[HC03] = 360, [SOJ = 125, [Cl] = 1, [POJ = 0.01 (in mg/liter).
--- Conditions representative of lower Piceance Creek [HC03] =
1080, [SOJ = 450, [Cl] = 42, [POJ = 0.01 (in mg/liter). The
precipitating forms of the elements, which control the solubility
over the indicated ranges, are given on the figures.
39
-------
Figure 22. Solubilities of Mn, Pb, and Zn under conditions typical of
Piceance Creek. Conditions representative of upper Piceance
Creek [HC03] = 360, [SOJ = 125, [Cl] = 1, [POJ = 0.01 (in
mg/liter). — Conditions representative of lower Piceance Creek
[HC03] = 1080, [SOJ = 450, [Cl] = 42, [POJ = 0.01 (in mg/liter).
The precipitating forms of the elements, which control the
solubility over the indicated ranges, are given on the figures.
40
-------
TABLE 5. CALCULATED AND OBSERVED MAXIMUM CONCENTRATIONS (yG/LITER) ALONG
PICEAiMCE CREEK COMPARED WITH USPHS LIMITS AND U.S. EPA CRITERIA FOR FRESHWATER AQUATIC LIFE
Metal
Cd(II)
Hg(D
Hg(II)
Al(I-II)
Zn(II)
Cu(I)
Cu(II)
Fe(II)
Fe(III)
Mn(II)
Pb(II)
P0a/
Calculated
raaximuni?/
0.3
1.6
360,000
2.4
85.0
1.5
350.0
140.0
0.0001
2500.0
1.0
Observed,
maximum—
<5.0
0.5
<100.0
0.72
10.0
190.0
22.0
<0.2
P7b/
Calculated
maximumS.
0.1
0.6
360,000
1.6
28.0
5.2
480.0
50.0
0.0001
930.0
0.5
Observed
maximum^/
<5.0
0.14
<100.0
0.044
25.0
130.0
450.0
0.02
Drinking water
(USPHS, 1962)
10
..£/
—
5000
1000
1000
300
300
50
50
Aquatic life
(U.S. Environmental
Protection Agency,
1977)
0.4-12.0
0.05
--
0.01 x 96-h LC50
0.1 x 96-h LC50
1000
--
0.01 x 96-h LC50
— Upper limit of creek.
— Lower limit of creek.
-/Conditions: pH = 8.0; al k = 300 mg CaC03/liter; [SOJ = 125 mg/liter; [Cl] = 1 mg/liter;
[PO,,] = 0.01 mg/liter.
-/For metals with more than one common oxidation state, the observed level is for total
dissolved metal and does not distinguish between oxidation states.
-/Conditions: pH = 8.2; alk = 1080 mg CaC03/liter; [SOJ = 450 mg/liter; [Cl] = 42 mg/liter;
[P0,(] = 0.01 mg/liter.
-/Dashed lines indicate no limit given.
41
-------
This suggests that if future influxes of these metals occur, their levels
may increase beyond their present levels but they are less likely to exceed
the calculated levels unless unknown complexing agents are also present.
The concentration of iron is already above the level calculated assuming
either Fe(II) or Fe(III). This suggests that factors other than precipitation
and complexation may be operative. One explanation is that iron(III) hydrox-
ide may be present in a very finely divided particulate form that passes
through 0.45 micron filters, thus being measured as soluble iron. Another
explanation for the high observed iron levels is that complexation by organic
species may increase its solubility beyond that expected via purely inorganic
control.
For comparative purposes, a summary of the USPHS limits for safe drinking
water is also given in Table 5, and Table 6 shows EPA limits for aquatic
life and domestic water supplies (U.S. Environmental Protection Agency,
1977). These are far above the calculated and observed levels for all
metals except manganese. Thus, although increases in the concentrations of
metal ions may still occur, they may be limited to levels that are still
safe.
As indicated by the solubility curves for the metals (Figures 20-22),
metal ion solubilities are generally expected to be low under the conditions
characteristic of the downstream portion of Piceance Creek. For copper,
however, the solubility is expected to increase under downstream conditions.
