METALS ASSESSMENT OF SILVER BOW CREEK
BETWEEN BUTTE AND GREGSON, MONTANA
Alan E. Peckham
June 1979
National Enforcement Investigations Center
Denver, Colorado
-------
CONTENTS
I INTRODUCTION 1
II SUMMARY AND CONCLUSIONS 3
Summary of Investigation .... 3
Conclusions 5
III BACKGROUND 8
History of Mining Impact .... 8
Topography, Climate and Geologic
Setting 10
IV SAMPLING PROGRAM 12
Stream and Point Source
Sampling 12
Groundwater Sampling 16
Tailings Sampling 16
Sampling Problems 17
V ANALYTICAL RESULTS 18
Stream Quality 18
Groundwater Quality 28
Tailings 28
Stream Rehabilitation 30/
REFERENCES
APPENDICES
A STATION DESCRIPTIONS
B CHEMICAL ANALYSES
C ANALYTICAL METHODOLOGY
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TABLES
1 Stream Flow Data, Silver Bow Creek and
Tributaries Between Butte and Gregson,
Montana 13
2 Calculated Chemical Loads, pH and Specific
Conductance - Silver Bow Creek and Tributaries
Between Butte and Gregson, Montana 23
3 Metals Analyses of Tailings and Groundwater
Samples (Silver Bow Creek Between Butte and
Gregson, Montana 29
FIGURES
1 Silver Bow Creek Between Butte and Gregson,
Montana 4
2 Silver Bow Creek Flow Between Butte and
Gregson, Montana - High, Low and Average
Flow of three Measurements 14
3 Total and Dissolved Copper Load - Silver Bow
Creek Between Butte and Gregson, Montana.
High, Low and Average Values at Each Main
Stem Station 19.
4 Total Iron Load - Silver Bow Creek Between
Butte and Gregson, Montana. High, Low and
Average Values at each Main Stem Station ... 20
5 Total and Dissolved Zinc Load - Silver Bow
Creek Between Butte and Gregson, Montana.
High, Low and Average Values at each Main
Station 21
6 Chloride Plus Sulfate Load - Silver Bow Creek
Between Butte and Gregson, Montana. High, Low
and Average Values at Each Main Stem Station . 22
7 pH Record from Silver Bow Creek Station No. 80
for the period 10/19/78 to 10/21/78 26
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I. INTRODUCTION
This investigation was in response to a request to the National
Enforcement Investigations Center (.NEIC) from EPA Region VIII for a
heavy metals assessment of Silver Bow Creek, a tributary to the Clark
Fork River in southwestern Montana. The reach studied is a 24 km (17
mi) portion of the Creek between the west edge of Butte, below the con-
fluence of Silver Bow and Blacktail Creeks, and Gregson, Montana.
Mining operations started along Silver Bow Creek with the discovery
of gold in 1864. In the following decades, silver, copper, zinc, man-
ganese and lead were also mined. The present-day truck-operated open
pit mining operation at the Anaconda Company's Berkeley Pit is the
largest in the country. Because of the extensive and sustained mining
operations in the vicinity of Butte, the hill on which Butte and the
mine are located has become known as "The Richest Hill on Earth."
During most of the history of mining in the Butte area, mine tailings and
other debris from the mining industry were dumped into Silver Bow Creek
and large accumulations of these materials have been deposited along the
flood plain of the Creek. These accumulations contain a large inventory
of residual metals which adversely influence the environment, affect
both shallow groundwater and surface water quality, and may impact the
viability of an aquatic life in the Creek.
In response to Region VIII's request for NEIC to assess the effects
of the old tailings accumulations on Silver Bow Creek, the following
objectives were established:
1. Determine the heavy metals load being added to Silver
Bow Creek from mine tailings residues along its flood plain.
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2
2. Determine the volume and distribution of mine tailings de-
posited in the stream bed and flood plain of Silver Bow Creek
between Butte and Gregson, Montana.
3. Determine the metals concentrations of these tailings.
4. Assess procedures for eliminating or minimizing the metals
pollution along the course of Silver Bow Creek.
To meet the above objectives, field studies were conducted in the
summer and fall of 1976.^ In August 1978, a reconnaissance was under-
taken to develop information on the current status of the environment
of Silver Bow Creek and provide the basis for completing the project.
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II. SUMMARY AND CONCLUSIONS
SUMMARY OF INVESTIGATION
This investigation was designed to determine the distribution of
metals pollution from old mine tailings along Silver Bow Creek, the
relative importance and the transport of these metals in the Creek
between Butte and Gregson, Montana. Sampling and gaging sites on the
main stem of the Creek and all significant tributary flows in the study
reach were selected [Figure 1]. In addition, shallow groundwater and
tailings samples were collected from hand-augered holes in the tailings
deposits adjacent to the Creek. A continuous record of pH was main-
tained at the furthest upstream main-stem station throughout the survey.
Samples and flow data were collected from each of the principal
stations three times during the survey. Some previously unrecognized
and some intermittent flows were discovered during the survey and,
although these were sampled and gaged, they were not included in all
three sample runs.
Stream flow and water quality data were used to calculate and
illustrate metals loads incrementally throughout the study reach of
Silver Bow Creek.
Aerial photographs, topographic maps and thickness of tailings,
determined by depths of auger holes, were used to estimate the volume of
old mine tailings distributed along the Creek. Analyses of tailings and
groundwater samples were used to estimate the metals content of tailings
and determine the quality of shallow groundwater which discharges into
Silver Bow Creek.
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F---3 TAILINGS
Figure I. Silver Bow Creek between Butte and Gregson, Montana
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5
Assessments were made of alternative means of reducing polllution
in Silver Bow Creek. These include removal of tailings from the Creek
floodplain, minimizing leachate from the tailings into the Creek and
control of point source discharges. The potential effects of the com-
bined sources of pollution on the stream quality were also assessed.
Interpretation of the analytical data leads to the following con-
clusions:
CONCLUSIONS
Total copper, iron and zinc loads increase significantly in
Silver Bow Creek between Butte and Gregson, Montana. Total copper
increases from about 15 kg (32 lb)/day to about 37 kg (80 lb)/day,
total iron increases from about 110 kg (240 lb)/day to about 200
kg (440 lb)/day and total zinc increases from about 32 kg (70
lb)/day to about 130 kg (280 lb)/day in the study reach. Of
these addditions, it is calculated that 84% of the copper,
99% of the iron and 46% of the zinc are from non-point sources.
A large volume of old mine tailings occurs along the study reach
of Silver Bow Creek. Approximately. 1.7x10^ (2.3xl0^yd^) of
these tailings are distributed along the flood plain of the Creek
between Butte and Gregson, Montana. This estimate is based on an
co fi 9
area of about 1.2x10 m (1.5x10 yd ) and thicknesses ranging from
less than one meter (3 feet) to more than three meters (10 feet).
The data show a wide range in concentration for copper and zinc
in the.tailings samples. Copper and zinc concentrations ranged
from 69 to 20,000 ug/g and 460 to 22,000 yg/g, respectively. From
these data, it is conservatively estimated that there are about
9xl0^kg (20xl06lb) copper and 18xl0^kg (39x10^1b) zinc in the
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6
tailings deposits. These estimates are based on the area and
thickness data and on metals concentration data of tailings sam-
ples from auger holes.
Removal of tailings deposits from the Silver Bow Creek flood
plain would reduce but probably not eliminate metals pollution of
the Creek. Although removing these deposits would subsequently
reduce the leachate, the removal process would cause serious prob-
lems with turbidity and sudden release to the stream of large
volumes of stored, shallow, highly mineralized, low pH groundwater.