The explanation for this is found in Table 7 which lists the major chemical
forms of the soluble metal. The values given in parentheses after each
metal complex are the percentages of the total metal present in this form in
the pH range 7.5-8.5. For copper(I), or copper(II), the major soluble forms
are CuCl° or CuOH2°, respectively, while the controlling precipitate is the
hydroxide. Thus the free copper concentration depends only on pH and is the
same for both sets of conditions, but the total copper solubility is increased
when more Cl" [for Cu(I)] or OH" [for Cu(II)] is present; downstream
conditions are characterized by larger concentrations of both of these ions.
Another salient feature apparent in Table 7 is the large role played by
pH in determining chemical forms. Most frequently, the metal ions exist
largely as either the aquated species or as a hydroxo species; the pH deter-
mines the ratio. Thus, small shifts in pH should significantly alter the
major form of these metal ions in solution. The highly alkaline nature of
stream conditions along Piceance Creek will serve to maintain the current pH
levels in the event of small perturbations. However, a major influx of
acidic or caustic material that exceeds the buffer capacity would greatly
alter not only the total solubility, but also the form of the soluble metal
ion.
42
-------
TABLE 6. SELECTED WATER QUALITY CRITERIA
(U.S. ENVIRONMENTAL PROTECTION AGENCY, 1977)
Parameter
Alkalinity
Arsenic
Cadmium
Chromium
Copper
Iron
Lead
Manganese
Mercury
Nickel
Dissolved oxygen
PH
Selenium
Si 1 ver
Freshwater aquatic life
> 20 mg/liter
--
0.4-4 yg/liter (soft water)-/
1.2-12 yg/liter (hard water)
100 yg/liter
0.1 x a 96-h LC50-/
1.0 mg/liter
0.01 x a 96-h LC50
--
0.05 yg/liter
0.01 x a 96-h LC50
5.0 mg/liter minimum
6.5 to 9.0
0.01 x a 96-h LC50
0.01 x a 96-h LC50
Drinking
water
--
50 yg/liter
10 yg/liter
50 yg/liter
1.0 mg/liter
0.3 mg/liter
50 yg/liter
50 yg/liter
2.0 yg/liter
--
--
5.0 to 9.0
10 yg/liter
50 yg/liter
CaC0
water: 0-75 mg/liter CaC03; hard water: 150-300 mg/liter
LC50 is defined as the concentration of a toxicant which is lethal
to 50% of the organisms tested under the test conditions in a
specified time. (The receiving or comparable water should be used
as the diluent for sensitive freshwater resident species.)
43
-------
TABLE 7. SUMMARY OF RESULTS OF EQUILIBRIUM
CALCULATIONS: CONTROLLING PRECIPITATE AND PRIMARY
CHEMICAL FORMS OF SOLUBLE METALS
Metal
ion
A13+
Cd2+
Cu+
Controlling
precipitate
A1(OH)3
CdC03
CuOH
Sol
Upstream ,
conditions-
A1(OH)2+ (100)-
Cd2(aq)(78-27)
CdOH+(21-72)
Cu(aq)<10>
uble forms
Downstream, ,
conditions—
-1 A1(OH)2+ (100)
Cd(aq)2+(78-27)
CdOH+(21-72)
Cu(aq)<2>
Cu2+ Cu(OH).
Fe2+
Fe3+
Pb2+
FeC0
Fe(OH)3
PbC03
CuCl°(90)
Cu(OH)2°(52-89)
CuC03°(37-6)
Cu(C03)22-(2-3)
Cu2|aq)(4-0.01)
CuCl°(97)
CuCl2" (1)
Cu(OH)2°(29-63)
CuC03°(56-12)
Cu(C03)22-(10-24)
Cu2|aq)(3-0)
CuSO.^O.^O)
Fe2|aq) (84-46)
FeOH+(9-51)
Fe(OH)3°(100)
Pb2|aq)(56-15)
FeOH+(7-44)
FeS04°(10-6)
Fe(OH)3°(100)
Pb2(aq)(67-23)
PbOH+(30-78) PbOH+(20-69)
Pb(OH)2°(0.1-3) Pb(OH)2°(0-2)
PbCl+(1.5-0.5)
44
-------
TABLE 7. Continued.
Soluble forms
Metal Controlling
ion precipitate
Upstream ,
conditions-
Downstream, ,
conditions—
Hg2
2+
MnCO:
Hg2C03
Hg2+ Hg(OH)2
Zn2+ ZnC03
MnHC03"(15)
Hg2OH+(98-100)
Hg2S04°(l)
Hg(OH)2°(100)
Zn2|aq)(92-76)
ZnOH+(2-19)
ZnSO^S-B)
MnHC03"(25)
Hg2OH+(98-100)
Hg(OH)2°(100)
Zn2|aq) (88-76)
ZnOH+(l-15)
-Upstream conditions: alk = 300 mg CaC03/liter, [SO^] =
125 mg/liter, [Cl] = 7 mg/liter, [POJ = 0.01 mg/liter.