Covering the tailings deposits with clay and soil and revegitating
the surface would not significantly reduce the. metals leachate
discharging into the Creek. Groundwater will continue to flow
through the tailings from the uplands to discharge points along the
Creek and mineral deposits will continue to collect as evaporites
on the soil surface and will periodically be washed into the stream
during heavy runoff.
Because "of the poor and rapidly changing quality of the Anaconda
Co. and City of Butte SPT discharges into the upper reach of Silver
Bow Creek, the effect of groundwater contributions cannot be pre-
cisely quantified. As an example, the pH of the stream upstream of
the Butte STP ranged from 3.3 to 11.5 during one 33-hour period.
The Butte STP bypassed raw sewage to Silver Bow Creek during two
periods totaling about thirty hours during this survey. Such
interferences preclude a rigorous metals evaluation of the
stream until such major point source discharges are stabilized.
The results of this study indicate it may not be feasible to reduce
metals concentrations in Silver Bow Creek to levels tolerable to
aquatic life. Chemical analyses of the water of Silver Bow Creek
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7
show copper and zinc that are potentially toxic to fish. The bio-
logical impact of the effluent discharge from the Butte STP on Sil-
ver Bow Creek is unknown, however municipal wastewater commonly con-
tains acutely toxic concentrations of un-ionized ammonia and residual
chlorine.
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III. BACKGROUND
HISTORY OF MINING IMPACT
Silver Bow Creek is a natural headwater tributary of the Clark
Fork River. It has been environmentally degraded by mining-related
2
operations for about one hundred years. Historically, mine drainage,
tailings and ore milling/concentrating wastewater effluents have been
discharged directly into the Creek near Butte, Montana. For many years
these discharges have made the stream unsuitable for support of aquatic
life. Additionally, the deposition of tailings and other mining/ mill-
ing solid materials altered the Creek's configuration between Butte and
Warm Springs, Montana, some 38 km (24 mi) downstream [Figure 1].
As mining and milling technology evolved, the character of wastes
from the Butte area operations changed. During the 1950s, the major
discharges of solid mine tailings were curtailed and efforts were made
to control the quality of wastewater discharges to the headwaters of
3
Silver Bow Creek.
In the early 1970's, the Anaconda Company, which was primarily the
Company responsible for most mining and milling activities in the area,
modified their process operations to reduce the quantity and improve the
qua!ity of. their wastewater discharges. Treatment processes were also
installed or modified to improve the quality of the wastewater. The
water quality of Silver Bow Creek was reported to have improved substan-
tially because of these modifications.
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9
Additional improvements at the Company's Anaconda and Warm Springs,
Montana facilities, coupled with the water quality improvement of Silver
Bow Creek, have led to the reestablishment of a biological community
in the Clark Fork River downstream from Warm Springs. Fish population
studies conducted by the Montana Fish and Game Department during 1967
and 1969 showed that no fish species existed immediately downstream from
Warm Springs. Similar studies conducted between the spring of 1972 and
spring of 1974 indicated a gradual improvement of the River as a sport
fishery. By the spring of 1974 a substantial population of brown trout
4
and other game fish was established in this same area.
The recovery of the Clark Fork River as a sport fishery stimulated
interest in the possibility of a similar recovery of Silver Bow Creek.
Anaconda Company personnel reported that, from 1973 to 1975, aquatic
3
life had been re-established in the Creek. Benthic organisms such as
midge and crane fly larvae were reported near Gregson, Montana. Blue-
green algae, yellow-green algae, and diatoms were reported throughout
the entire length of the Creek below Butte. Although the predominant
species of organisms suggested that environmental stresses still existed
in the aquatic habitat, the presence of any life was encouraging. It
was apparent, however, that pollutant contributions to the Creek would
have to be decreased before the habitat could support game fish. Thus,
definition of both point and non-point source pollutant loads to the
Creek became an important issue to the Company, the State of Montana and
to EPA in the mid-1970's.
In 1976, the NEIC investigated metals in mine tailings, shallow
groundwater and the potential impact of groundwater discharge on stream
quality. However, this early work did not evaluate overall stream water
quality as it is influenced by the major headquarter components.^
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10
TOPOGRAPHY, CLIMATE AND GEOLOGIC SETTING
The Silver Bow Creek flows westward from Butte to Gregsop, Montana
and then northward to Warm Springs where it is joined by Mill Creek,
Willow Creek, Warm Springs Creek and other small intermittent drainage
channels to form the Clark Fork in the headwaters of the Columbia River
[Figure 1]. Silver Bow Creek Valley is a typical intermountain valley
containing recent alluvial sands and gravels. The latter have been
overlain by mine tailings discharged into the Creek since mining opera-
tions began near Butte in the late 1800's. These mine tailings were
deposited along the flood plain when the volume of tailings became
greater than the transport capacity of the stream. Other factors such
as ice jams and periodic accumulation of debris also contributed to the
deposition of mine tailings.
The major topographic characteristics of the valley have probably
not changed since the valley was settled by early miners. However, the
effects of mine tailings along the creek channel have obscured the
virgin nature of the Creek itself and have had major effects on the
water quality and flow characteristics of the Creek in the reach between
Butte and Gregson. The Creek meanders through the alluvial channel and
is braided in those reaches where tailings have been deposited upstream
of channel constrictions, such as in the vicinity of Ramsay and Miles
Crossing. Downstream from the bedrock constriction in the valley below
Miles Crossing, there are very few tailings deposited along the channel
and, in the few spotty areas where they do occur, they consist of a
veneer of one foot or less in thickness.
The climate and stream flow characteristics of the area have in-
fluenced the distribution of tailings deposied along Silver Bow Creek.
The.area is arid, having an annual average precipitation of about 29.2
cm (11.5 in).^ Most of this occurs in the spring and summer months.
The mean minimum temperature is below freezing from October through
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11
April. Apparently, ice accumulations arid other debris have caused
the Creek to flood at various times and places during the years when
large amounts of tailings were being dumped into the Creek from mining
4
operations in the Butte area. Upstream of the bedrock constriction
in the valley, below Miles Crossing and at other locations upstream of
several railroad bridges supported by large pilings, there are larger
and thicker deposits of tailings than in other reaches of the stream.
Some of these deposits range up to a mile or more long* a quarter of
a mile wide and more than ten feet thick as determined by hand auger
borings made during the October 1978 survey.
Underlying the alluvial fill in the valley is a complex series of
mineralized igneous and volcanic rocks of generally low permeability.
Groundwater does circulate through fractures and other avenues of
secondary openings in these rocks from recharge areas in the uplands
to the Silver Bow Creek drainage. This area constitutes a groundwater
discharge area throughout most of the study reach. These flows will
continue to contribute mineralized waters to the flow of Silver Bow
Creek.
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IV. SAMPLING PROGRAM
STREAM AND POINT SOURCE SAMPLING
Five surface water sampling sites were selected along the main stem
of Silver Bow Creek between Butte and Gregson [Figure 1] [Appendix A].
With the exception of the reach between the two furthest downstream
sites [Stations 88,and 89], there are large deposits of old mine tail-
ings between each site. In addition, sitas on tributary streams and
other flow sources were selected.
The original plan was to measure stream flows daily and sample each
site for three consecutive days. However, intermittent discharge of raw
sewage into Silver Bow Creek by the Butte STP and the intermittent
discharge of fresh pipeline water to the Creek near Ramsay necessitated
altering the sampling schedule.
Construction activities at the Butte STP necessitated bypassing raw
sewage directly into Silver Bow Creek on two occasions during the inves-
tigation. This action hampered flow gaging, sampling and filtering of
samples from the STP (Station No. 81) and from all downstream stations
in the main stem of Silver Bow Creek.
Flow measurements were made at each flow sampling site at the time
of collection of each sample [Table 1 and Figure 2].