-Downstream conditions: alk = 850 mg CaC03/liter, [SOJ =
450 mg/liter, [Cl] = 42 mg/liter, [PO^] = 0.01 mg/liter.
— The values in parentheses are the predicted percentages
present in these forms in the pH range 7.5-8.5.
45
-------
REFERENCES
Donnel, J. R. 1961. Tertiary geology and oil-shale resources of the
Piceance Creek basin between the Colorado and White Rivers, north-
western Colorado. U.S. Geol. Surv. Bull. No. 1082-L. Washington, D.C.
Goettl, J. P., and J. W. Edde. 1978. Environmental effects of oil shale
mining and processing. Part I - Fishes of Piceance Creek, Colorado,
prior to oil shale processing. Ecol. Res. Ser. Rep. EPA-600/3-78-096,
U.S. Environmental Protection Agency, Duluth, MN 18 p.
Gray, L. J., and J. V. Ward. 1978. Environmental effects of oil shale
mining and processing. Part II - The aquatic macroinvertebrates of the
Piceance Basin, Colorado, prior to oil shale processing. Ecol. Res.
Ser. Rep. EPA-600/3-78-097, U.S. Environmental Protection Agency,
Duluth, MN. 39 p.
Hem, J. D. 1970. Study and interpretation of the chemical characteristics
of natural water. U.S. Geol. Surv. Water Supply Paper 1473. Washington,
D.C. p. 207-208.
Howard, J. H., III. 1972. Control of geochemical behavior of selenium in
natural waters by adsorption on hydrous ferric oxides, p. 485-495. In
D. Hemphill (ed.) Trace substances in environmental health. Vol. 5.
Univ. Missouri Press, Columbia, MO.
Skogerboe, R. K., C. S. Lavallee, M. M. Miller, and D. L. Dick. 1979.
Environmental effects of western coal surface mining. Part III - Water
quality of Trout Creek, Colorado. Ecol. Res. Ser., U.S. Environmental
Protection Agency, Duluth, MN. (In press)
Skogerboe, R. K., C. S. Lavallee, M. M. Miller, and D. L. Dick. 1978. Pre-
operational surface water quality conditions along Piceance Creek,
Colorado: Compilation of data. NREL-FBL Technical Rep. No. 2. Natural
Resource Ecology Laboratory, Colorado State Univ., Fort Collins, CO, and
Fisheries Bioassay Laboratory, Montana State Univ., Bozeman, MT. 73 p.
U.S. Environmental Protection Agency. 1974. Manual of methods for chemical
analysis of water and wastes. Methods Development and Quality Assurance
Laboratory, EPA-625/6-74-003, U.S. Environmental Protection Agency,
Cincinnati, OH. 298 p.
U.S. Environmental Protection Agency. 1977. Quality criteria for water.
Office of Water and Hazardous Materials, U.S. Environmental Protection
Agency, Washington, D.C. 256 p.
46
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U.S. Public Health Service. 1962. Drinking water standards. Publ. 956.
Dep. Health, Education and Welfare, Washington, D.C.
Weeks, J. B., and F. A. Welder. 1964. Hydrologic and geophysical data from
the Piceance Basin, Colorado. Colorado Water Conservation Board Water
Resources Basic Data, Release 35, Denver, CO.
Weeks, J. B., G. H. Leavesley, F. A. Welder, and G. J. Saulnier, Jr. 1974.
Simulated effects of oil-shale development on the hydrology of Piceance
Basin, Colorado. U.S. Geol. Surv. Prof. Paper 908, Denver, CO.
47
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APPENDIX A
*
EVALUATION OF HEAVY METAL EQUILIBRIA
This Appendix was taken largely from Skogerboe, R. K., C. S. Lavallee,
M. M. Miller, and D. L. Dick. 1979. Environmental Effects of Western Coal
Surface Mining. Part III - The Water Quality of Trout Creek, Colorado,
Ecol. Res. Ser., U.S. Environmental Protection Agency, Duluth, Minn.
(In press)
48
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Fairly comprehensive water quality data sets have been accumulated by
us1'2 and by state water resource agencies, USGS, and EPA for western streams.
Examination of these data indicates that the general water quality charac-
teristics are quite similar on a broad scale. Based on this examination the
following generalizations can be made.
1. Observed pH values range from 6.5 to 8.5 with more than 85% of all
values falling between 7 and 8.
2. Total alkalinity ranges from 20-1000 mg carbonate/liter with the most
common values approximating 100 mg/liter. Acidity is typically immea-
surable and rarely approaches 10 mg/liter.
3. Total hardness ranges up to 2500 mg CaC03/liter with most values lying
in the 150-200 mg/liter range.
4. Total sulfate covers the 10-2500 mg/liter range with values around 150-
200 mg/liter being most frequent.
5. Chloride concentrations rarely exceed 1 mg/liter.
6. Nitrate concentrations rarely exceed 1 mg/liter.
7. Orthophosphate levels are typically less than 0.1 mg/liter.
These parameters may be generally considered primary in controlling the
chemical equilibria which determine the solubilities of many heavy metals.
In view of the mineralogical and/or chemical characteristics of the
soils, sediments, and mine overburden/spoils of this region, the general
concentration levels of the anionic species cited above should be essentially
"fixed" in the ranges mentioned above. Moreover, the morphologies of most
western streams are such that their waters will remain in reasonable equilib -
rium with atmospheric constituents such as C02 and 02 as influenced by other
parameters such as pH, temperature, alkalinity, etc. Simply stated, the
observed ranges of pH, carbonate, alkalinity, sulfate, etc., can be defined
as generally representative of the entire western coal development region.
iSkogerboe, R. K., C. S. Lavallee, M. M. Miller, and D. L. Dick. 1978.
Effects of a surface coal mine on water quality: Trout Creek, Colorado.
Compilation of chemical data. NREL-FBL Tech. Rep. No. 1. Natural Resource
Ecology Laboratory, Colorado State Univ., Fort Collins, CO, and Fisheries
Bioassay Laboratory, Montana State Univ., Bozeman, MT. 173 p.
2Skogerboe, R. K., C. S. Lavallee, M. M. Miller, and D. L. Dick. 1978. Pre-
operational surface water quality conditions along Piceance Creek, Colorado:
Compilation of chemical data. NREL-FBL Tech. Rep. No. 2. Natural Resource
Ecology Laboratory, Colorado State Univ., Fort Collins, CO, and Fisheries
Bioassay Laboratory, Montana State Univ., Bozeman, MT. 73 p.
49
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These ranges can consequently be taken as boundary conditions in considering
the heavy metal equilibria that should prevail in the absence of unusual
circumstances. The ranges given above should, within limits, be relatively
unperturbed by the additions of other constituents such as metal ions unless
such additions involve major influxes. Consequently, equilibrium models can
be used for predicting the fates of heavy metals which may be available in
forms soluble under other conditions.
Equilibrium calculations can thus be used to estimate maximum solubili-
ties of several heavy metals under the conditions representative of the
chemical and mineralogical features of the soils and spoils and the ground
and surface waters of the area. These calculations may be made assuming that
the heavy metals in question exist in soluble forms at their origin, e.g., a
strip coal mine. If they do not, the maximum solubility calculations will be
overestimates of the actual case. It can be easily argued that such
definitions of upper limits serve as valuable reference points.
Two general types of chemical interactions may occur for a particular
metal ion and any combination of the anionic species stipulated in the above
set of generalizations. Immobilization of the metal ion due to precipitation
or to ion exchange type processes may occur. Alternatively, the ion may be
mobilized by complexation reactions which effectively enhance its solubility.
In either case, the interactions involved can be described by thermodynamic
parameters. The relative significance levels of the possible equilibria can
therefore be assessed on the basis of thermodynamic stabilities. Reactions
resulting in the largest increases in stability will tend to be principal
among the various possibilities. The compilation of equilibrium constants
published by Si 11 en and Martell3 has been used as the data source for the
present calculations.