Also, three previously unrecorded tributary flows were discovered
during the investigation. These include small flows from a seep below
the Stauffer Chemical Plant and from a wooden pipe which drains ground-
water from a tailings deposit on the north side of Silver Bow Creek in
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Table 1
STREAM FLOW DATA, SILVER BOW CREEK AND
TRIBUTARIES BETWEEN BUTTE AND GREGSOM, MOfiTAMA
Station and
Sequence
Date
ftJ/sec
T/sec
•83-02
10/18/78
0.27
'7.7
-83-03
10/20/78
0.18
5.1
¦83-04
10/22/78
0.17
4.8
80-02
10/16/78
"17.45
494
80-03
10/17/78
.20.66
585
80-04
10/18/78
=25.39
719
30-05
10/20/78
24.27
587
80-05
10/20/78
20.96
594
-81-02
10/19/78
8.28
234
81-03
10/20/78
7.18
203
81-04
10/21/78
7.41
210
-82-02
70/18/78
0.75
4.34
82-03
10/20/78
0.18
5.1
S2-04
10/22/78
0.19
5.5
B4-02
10/18/76
32.05
903
8^-S3
10/20/78
31.92
904
•84-04
10/22/78
32.41
913
92-01
10/24/78
0.02
0.7
•85-01
10/24/78
0.17
4.7
96,01
10/25/78
1.76
50
86-01
10/21/78
16.59
470
•86-02
10/22/78
16.67
472
87-02
10/19/78
33.06
936
•87-03
10/21/78
42.26
1310
•87-04
10/22/78
4 9.9
1413
88-02
10/19/78
40.44
1145
88-03
10/21/78
47.48
1344
83-04
10/22/78
49-93
1414
89-02
10/19/73
47.16
1335
89-03
10/21/78
57.28
1622
89-04
10/22/78
58.63
1660
* Large flows were oaged by use of a MarshMcBiniey flow meter;
small flows by use of a calibrated bucket add stop watch.
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16 8 O—
1400-
Zi 1120-
VI
CO
C£
UJ
— 8 4 0—1
560-
280-
FLOW - H 16 H, LOW AND AVERAGE
P i
\
STATION NO. 80 WAS GAGED 5 TIMES
O-i-
T
0
1
80
1
nr
16
I I I I I \
4 6 8 10 12 14
STREAM KILOMETERS
I I I
84 87 88
STATION NUMBERS
18
2 O
I
2'2
24 25
I
89
Figure 2. Silver Bow Creek Flow between Butte and Gregson, Montana
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15
the vicinity of Silver Bow. These flows' are at Station 85, and at
Station 92. One large pipeline flow at Station No. 86 [Figure 1] -
commenced during the investigation and was gaged and sampled on the
second and third rounds of sampling. This discharge emanated from a
large 46x91cm (18x36 inch) rectangular outfall structure in the hillside
which forms the north bank of Silver Bow Creek about 1.6 km (1 mile)
east'of Ramsay and flowed through a short channel directly into the
Creek. This discharge, which is intermittant, had not occured during
any visit prior to October 21, 1978 and, judging from field measurements,
was fresh water (specific conductance of only 260 ymhos/cm). The dis-
charge comes from a pipeline which normally transmits process water from
Silver Lake, about 21 km (13 miles) west of Anaconda, to the Anaconda Co.
in Butte. The reason for discharging this high quality water into
Silver Bow Creek was not determined. However, the effects of this dis-
charge were to augment the stream flow and dilute the dissolved consti-
tuents in the Creek.
These newly discovered flow contributions to Silver Bow Creek in the
study reach influenced the flow regimen and water quality characteris-
tics of the stream so that results of this survey are more difficult to
interpret than had the observations been made under a controlled steady-
state, low flow regimen.
One of the principal objectives of the survey was to evaluate the
dissolved metals contributions to Silver Bow Creek from leaching of the
tailings which are distributed along the flood plain. This objective
was reasonably achieved but is not highly quantitative because of the
difficulties caused by the sampling problems discussed.
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16
Near Butte, Silver Bow, Ramsay and Miles Crossing, blue, green and
white deposits were observed on the surface of tailings deposits adja-
cent to the Creek. These deposits consist of copper sulfate and gypsum
remaining after the evaporation of shallow groundwater which is drawn to
the surface by capillary action. It is assumed that during significant
runoff events, including spring thaw and runoff, considerable amounts of
these deposits will enter the stream either by solution or by mechanical
erosion. Thus, large quantities of metals are being removed from tail-
ings deposits but, because of high discharge rates during these events,
it is not likely that metals concentrations in the stream would escalate
GROUNDWATER SAMPLING
Groundwater samples were obtained from four auger holes, the ground-
water drain at the STP construction site and the old wooden pipe ground-
water drain in the bank of Silver Bow Creek at Silver Bow [Appendix A].
The auger hole samples were collected by bailing the completed holes
with a plastic bailer on a hand-held cord and were filtered immediately
after collection. The groundwater samples were analyzed for selected
dissolved metals. Three of the auger holes penetrated the tailings and
entered the underlying black clay soil above the water table and it was
not possible to obtain groundwater samples from these holes.
TAILINGS SAMPLING
One to three tailings samples were collected from each of seven
auger holes located in the various tailings deposits along the Creek
[Appendix A]. These samples were analyzed for selected metals to aid
in determining whether these old tailings are rich enough to contribute
toxic quantities of metals pollution to the Creek.
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17
SAMPLING PROBLEMS
While making the field observations reported in this study, there
were several unexpected events. The construction activities at the
Butte STP resulted in the bypass of raw sewage into Silver Bow Creek
(SBC) on two occasions near the beginning of the study. The bypass of
the raw sewage was corrected before observations were completed but the
stream was not completely flushed; identifiable raw sewage debris was
evident throughout the observation period. The effect which this dis-
charge had upon stream quality during the study was not evaluated.
However, this interference caused disruption (because of sample filtra-
tion problems) in the sample collection schedule and affected compara-
bility of data from the several main stem sampling stations.
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V. ANALYTICAL RESULTS
STREAM QUALITY
The calculated chemical load data for Silver Bow Creek arid tri-
butaries between Butte and Gregson, Montana are presented in Table 2.
In general, the total loads of copper, iron and zinc increase down-
stream, as would te expected. However, because of the high degree of
variability in flows of differing quality and the fact that all samples
are grab samples, it is not possible to rigorously quantify the chemical
balance of the stream in the reach studied. Also, the time intervals
between sampling at different stations result in the data not being
representative of stream conditions at any one time. Nevertheless,
Figures 3, 4 and 5 show the general increases in the metals load down-
stream between Butte and Gregson between October 18 and 22, 1978.
During the period of the survey, total copper increased from about 14.5
kg/day (32 lb/day) to about 36.5 kg/day (80 lb/day), total iron from
about 110 kg/day (242 lb/day) to 202 kg/day (444 lb/day) and total zinc
from about 32 kg/day (70 lb/day) to about 128 kg/day (282 lb/day) in
the study reach. Of these additions, it is calculated that 84% of the
copper, 99% of the iron and 46% of the zinc are from non-point sources.
There is some variation in the sum of the chloride and sulfate
loads in the main stream [Figure 6], but not as large a percentage
variation as in the metals. This is attributed to the upstream con-
tribution of sulfate (sulfuric acid used to acidify the concentrator
effluent at the head of the stream) which is sufficiently high to mask
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50-
4 0-8
30-
2 0-
10-
TOTAL COPPER - HIGH, LOW AND AVERAGE
¦4---—
DISSOLVED COPPER — HIGH, LOW AND AVERAGE
JL-
—s
0—j r
T-*
1 I" I I ri „r , j ' "" I i "i " "Y" |"^1
0 2 4 6 8 10 12 14 16 18 20 22 24 25
STREAM KILOMETERS
I
80
A
I I
87 STATION NUMBERS 88
I
89
Figure 3. Total and Dissolved Copper Load,
Silver Bow Creek between Butte and Gregson, Mo nta na
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280-
TOTAL IRON - HIGH, LOW .AND AVERAGE
240-
-
200
>- 160—
a
m
120-
8 0—a
4 0-
0-S
T
2
T
6
T
8
i- r
nr
14
10 12
STREAM KILOMETERS
le
18
i i Tri
20 22 24 25
80
I
84'.