The equilibria considered for each metal ion are listed in Appendix
Table 1. Precipitates of a complex nature [e.g., Zn(C03)0i36(OH)U28] were
not considered since such precipitates are usually formed only slowly from
simpler precipitates (e.g.. ZnC03) rather than directly in solution. They
will, therefore, not be the controlling equilibria on the time scale of
importance herein, i.e., a few days. Some other equilibria could also have
been included, but were rejected either because: (i) their equilibrium
constants were too low to be considered significant relative to those listed,
or (ii) the concentrations of the anions involved indicated a lack of signif-
icance. The equilibria in Appendix Table 1 have been written so the stoichi-
ometric coefficient of the aquated metal ion is unity. This practice has
been followed to simplify model calculations. The equilibrium constants used
in the calculations are also given in Appendix Table 1; values chosen were
for 25°C and zero ionic strength. In instances for which two or more inde-
pendent determinations of an equilibrium constant did not agree, average
values were selected for the present calculations. For metals having more
3Sillen, L. G., and A. F. Martell. 1964. Stability constants of metal-ion
complexes. Spec. Publ. No. 17. Chemical Society, London.
50
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than one common oxidation state, all states were considered because the redox
characteristics of the waters may vary significantly. In all calculations,
the pH was selected as the independent (master) variable. The common ranges
for each of the anions present, as indicated above, were used to define the
boundary conditions for the calculations. Thus, the low and high ends of the
typical concentration range for each anion were used in the calculations as a
means of defining the extremes of the controlling equilibria possibilities.
For anions that could be present in various forms, the pH-based calculations
were used to determine the relative concentrations of each form. Carbonate,
for example, may be present as dissolved C02, H2C03, HCOs~, C032~, CaHC03+,
and CaC03°. The species CaHC03+ and CaC03° are soluble complexes which,
because of the typically high levels of calcium in solution (?60 mg/liter)
may tie up a significant fraction of the total carbonate. The appropriate
equilibrium constants were consequently used to determine the respective
concentrations of each of the free carbonate species at the pH level in
question. The carbonate boundary condition concentrations, given as a
footnote to Table 5, are thus for the total of all carbonate related species.
Similar adjustments were made for other anions as required.
Since the interest is in obtaining estimates of the maximum concentration
of soluble metal, any effect which will tend to increase solubility should be
taken into account. The effect of ionic strength is such that solubilities
of metal salts will be increased at higher ionic strength; hence a correction
for ionic strength has been made; i.e., the equilibrium calculations are
carried out in terms of activities which are related to concentrations by the
relation:
a = yC.
The activity coefficient y decreases with increasing ionic strength, where
ionic strength, I, is defined by
I = h rt^2*
where z-; is the charge of the ith ionic species and Ci is its molar concen-
tration. The activity coefficients have been calculated for the typical
concentration ranges cited above via the equation:
/T
log Y±z = -A z2 ! + /T {L)
where A is a constant whose value depends only on the solvent and temperature.
This equation is generally accepted as the best available for estimating the
value of Y in an aqueous system containing more than one salt (i.e., a mixed
electrolyte system)4. Failure to include an ionic strength correction lowers
^Stumm, W., and J. J. Morgan. 1970. Aquatic chemistry. Wiley-Interscience,
New York.
51
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the calculated total metal solubilities by 5-10% for typical stream
conditions and by 530% for typical mine spoil drainage conditions.
As indicated above, reactions between metal ions and anions may involve
precipitation or complexation. The general expression for precipitation of a
metal ion, Mn+, by an anion, Am~, is:
Mn+ + n/m Am~ J 1/m MmAn (2)
and
K = (Mn )(Am~) n/m (3)
sp
where parentheses indicate the activities of the species. A similar expres-
sion for complexation would be:
and
Mn+ + qAm- 1 MA (4)
Considering the equilibria for Zn2+ as an example (Appendix Table 1) the
following expressions may be evaluated.
(Zn2+) = 1015-7/(OH-)2 (6)
(Zn2+) = 10-10-8/(C032-) (7)
(Zn2+) = 10-14^2/(C032-)0-36(OH-)1-28 (8)
(Zn2+) = lO-10-68/^3-)2/3 (9)
and
(Zn2+) = 10-13-9/(SOu2-)1/l*(OH-)3/2 (10)
Thus, for example, at pH = 7; (OH~) = 10~7 M; (PO,,3-) = lO'5 M; and total
carbonate species (C03)j = 3 x 10"3 M; it may be determined that the solu-
bility of Zn will be limited principally by carbonate precipitation (Equation
7) to a molarity of 10~5. This calculation has consequently defined the
controlling precipitate as well as the upper limit concentration of Zn2+.
The quantity of interest is the total soluble zinc which is the experimentally
determined quantity regardless of chemical form. Again referring to Appendix
Table 1, the total soluble Zn, (Zn)j, may be defined as the sum of all
dissolved Zn-containing species, i.e.,
52
-------
(Zn)T = (Zn2+)/Y±2 + (ZnOH+)/Y±l + (Zn(OH)3-)/T±l
+ (Zn(OHK2-)/Y±2 + (ZnS04°) + (ZnCl + )/Y±l + (11)
(ZnCl2°) + (ZnCl3-)/Y±l + (ZnC11+2-)/Y±2
The concentrations of each of these complexes may be expressed in terms of
the Zn2+, the appropriate anion concentration, and the respective equilibrium
constants. Equation 11 may be reduced to:
(Zn)T = (Zn2+) U/Y±2 + 105-Q1+(OH-)/Y±l
+ 1014-2 (OH-)3/y±l + 1015 (OH-)VY±1 (12)
... io°-2
Evaluation of this for the pH = 7 conditions listed above when (Zn2+) = 10"5
indicates that the total soluble Zn concentration when complexation reactions
are considered may be increased to 2.4 x 10"5 M. This coincides with a
concentration of -1.6 mg/liter. These same calculation procedures are
carried out for a given set of boundary conditions for the metals listed in
relation to pH.
53
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APPENDIX TABLE 1. EQUILIBRIA AND EQUILIBRIUM CONSTANTS
CONSIDERED IN MODEL CALCULATIONS-/
Species
H20
H2C03
H2SO,
H3PO,
Al(III)
Cd(II)
Product(s)
H+ + OH"
H+ + HC03"
H+ + C032~
CaHC03+
CaC03° y
H+ + SO,2-
CaSO^0
H+ + H PO "
+ 0
H j. UDH 2—
T (IrUij.
H+ + P0,3-
A1(OH)3
A1P04
A10H2+
A1(OH)2+
A1(OHK~
A1SO,,"1"
A1(SO,)2-
CdC03
Cd(OH)1.5(SOj0.25
1/3 Cd3(POj2
CdSO^
Cd(OH)2
CdOH+
log K
-14
-6.35
-10.34
1.26
3.2
-1.99
2.31
-2.16
-7.21
-12.33
-32.5
-18.24
9.76
19.4
28.3
3.2
5.1
-13.74
-12.5
-10.72
-7.8
-14.5
6.08
54
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Appendix Table 1.
Continued.
Species
Cd(II) (cont.)
Cu(II)
Hg2(II)
Product(s)
Cd(OH)2°
Cd(OH)"
Cd(OHK2-
CdS04°
CdCl +
CdCl2°
CdCl3"
CdCV'
Cu(OH)2
CuC03
1/3 Cu3(P04)2
CuOH+
Cu(OH)2°
Cu(OH)3"
Cu(OHK2-
1/2 Cu2(OH)22+
CuC03°
Cu(C03)22-
CuC03OH"
CuS04°
CuCl +
Hg2co3
Hg^PO^
log K
8.7
8.38
8.42
2.3
1.95
2.5
2.35
1.65
-19.7
-9.63
-12.3
6.66
14.32
15.5
13.8
5.26
6.34
10.01
15.0
2.35
0.95
-16.05
-12.4
55
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Appendix Table 1. Continued.
Species
Hg2(II) (cont.)
Hg(II)
Mn(II)
Pb(II)
Product(s)
Hg2Cl2
Hg2OH+
Hg2S01+°
Hg2(soj22-
Hg(OH)2
HgOH+
Hg(OH)2°
Hg(OH)3~
Hg(OHK2-
HgSO^0
Hg(soj22-
HgCl +
HgCl2°
HgCl3"
HgCV"
Mn(OH)2
MnC03
MnOH"1"
Mn(OH)3"
MnHC03+
MnSO^0
Pb(OH)2
PbC03
log K
-17.88
9.0
1.3
2.4
-25.4
10.2
22.66
21.8
21.3
1.34
2.44
6.74
13.22
13.79
15.25
-12.8
-9.3
3.41
1.8
1.8
2.26
-18.7
-13.4
56
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Appendix Table 1. Continued.