I
I
87 STATION NUMBERS 68
89
Figure 4. Total Iron Lo ad,
Silver Bow Creek between Butte and G re g s o n, Montana
o
-------
17 0-,
150
~
130-
110-
>-
!* 9 0-5
u>
70-
5 0-
3 0-
1 0-
TOTAL ZINC - HIGH, LOW AND AVERAGE
/
/
/
/
Y
/
/ .
/
/
/
/
/ /
/ /
A—
4^
/
/
/
DISSOLVED ZINC - HIGH, LOW AND AVERAGE
I*
/
T"
2
T
4
n
6
8
1 0
12
'1 6
STREAM KILOMETERS
18
20
r
22
24 2 5
a'o
it
87 STATION NUMBERS s's
Figure 5. Total and Dissolved Zinc Load,
Silver Bow Creek between Butte and Gregson, Montana
h
ro
-------
7 0-
6 0-1
5 0~|
n
O
— 4 0-
x
< 30^
o
o 2 0 —
1 0-
o-;
V
I
1
CHLORIDE PLUS SULFATE - HIGH, LOW AND AVERAGE
8
T
X
14
"l"
16
STREAM KILOMETERS
T*
18
nr
2 O
22
24 25
I
80
I
84
I I
87 STATION NUMBERS 88
I
89
Figure 6. Chloride Plus Sulfate Load,
Silver Bow Creek between Butte and Gregson, Montana
no
no
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Table 2
CALCULATED CHEMICAL TRANSPORT LOADS, pH AND SPECIFIC CONDUCTANCE
SILVER BOW CREEK AND TRIBUTARIES BETWEEN BUTTE AND GREGSON, MONTANA
Main
Main
Main
Main
Main
Trib
Stream
Trib
Stream
Trib
Stream
Trib
Stream
Trib
Stream
Cu
Cu
Fe
Fe
Zn
Zn
CI
CI
S04
S04
pH
Cond
Station
Sequence
Station Description
kg/day
kg/day
kg/day
kg/day
kg/day
kg/day
kg/day
kg/day
kg/day
kg/day
S.U.
pmhos/cm
83
02
Butte Storm Drain
1-6 Th
1.73T
6.39T
14.6
146.0
6.6
750
83
02
Butte Storm Drain
0.25D°
4.99D
83
03
Butte Storm Drain
0.71T
0.48T
3.97T
9.7
92.5
7.2
900
83
03
Butte Storm Drain
0.41D
3.30D
83
04
Butte Storm Drain
0.91T
0.11T
4.98T
10.4
112.0
7.2
950
83
04
Butte Storm Drain
0.17D
3.730
80
04
SBCc - Upstream, old wood bridge
6.07T
61.5T
25.5 T
683
37,273
6.6
1,025
80
04
SBC - Upstream, old wood bridge
-0- D
14.9 D
80
05
SBC - Upstream, old wood bridge
26.09T
190.OT
43.3 T
594
49,266
8.6
1,200
80
05
SBC - Upstream, old wood bridge
-0- D
2.97D
80
06
SBC - Upstream, old wood bridge
11.28T
77. OT
29.8 T
462
36,952
7.3
1,800
80
06
SBC - Upstream, old wood bridge
2.97D
15.4 D
81
02
Butte STP Effluent
3.44T
32.3 T
46.5 T
404
1,415
6.7
500
81
02
Butte STP Effluent
2.22D
40.4 D
81
03
Butte STP Effluent
4.74T
112.3 T
38.6 T
333
877
7.0
525
81
03
Butte STP Effluent
1.40D
24.6 D
81
04
Butte STP Effluent
2.00T
4.7 T
30.8 T
399
1,814
6.9
700
81
04
Butte STP Effluent
2.18D
34.5 D
82
02
Groundwater Drain at STP
0.04T
0.37T
12.4 T
12
255
6.5
1,800
82
02
Groundwater Drain at STP
0.04D
12.75D
82
03
Groundwater Drain at STP
0.04T
0.44T
11.9 T
12
234
6.4
1,400
82
03
Groundwater Drain at STP
0.050
11.9 D
82
04
Groundwater Drain at STP
0.05T
0.45T
12.8T
13
271
6.0
1,650
82
04
Groundwater Drain at STP
0.06D
13.8 D
84
02
Silver Bow Creek - Alloy Siding
21.2 T
125.5T
86.3 T
1,177
34,519
6.8
975
84
02
Silver Bow Creek - Alloy Siding
6.3 D
23.5 D
84
03
Silver Bow Creek - Alloy Siding
15.6 T
85.9T
73.4 T
1,093
40,615
7.3
1,500
84
03
Silver Bow Creek - Alloy Siding
7.8 D
73.4 D
84
04
Silver Bow Creek - Alloy Siding
18.2 T
119.OT
95.2 T
1,190
57,107
7.1
2,000
84
04
Silver Bow Creek - Alloy Siding
7.9 D
69.8 D
86
01
Rectangular Orifice
40.6
406
7.0
260
86
02
Rectangular Orifice
9.38T
40.8
408
7.4
280
87
02
Silver Bow Creek, E. Ramsay -
16.2 T
105.IT
97.04T
809
27,496
6.6
900
Railroad Bridge
87
02
Silver Bow Creek, E. Ramsay -
4.04D
88.96D
Railroad Bridge
87
03
Silver Bow Creek, E. Ramsay -
21.5 T
135.8T
10G.4 T
1,132
38.483
6.0
725
Railroad Bridge
-------
Table 2 (Cont'd)
CALCULATED CHEMICAL TRANSPORT LOADS, pH AND SPECIFIC CONDUCTANCE
SILVER BOW CREEK AND TRIBUTARIES BETWEEN BUTTE AND GREGSON, MONTANA
Main Main Main Main Main
Trib Stream Trib Stream Trib Stream Trib Stream Trib Stream
Cu Cu Fe Fe Zn Zn CI CI S04 S04 pH Cond
Station Sequence Station Description . kg/day kg/day kg/day kg/day kg/day kg/day kg/day kg/day kg/day kg/day S.U. pmhos/cm
87
03
Silver Bow Creek,
E. Ramsay -
5.66D
82.62D
Railroad Bridge
87
04
Silver Bow Creek,
E. Ramsay -
25.6 T
170.9T
122.1 T
1,221
53,717
7.1
1,300
Railroad Bridge
87
04
Silver Bow Creek,
E. Ramsay -
6.1 D
78.13D
Railroad Bridge
85
01
Sand Creek at Confluence w/SBC
60.9
447
6.6
2,800
96
01
Browns Gulch at I
-90
2.2
35.0
1,900
7.3
520
88
02
Silver Bow Creek
- Miles Crossing
26.7 T
158.3T
148.4 T
1,385
35,614
6.3
1,150
88
02
Silver Bow Creek
- Miles Crossing
7.9 D
97.940
88
03
Silver Bow Creek
- Miles Crossing
26.7 T
162.6T
139.35T
1,277
38,320
6.8
1,050
88
03
Silver Bow Creek
- Miles Crossing
5.81D
81.290
88
04
Silver Bow Creek
- Miles Crossing
37.9 T
232.IT
158.8 T
1,344
45,203
6.9
1,150
88
04
Silver Bow Creek
- Miles Crossing
6.11D
87.96D
89
02
Silver Bow Creek
- Gregsan Bridge
25.4 T
138.4T
85.35T
923
24,222
6.5
750
89
02
Silver Bow Creek
- Gregsan Bridge
10.4 D
41.5 D
89
03
Silver Bow Creek
- Gregsan Bridge
33.6 T
196.2T
114.9 T
1,401
36,437
7.4
950
89
03
Silver Bow Creek
- Gregsan Bridge
9.81D
47.65D
89
04
Silver Bow Creek
- Gregsan Bridge
51.6 T
272.5T
186.5 T
1,865
51,633
7.6
1,150
89
04
Silver Bow Creek
- Gregsan Bridge
10.04D
81.75D
a = total
b = Dissolved
c = Si 1ver Bow Creek
ro
-t5»
-------
25
the influence of smaller downstream additions. The chloride concen-
trations are low, ranging from 3 to 16 mg/1 (average 11) on the main
stem whereas sulfate ranged from 210 to 830 mg/1 (average 460).