Species Product(s)
Pb(II) (cont.) 1/3 Pb3(P01+)2
PbHP04
PbCl2
PbS04
PbOH+
Pb(OH)2°
Pb(OH)3"
Pb2OH3+
Pb4(OH)^+
PbCl +
PbCl2°
PbCl3"
PbCV
PbSO^0
Zn(II) Zn(OH)2
ZnC03
1/3 Zn3(P01+)2
ZnOH+
Zn(OH)3"
Zn(OHK2~
ZnSO^0
ZnCl +
log K
-14.03
-9.9
-4.76
-7.8
6.22
10.34
13.95
6.7
35.7
1.6
1.78
1.68
1.38
2.46
-15.7
-10.8
-10.68
5.04
14.2
15.0
2.26
0.43
57
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Appendix Table 1.
Continued.
Species
Zn(II) (cont.)
Fe(II)
Fe(III)
Product(s)
ZnCl2°
ZnCl3-
ZnCV-
Fe(OH)2
FeC03
FeOH+
Fe(OH)3"
Fe(OHK2-
Fe(OH)3
FePO^
Fe(OH)H2POit
FeOH2+
Fe(OH)2+
Fe(OHK2-
FeSO,+
FeCl2+
Fe(S01+)2"
log K
0.61
0.53
0.2
-15.1
-10.6
5.7
10.0
9.6
-38.6
-30.02
-34.56
11.81
20.84
24.54
4.10
1.48
5.44
-/Sillen, L. 6., and A. F. Martell. 1964. Stability
constants of metal-ion complexes. Spec. Publ. No. 17.
Chemical Society, London.
— Superscript ° indicates the compound in soluble form.
58
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TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
1. REPORT NO.
EPA-600/3-79-055
3. RECIPIENT'S ACCESSION NO.
4. TITLE AND SUBTITLE
Environmental Effects of Oil Shale Mining and
Processing Part III - The Water Quality of Piceance
Creek. Colorado, Prior to Oil Shale Processing
5. REPORT DATE
May _1979 issuing
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
R. K. Skogerboe, C. S. Lavallee, M. M. Miller,
D. L. Dick
8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Department of Chemistry
Colorado State University
Fort Collins, Colorado 80523
10. PROGRAM ELEMENT NO.
1NE831
11. CONTRACT/GRANT NO.
R803950
12. SPONSORING AGENCY NAME AND ADDRESS
ENVIRONMENTAL RESEARCH LABORATORY - Duluth Minnesota
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
DULUTH, MINNESOTA 55804
13. TYPE OF REPORT AND PERIOD COVERED
Final
14. SPONSORING AGENCY CODE
EPA/600/03
15. SUPPLEMENTARY NOTES
16. ABSTRACT
Water quality data have been collected at seven sites along Piceance Creek and
at one site each along Stewart, Black Sulphur, and Yellow Creeks in the Piceance
Basin, Colorado, during 1975-1977. Piceance, Stewart, and Yellow Creeks may be
perturbed by oil shale industry activities on the two tracts, C-a and C-b, currently
under development. The preoperational water quality is generally poor due to higher
levels of dissolved solids, manganese, and both dissolved and suspended iron. It
further declined farther downstream primarily due to influxes from groundwater aquifers
in contact with soluble mineral beds. The levels of aluminum, cadmium, chromium,
lead, and boron were below the detection limits of the analysis method used. These
were typically below the permissible levels set for aquatic life by factors of 5-10.
The levels of copper, zinc, arsenic, selenium, and mercury were usually measurable
but still below permissible.
Equilibrium calculations indicate that the natural conditions along Piceance
Creek—in particular the alkaline pH range (7.5-8.5) and high carbonate alkalinity
(300-800 mg CaC03/liter)-should limit the solubilities of most metals to levels below
the standards for aquatic life.
17.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
Metals
Trace elements
Equilibrium calculations
Oil shale
Metal equilibria
Water chemistry
b.IDENTIFIERS/OPEN ENDED TERMS
Energy development
Water quality
Effects of mining
Chemical surveys
c. COSATl Held/Group
06/F
13/B
18. DISTRIBUTION STATEMENT
RELEASE TO PUBLIC
19. SECURITY CLASS (This Report)
UNCLASSIFIED
21. NO. OF PAGES
69
20. SECURITY CLASS (This page)
UNCLASSIFIED
22. PRICE
EPA Form 2220-1 (Rev. 4-77) PREVIOUS EDITION is OBSOLETE
59
. S. GOVERNMENT HUNTING OFFICE: 1979-657-060/1664 Region No. 5-11
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