The ranges in anion concentrations of samples was larger when tri-
butary flows were included but these contributions are small when com-
pared with the total load. The total load of chloride and sulfate shows
no increase in the main stem of Silver Bow Creek between Butte and
Gregson. This indicates that the principal source of these ions, which
are usually considered not to be involved to a significant extent in ion
exchange reactions, is the effluent from the Anaconda Co. Weed Concen-
trator at the mill in Butte near the head of the Creek.
The increases in total loads of copper, iron and zinc represent
additions of these metals from tributary sources and from ground-
water discharge into Silver Bow Creek along the study reach. The large
increases in the loads of these metals between main stem Stations 87 and
88 [Figures 3, 4, 5] indicate a large contribution from the extensive
tailings deposits in the vicinity of Ramsay.
During this survey, the pH of Silver Bow Creek at Station 80,
upstream of the Butte STP, ranged from 3.3 to 11.5 between October 19
and 21 [Figure 7]. These extremes were only recorded one time each
during the period of the survey (October 16 to 23, 1978) and it is not
known whether these fluctuations occur periodically or resulted from a
short-term malfunction of the pH control (acid injection) system at the
Anaconda Company's outfall. In any event, if the range of pH fluctua-
tions observed during the survey is characteristic of events which occur
from time to time in the headwaters of Silver Bow Creek, it is not
-likely that aquatic life of any significance can be established or
survive.
-------
NOTE: RECORDER CHART SPEED VARIED WITH BATTERY STRENGTH
ro
Figure 7. Record of pH from Silver Bow Creek Station SO, 10/19/78 to 10/21/78
-------
27
Although the metals load in the Creek clearly increases downstream
between Butte and Gregson [Figures 3, 4 and 5), it appears that the
sharpest increase occurs in the reach between Sampling Stations 87 and
88 where there are no significant point source discharges. This reach
has the largest single mass of alluvial tailings deposits in the study
reach, and these deposits are not only the most extensive areally but
are also thicker than in the other sampled locations.
Based on analyses of three grab samples collected during the sur-
vey, the Butte STP (Station 81) contributes more zinc but less than one
quarter as much copper to Silver Bow Creek as is in the main stem just
upstream of the STP. Montgomery^ suggested that the Butte sewerage
system may serve as a collector system for groundwater, thus accounting
,for the relatively high dissolved metals content. During the survey, a
shallow groundwater pumping program was in operation at the STP for
dewatering purposes during sewage plant construction and modernization.
The discharge from this operation contained about 0.1 mg/1 copper, 30
mg/1 zinc and a trace of cadmium. Although the condition of the sewage
collection system and its relationship to the water table in Butte is
not known, the chemistry of the groundwater supports Montgomery's sug-
gestion. Montgomery^ further indicated that, as far as is known by the
Region, there are no significant industrial connections to the sewerage
system although service stations or small unidentified operators may
discharge some waste to the system.
During the October 1978 survey, an oily substance of unknown origin
was observed discharging into the Creek through its bed and left bank
along an approximately one hundred yard reach in the vicinity of Station
Number 80 at the old wooden bridge south of the Butte STP. Even though
the streams velocity was about one foot per second in this reach enough
oil was percolating into the stream to make a clearly observable sheen.
Region VIII personnel sampled this oily substance for analysis in their
laboratory.^
-------
28
GROUNDWATER QUALITY
The groundwater quality data [Table 3] show high concentrations
of copper and zinc from auger holes in the Colorado Tailings Pile at
the west edge of Butte and in the large tailings deposits in the vicinity
of Ramsay. The low pH values of these samples (3.0 to 5.5) are charac-
teristic of aquatic environments in which leaching is facilitated, dis-
solved ions stay in solution and will move through groundwater flow
systems to points of discharge such as occur along, the channel of Silver
Bow Creek. If the natural groundwater throughout the study area has as
high a metals content as that observed at the groundwater drain asso-
ciated with the Butte STP construction, there will be continuing metals
contributions to the creek regardless of any reclamation efforts in-
volving removal of the tailings.
TAILINGS VOLUME AND COMPOSITION
The high degree of heterogeneity, wide-spread distribution and
highly differing thicknesses of the tailings deposits prohibit an
accurate quantitative calculation of the metals content of tailings in
the entire study reach of Silver Bow Creek. However, there are esti-
6 3 6 3
mated to be approximately 1.7x10 m (2.3x10 yd ) of old mine tailings
distributed along the flood plain of Silver Bow Creek between Butte and
Gregson, Montana. Tailings volumes were estimated from approximate
areas determined from aerial photographs and topographic maps and
average thicknesses were estimated from hand auger holes. The Colorado
Tailings Deposit has an area of about 140xl03m2 (166xl03yd2) and a thick-
ness of about 1.5 m (5 ft) giving a volume of about 213xl03m3 (278xl03
yd ). The extensive deposits in the vicinity of Ramsay cover an area of
about 735xl03m2 (880xl03yd2) to a depth estimated to average 1.8 m (6
ft) giving a volume of about 1.35xl0^m3 (1.8xl0^yd3). Another deposit
O O
in the vicinity of Miles Crossing is estimated to cover about 84x10 m
3 2
(110x10 yd ) to a depth of about 1 m (3 ft) giving a volume of about
-------
Table 3
METALS ANALYSFS OF TAILINGS AND GROUNDWATER SAMPLES
{SILVER BOW CREEK BETWEEN BUTTE AND GREGSON, MONTANA)
Groundwater Samples mq/1
Hole and Sample
Pb
Zn
Ag
Cu
As
Ag
Cd
Cu Fe
Hga
Pb
Zn
pH
Groundwater
Station No.
Colo. Tailings Rouse #6
100-01 59"
1,300
11,000
110
1,400
4.4
ND
0.17
0.27 97
ND
ND
100
4.9
#91-010
Colo. Tailings N.W.
101-01 23"
102-01 50"
470
530 ¦
3,700
12,000
13
79
500
3,900
n
ND
0.67
130 190
ND
1.1
210
3.0
#95-01D
E. Ramsey
106-01 30"
107-01 75"
108-01 110"
560
ND
ND
2,100
460
1,200
29
NO
ND
650
69
87
0.03
ND
4.4
33C 1.9
0.0006
ND
1,100
4.3
#93-01D
Ramsey S.W.
110-01 33-48"
111-01 90"
112-01 120"
590
NO
100
500
820
690
ND
ND
ND
320
1,000
880
ND
ND
0.27
37 ND
ND
ND
81
5.5
#94-010
Ramsey S.E.
104-01 18"
105-01 30"
1,800
1,900
4,400
5,500
94
34
4,900
5,400
Dry Hole
Miles Crossing
109-01 20"
13,000
22,000
66
20,000
Dry Hole
Wood Pipe
103-01
3,000
6,300
55
2,600
ND
NO
ND
ND 0.21
ND
ND
ND
6.8
#92-010
a For mercury - detection
limit are considered Not
D = dissolved
limit = 0.0001 mg/1.
. Detected (NO).
All values
less than five
tiroes
the detection
ro
to
-------
30
84x10 m (110x10 yd ). Additional small strings of tailings through-
3 3
out the study reach may, in aggregate, constitute another 153x10 m
3 3
(200x10 yd ). Thicknesses of these deposits range from less than 0.3
m (1 ft) to as much as 1 m (3 ft).
The tailings samples [Table 3] show a wide range in metals con-
tent. Based on an earlier study, high concentrations of copper and
zinc were expected. The Interim Report^ contains analyses of tailings
from three auger holes in the extensive deposits in the vicinity of
Ramsay. The reported values for copper range from 50 mg/kg to 4,300
mg/kg (average 2,167 mg/kg). For zinc, the range is from 160 mg/kg to
11,300 mg/kg (average 4,263 mg/kg).
During the current study, tailings samples were collected from
seven auger holes at locations from the west side of Butte (Colorado
Tailings Deposit) to the vicinity of Miles Crossing [see Table 3]. In
these holes, copper concentrations ranged from 69 mg/kg to 20,000 mg/kg
(average 2,675 mg/kg) and zinc ranged from 460 mg/kg to 22,000 mg/kg
(average 5,436 mg/kg). Using conservative values of 2.7 specific
gravity, 10% porosity, 0.2% copper and 0.4% zinc, it is estimated that
there are about 9.9x10^ kg (20xl0^1b) of copper and 18xl0^kg (39x10^1b)
of zinc in the tailings deposits adjacent to Silver Bow Creek in the
study reach.
STREAM REHABILITATION
There are several important items to be evaluated when considering
removal and possible re-refining of tailings along the Creek as an aid
to minimizing the pollution of Silver Bow Creek. Several miles of the
railroad bed between Butte and Anaconda have been built of tailings.
Thus, any effort to thoroughly remove all tailings would require relo-
cation or temporary disruption of rail transport along this route.
-------
31
Dredging of the tailings would create high turbidity in the Creek for
prolonged periods and might cause deleterious effects downstream. Many
of the tailings are saturated with shallow groundwater of low pH and
high dissolved metals content. The sudden release of this contaminated
water to the Creek could also have serious effects on the reestablished
downstream aquatic life.
The installation of a clay seal and soil cover over the tailings
has been discussed as a possible means of stabilizing and reducing
leachate through the tailings. Such a scheme would reduce local infil-
tration and some leaching. However, because the tailings are deposited
in the flood plain of the Creek, which constitutes a groundwater dis-
charge area, much of the volume of tailings will remain saturated and
will continue to leach into the Creek through natural groundwater dis-
charge. In addition, the shallow groundwater occurrence in these flood
plain deposits will continue to facilitate the upward percolation of
groundwater through capillary movement and evaporation to concentrate
metal salts on the land surface. As subsequent precipitation and runoff
events occur, this material will be eroded into the Creek channel.
Thus, stabilization probably would not result in any long-term reduction
in the metals load being contributed to and transported by the stream.
This investigation has made it evident that attempts to control
metals infiltration to the Creek from the adjacent tailings deposits
would be of questionable benefit.
Discharge of ammonia and residual chlorine from the Butte STP may
cause deleterious effects on the quality of the Creek.
Improved control of the point source discharges (Anaconda Co. and
the Butte STP) will stabilize the quality of water in Silver Bow Creek.
Subsequent monitoring of the physical, chemical and biological quality
of the Creek will provide a basis for determining whether any further
remedial actions are desirable.
-------
REFERENCES
1. National Enforcement Investigations Center, Interim Report -
Geohydrological Evaluation of Silver Bow Creek and its Flood
Plain, Butte, Montana Area: U.S.E.P.A. - NEIC, Denver, CO.,
Feb. 1977.
2. Environmental Protection Agency, A Water Quality Study of the
Upper Clark Fork River and Selected Tributaries: U.S.E.P.A.
Region VIII, Denver, CO., Sept. 1972
3. Spindler, The Clean-up of Silver Bow Creek: Env. Eng., Anaconda
Co., Butte Operations, Butte, MT., 1976.
4. Montana Fish and Game Department, Western Montana Fishery Inves-
tigations: Fish Management Surveys. Project No. F-12-9-20, Job
No. 1-b (Segment 2). Fisheries Division, July 1, 1973 - June 30,
1975.
5. Botz, M.K., Hydrogeology of the Upper Silver Bow Creek Drainage
Area, Montana: Mont. Bu. of Mines and Geo!., Bull. 75, 1969.
6. Montgomery, R., personal communication, 1979.
-------
APPENDIX A
STATION DESCRIPTIONS
-------
APPENDIX A
STATION DESCRIPTIONS
SO, Silver Bow Creek 55 meters (180 ft) upstream of old wooden bridge
south of Butte STP, - downstream of Anaconda Co. discharge.
81, City of Butte STP outfall to Silver Bow Creek at southwest side of
Butte STP.
82, Groundwater drain; blue flexible tubing, from Butte STP construction
site adjacent to Butte STP outfall to Silver Bow Creek.
83, Butte storm drain at Centennial Ave. culvert about 360 meters (400
yds) east of the Butte STP.
84, Silver Bow Creek about 83 meters (275 ft), upstream of bridge at
Alloy Siding.
85, Seep below Stauffer Chemical Plant at confluence with Silver Bow Creek.
86, Rectangular orifice of outfall structure about 1.6 kilometers (.1
mile) east of Ramsay, flowing into north side of Silver Bow Creek about
180 meters (200 yds) upstream of Ramsay East RR bridge.
87, Silver Bow Creek, about 30 meters (100 ft) upstream of Ramsay
East RR bridge. Sampling site was moved about 135 meters (150 yds)
downstream to provide adequate mixing of Creek flow with flow from 86
when discharging.
88, Silver Bow Creek 180 meters (200 yds) downstream of Miles Crossing
below confluence of two meandering channels of the creek, south side of
railroad.
-------
89, Silver Bow Creek 9 meters (30 ft) downstream from Gregson/ Fairmont
Hot Springs road bridge.
91, Old Rouse Auger Hole No. 6, near east end of Colorado tailings pile,
west of Butte adjacent to Silver Bow Creek.
92, Wooden pipe groundwater drain into Silver Bow Creek on north side
about 55 meters (60 yds) downstream of bridge crossing at Silver Bow.
93, Ramsay east groundwater from old Rouse Auger Hole No. 1.
94, Ramsay southwest about 260 meters (290 yds) south of RR and about 75
meters (83 yds) north of confluence of Sand Creek with Silver Bow Creek.
95, Colorado Tailings Pile near northwest edge, adjacent to Silver Bow
Creek - groundwater from auger hole.
96, Brov/ns Gulch at Interstate 90, south end of culvert under highway.
100, Colorado Tailings Pile, 9 meters (30 ft) west of old Rouse No. 6
Auger Hole - depth 120 cm (48 in) - augered tailings sample.
101, Colorado Tailings Pile, northwest adjacent to Silver Bow Creek -
depth 60 cm (24 in) augered tailings sample.
102, Colorado Tailings Pile, northwest adjacent to Silver Bow Creek -
depth 125 cm (50 in) augered tailings sample.
103, North side of Silver Bow Creek about 135 meters (150 yds) below
Silver Bow bridge crossing - depth 45 cm (18 in) augered tailings sample.
-------
104, Tailings - Ramsay southeast - south of.rail road and Silver Bow
Creek about 45 meters (50 yds) south of Creek - depth 45 cm (13 in)
auguered tailings sample.
105, Tailings - Ramsay southeast - south of railroad and Silver Bow
Creek about 45 meters (50 yds) south of Creek - depth 75 cm (30 in)
augered tailings sample.
105, East Ramsay tailings deposits, about 4.5 meters (15 ft) west of old
Rouse No. 1 - depth 75 cm (30 in) augered tailings sample.
107, East Ramsay tailings deposits, about 4.5 meters (15 ft) west of old
Rouse Mo. 1 - depth 187 cm (75 in) augered tailings sample.
108, East Ramsay tailings deposits about 4.5 meters (15 ft) west of old
Rouse Mo. 1 - depth 275 cm (110 in) augered tailings sample.
109,.About 475 meters (520 yds) upstream of M.iles Crossing at Railroad
bridge - depth 50 cm (20 in) augered tailings sample.
110, Ramsay southwest about 260 meters (290 yds) south of railroad and
75 meters (250 ft) north of confluence of Sand Creek with Silver Bow
Creek - depth composite 82.5 cm to 120 cm (33 in to 48 in) augered
tailings sample.
111, Ramsay southwest about 260 meters (290 yds) south of railroad and
75 meters (250 ft) north of confluence of Sand Creek with Silver Bow
Creek - depth 2.3 meters (7.5 ft) augered tailings sample.
112, Ramsay southwest about 260 meters (290 yds) south of railroad and
75 meters (250 ft) north of confluence of Sand Creek with Silver Bow
Creek - depth 9.1 meters (10 ft) auguered tailings sample.
-------
APPENDIX B
CHEMICAL ANALYSES
-------
APPENDIX B
SURFACE WATER, GROUNDWATER AND TAILINGS ANALYTICAL DATA
SILVER BOW CREEK VALLEY BETWEEN BUTTE AND GREGSON, MONTANA
October 1978
Water Samples
Sta.
No.
Station Description
As
Ag
Be
Cd
Cu
(lag/1)
Ft!
Hg Pb
Zn
CI"
S04"
80 03
SBC Upstream of Wooden Bridge
NO
ND
0.12
0.99
ND
0.41
11
600
80 030
II
II
II II II
NO
-
ND
ND
-
-
0.24
80 04
II
II
(1 II II
NO
.
_
ND
0.42
3.2
ND
0.73
10
830
80 04D
II
II
II II II
ND
-
ND
ND
-
-
0.05
80 05
II
II
II II II
ND
.
_
ND
0.19
1.5
ND
0.58
9
720
80 05D
II
It
If (1 II
ND
-
-
ND
0.05
-
-
0.30
81 02
Butte STP
ND
_
_
ND
0.17
1.6
ND
2.3
20
70
81 02D
tl
tl
ND
-
ND
0.11
-
-
2.0
81 03
II
II
ND
-
_
ND
0.27
6.4
ND
2.2
19
50
81 03D
II
II
ND
-
-
ND
0.08
-
-
1.4
81 04
II
II
ND
_
NO
0.11
0.26
ND
1.7
22
100
81 04D
II
It
ND
-
-
ND
0.12
-
-
1.9
82 02
Groundwater Drain at STP
ND
0.09
0.11
0.99
ND
33
32
680
82 020
M
II II II
ND
-
0.09
0.11
-
-
34
8203
II
II II It
ND
-
-
0.08
0.08
0.99
ND
27
27
530
82 03D
II
II II II
ND
-
0.08
0.11
-
-
27
82 04
II
II II II
ND
.
.
0.08
0.10
0.94
ND
27
28
570
82 040
II
tl II II
ND
-
0.08
0.12
-
-
27
83 02
Butte Storm Drain
ND
•
•
ND
2.4
2.6
ND
9.6
22
220
83 02D
II
II
II
NO
-
ND
0.37
-
-
7.5
83 03
II
II
II
ND
-
-
ND
1.6
1.1
ND
9.0
22
210
83 03D
II
tl
II
ND
•
-
ND
0.93
-
-
7.5
83 04
II
II
II
ND
•
_
ND
2.2
0.26
ND
12.
25
270
83 04D
II
II
II
ND
-
-
ND
0.41
-
-
9.0
84 02
SBC
Alloy
Siding
ND
-
-
ND
0.27
1.6
ND
1.1
15
440
84 02D
II
it
n
ND
-
ND
0.08
-
-
0.30
84 03
II
ii
ii
ND
-
ND
0.20
1.1
ND
0.94
14
520
84 03D
II
ii
ii
ND
-
-
ND
0.10
-
-
0.94
84 04
II
n
n
ND
_
_
ND
0.23
1.5
ND
1.2
15
720
84 040
II
H
ii
ND
-
-
ND
0.10
-
-
0.88
-------
APPENDIX B (Cont.)
SURFACE WATER, GROUNDWATER AND TAILINGS ANALYTICAL DATA
SILVER BOW CREEK VALLEY BETWEEN BUTTE AND GREGSON, MONTANA
October 1978
Water Samples
Sta.
No.
Station Description
As
Ag
Be
Cd
«-
Cu
(ntg/l)
Fe
Hg
Pb
Zn
CI"
so;
85 OlD Sand Creek (Stauffer)
ND
ND
ND
ND
ND
-
-
ND
ND
150
1,100
£6 01
£6 OlD
Rectangular Orifice Nr E. Ramsay Site
II II 11 II II 11
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
NO
NO
ND
ND
1
10
86 02
86 020
II II II II II II
II II II II II II
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
0.23
ND
ND
NO
ND
ND
1
10
87 02
87 02D
SBC - E. Ramsay near RR Bridge
II II II II II
ND
ND
-
-
ND
ND
0.20
0.05
1.3
ND
-
1.2
1.1
10
340
87 03
87 03D
II II II II II
II *1 II II II
ND
NO
-
-
ND
ND
0.19
0.05
1.2
ND
-
0.94
0.73
10
340
87 04
87 04D
II II II II II
II II II II II
ND
ND
-
-
ND
ND
0.21
0.05
1.4
ND
-
1.0
0.64
10
440
88 02
88 02D
SBC - Miles Crossing
II il 11
ND
ND
-
-
ND
ND
0.27
0.08
1.6
ND
-
1.5
0.99
14
360
88 03
88 03
II 11 II
II II II
ND
NO
-
-
ND
ND
0.23
0.05
1.4
ND
-
1.2
0.70
11
330
88 04
88 04 D
II II 11
II ll ll
ND
ND
-
-
ND
ND
0.31
0.05
1.9
ND
-
1.3
0.72
11
370
89 02
89 02D
SBC at Gregson Bridge
II II ll ll
ND
ND
-
-
ND
ND
0.22
0.09
1.2
ND
-
0.74
0.36
8
210
89 03
89 030
II II ll II
11 II ll II
ND
ND
-
-
ND
ND
0.24
0.07
1.4
ND
-
0.82
0.34
10
260
89 04
89 040
ll II II II
II II II ll
ND
ND
-
-
ND
ND
0.36
0.07
1.9
ND
-
1.3
0.57
13
360
96 OlD
Brown's Gulch at 1-90
0.03
ND
ND
ND
ND
ND
-
ND
0.05
8
440
91 OlD
GW Colo. Tailings - Rouse #6
4.4
ND
ND
0.17
0.27
97
-
ND
100
-
-
92 OlD GW Wood Pipe Drain - Silver Bow
ND
ND
ND
ND
ND
0.21
-
ND
ND
-
93 OlD
E. Ramsay - Rouse #1
0.03
ND
ND
4.4
330
1.9
-
ND
1,100
-
-
94 OlD Ramsay - S.W.
ND
ND
ND
0.27
37
ND
-
ND
81
15
470
95 OlD
Colo. Tai'iings N.W.
11
ND
ND
0.67
130
190
-
1.1
210
-
-
-------
APPENDIX B (Cont.)
SURFACE WATER, GROUNDWATER AND TAILINGS ANALYTICAL DATA
SILVER BOW CREEK VALLEY BETWEEN BUTTE AND GREGSON, MONTANA
October 1978
Water Samples
Sta.
No.
Station Description
As
Ag
Be
Cd Cu Fe
Hg Pb
Zn
«- Mg/g
-~
10 001
Colo. Tailings - Rouse #6
59"
-
110
-
1,400
1,300
11,000
10 101
Colo. Tai1ings N.W.
25"
-
13
-
500
470
3700
10 201
Colo. Tailings N.W.
50"
-
79
-
3,900
530
12,000
10 301
Wood Pipe GW drain
18"
-
55
-
2,500
3,000
6,300
10 401
Ramsay - SE
18"
-
95
-
4,900
1,800
4,400
10 501
Ramsay - SE
30"
-
34
-
5,400
1,900
5,500
10 601
E. Ramsay - Rouse ft 1
30"
-
29
-
650
560
2,100
10 701
H II
75"
-
ND
-
69
I
ND
460
10 801
II „ 110"
-
ND
-
87
ND
1,200
10 901
Upstream - Miles Crossing
20"
-
66
-
20,000
- 13,000
22,000
11 001
Ramsay S.W. 33" -
48"
-
ND
-
320
590
500
11 101
11 li
90"
-
ND
-
1,000
ND
820
11 201
" " 120"
.
ND .
-
880
100
690
-------
APPENDIX C
ANALYTICAL METHODOLOGY
Silver Bow Creek, Montana
-------
METHODOLOGY
Water and sediment were analyzed for the following parameters;
Ag, As, Be, Cd, Cu, Fe, Hg, Pb, Zn, sulfate and chloride. Approved
methods for NPDES monitoring, (40 CFR 136, Federal Register, Dec. 1,
1976), were used in the analysis of all water samples. The sediment
samples (mine tailings) were analyzed for Ag, Pb, Cu and Zn. The sam-
ple preparation technique used for the mine tailings was based on that
described in the Chemistry Laboratory Manual - Bottom Sediments of the
Great Lakes Region Committee on Analytical Methods, 1969. The references
to the methods used in the analysis of each parameter and its detection
limit in ing/1 are listed in Table I for the water samples. The references
to the methods used in the analysis of each metal and its detection limit
in ug/g are listed in Table II for the mine tailings samples. The de-
tection limits in Table II assume a one gram dry weight of sediment and
a 100 ml digestion volume.
The methods listed in Tables I and II were followed closely with
no significant deviations from the approved methods. As an added pre-
caution, all analyses with the exception of mercury, were performed
using background correction procedures in order to preclude extraneous
signals from the sample matrix.
Quality Control
. The replicate sample results for each parameter are listed in
Table III. The relative percent difference (RPD) between the sample
analysis and the replicate sample analysis is shown for each determina-
tion. The number of replicates analyzed for each element is directly
proportional to the number of analyses requested for each element.
-------
In some cases, the RPD is rather high (e.g. mercury). However, in
these cases the difference between the sample and replicate concen-
trations is always near the detection limit shown for each parameter
[Table I].
The spiked sample results for each parameter are shown in Table IV.
The average percent recovery is within acceptable limits (100 + 10%) in
all cases.
The EPA reference sample results for all metals and inorganic
parameters are listed in terms of RPD in Table V. The results for
all metals and inorganic parameters are all within acceptable limits,
(+ 10% RPD).
-------
Table I. Analytical Methods and Detection
Limits - Water Samples
Parameter
Technique
Detection
Reference^
Limit, mg/1
Ag.
Flame Atomic Absorption
0.02
A, p. 146
As
Flameless Atomic Absorption
0.005
B
Be
Flame Atomic Absorption
0.02
A, p. 99
Cd
Flame Atomic Absorption
0.02
A, p. 101
Cu
Flame Atomic Absorption
0.01
A, p. 108
Fe
Flame Atomic Absorption
0.04
A, p. 110
Hg
Flameless Atomic Absorption
0.0001
A, p. 118
Pb
Flame Atomic Absorption
0.1
A, p. 112
Zn
Flame Atomic Absorption
0.001
A, p. 155
CI"
Titration, Hg(N03)2
0.3
C, p. 304
s04~
Turbidimetry
1.6
C, p. 496
1 A = Methods for Chemical Analysis of Water and Wastes, U.S. Environ-
mental Protection Agency, (1974).
B = Atomic Absorption Newsletter, 1_4, 109. (1975).
C = Standard Methods for the Examination of Water and Wastewater,
14th ed., APHA - AWWA - WPGF, (1975).
-------
Table II. Analytical Methods and Detection
Limits - Mine Tailings Samples
Parameter Technique Detection Reference^
Limit, ug/g
Ag
Flame Atomic Absorption
2
A
B,
P-
146
Cu
Flame Atomic Absorption
1
A
B,
P-
108
Pb
Flame Atomic Absorption
10
A
B,
P-
112
Zn
Flame Atomic Absorption
1
A
B,
P-
155
1 A = Chemistry Laboratory Manual - Bottom Sediments, Great Lakes
Region Committee on Analytical Methods, U.S. EPA, Federal
Water Quality Administration, (December 1969).
B = Methods for Chemical Analysis of Water and Wastes. U.S. EPA
(1974).
-------
Table III. Replicate Sample Results
Parameter
Sample
Analysis
mg/1
Replicate
Analysis
mg/1
RPD, %
Ag
ND
ND
-
As
0.010
0.010
0
0.014
0.011
24
0.011
0.012
9
0.009
0.008
12
Be
ND
ND
-
Cd
0.02
0.03
40
0.04
0.03
29
ND
ND
-
ND
ND
-
0.27
0.25
8
Cu
1.6
1.6
0
0.41
0.45
9
0.27
0 27
0
0.27
0.27
0
45
45
0
Fe
o.n
0.08
32
1.6
1.5
6
1.1
0.96
14
1.6
1.6
0
0.14
0.18
25
Hg
0.00011
0.00011
0
ND
ND-
-
0.00014
0.00005
95
Pb
ND
ND
-
Zn
9.0
9.6
6
9.0
9.1
0.5
1.1
1.1
0
1.5
1.5
0
81
80
1
so4=
210
210
0
1,100
1,100
0
340
340
0
cr
15
15
0
13
13
0
22
22
0
RPD = Relative Percent Difference = the difference between the sample
and replicate result divided by the average of the sample plus
replicate result.
ND = Mot Detectable
-------
Table IV. Spiked Sample Results
Parameter
N
Average % Recovery
Ag
1
100
As
5
100
Be
1
94
Cd
4
105
Cu
4
99
Fe
4
97
Hg
4
105
Pb
.1
90
Zn
4
100
cr
3
95
S04~2
3
101
N = total number of spiked samples analyzed.
-------
Table V. EPA Quality Control Sample Results
Parameter
True Value
Experimental
RPD, %
mg/1
Value, mg/1
Ag*
0.788
0.785
0.4
As
0.109
0.111
2
Be
0.398
0.390
2
Cd
0.073
0.070
4
Cu
0.102
0.105
3
Fe
0.678
0.700
3
Hg
0.00080
0.00081
1
Pb
0.352
. 0.350
1
Zn
0.174
0.178
2
CI"
28.1
28.2
0.4
so4 =
12
11.5
4
* An AQC sample was prepared fn the laboratory using reagent grade
AgH03.
e-7
------- |