U.S. Department of the Interior

U.S. Geological Survey

Scientific Investigations Report 2007–5265

Prepared in Cooperation with the U.S. Environmental Protection Agency

Hydrogeochemical Investigation of the Standard Mine 

Vicinity, Upper Elk Creek Basin, Colorado

Hydrogeochemical Investigation of the 

Standard Mine Vicinity, Upper Elk Creek 

Basin, Colorado

By Andrew H. Manning, Philip L. Verplanck, M. Alisa Mast, and Richard B. Wanty

Prepared in Cooperation with the U.S. Environmental Protection Agency

Scientific Investigations Report 2007–5265

U.S. Department of the Interior

U.S. Geological Survey
U.S. Department of the Interior

DIRK KEMPTHORNE, Secretary

U.S. Geological Survey

Mark D. Myers, Director

U.S. Geological Survey, Reston, Virginia: 2008

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Suggested citation:

Manning, A.H., Verplanck, P.L., Mast, M.A., and Wanty, R.B., 2008, Hydrogeochemical investigation of the 

Standard Mine vicinity, upper Elk Creek Basin, Colorado: U.S. Geological Survey Scientific Investigations 

Report 2007–5265, 131 p.

About this Product

For more information concerning this publication, contact:

Team Chief Scientist, USGS Central Region Earth Surface Processes Team

Box 25046

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Denver, CO 80225-0046

(303) 236-5344

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Publishing support provided by:

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Manuscript approved for publication November 27, 2007

Edited by Mary-Margaret Coates, Contractor, ATA Services

Graphics by Andrew H. Manning and layout by Sharon Powers
iii

Contents

Abstract...........................................................................................................................................................1

Introduction ....................................................................................................................................................2

Site Description..............................................................................................................................................2

Location and Climate............................................................................................................................2

Geology...................................................................................................................................................2

Mining Activities ...................................................................................................................................6

Previous Hydrogeologic Studies.................................................................................................................7

Acknowledgments.........................................................................................................................................7

Methods...........................................................................................................................................................7

Study Approach.....................................................................................................................................7

Description of Methods .......................................................................................................................9

Major Ion and Trace Element Chemistry..................................................................................9

Strontium Isotopes ......................................................................................................................9

Deuterium and Oxygen-18 .........................................................................................................9

Ground-Water Age Dating........................................................................................................10

Sample Collection and Analysis.......................................................................................................11

Major Ion and Trace Element Chemistry................................................................................11

Strontium Isotopes ....................................................................................................................11

Deuterium and Oxygen-18 .......................................................................................................13

Tritium. .........................................................................................................................................13

Dissolved Gases.........................................................................................................................13

Carbon Isotopes.........................................................................................................................13

Quality Assurance and Quality Control ...........................................................................................14

Results. ...........................................................................................................................................................14

Survey of Ground-Water Discharge Locations and Sample Site Selection .............................14

Underground Observations and Sample Site Selection ..............................................................18

Field Parameters.................................................................................................................................20

Task 1. .........................................................................................................................................20

Task 2. .........................................................................................................................................22

Task 3. .........................................................................................................................................22

Major Ion and Trace Element Chemistry.........................................................................................22

Task 1. .........................................................................................................................................27

Task 2. .........................................................................................................................................29

Task 3. .........................................................................................................................................29

Strontium Isotopes..............................................................................................................................40

Deuterium and Oxygen-18 ................................................................................................................40

Task 1. .........................................................................................................................................42

Task 3. .........................................................................................................................................42

Tritium and Noble Gases....................................................................................................................49

Task 2. .........................................................................................................................................49

Task 3. .........................................................................................................................................53

Carbon-14.............................................................................................................................................53
iv

Discussion.....................................................................................................................................................53

Distribution of Ground-Water Discharge and Potential Geologic Controls on Flow ..............53

Ground-Water Residence Times ......................................................................................................57

Controls on Ground-Water Chemistry .............................................................................................60

Controls on Metal Concentrations..........................................................................................60

Controls on Major Ion Chemistry ............................................................................................60

Controls on Standard Mine Water Chemistry .......................................................................61

Controls on Elk Creek Water Chemistry .................................................................................62

Conclusions...................................................................................................................................................63

References....................................................................................................................................................64

Appendix 1. Sampling and Analysis Plan................................................................................................67

Appendix 2. Sampling Information and Field Parameters....................................................................85

Appendix 3. Concentrations of Major Ions and Selected Metals.......................................................95

Appendix 4. Results of ICP–MS Analyses ............................................................................................115

Figures

1. Index map showing location of Standard Mine, Colorado ....................................................3

2. Topograghic map showing location of three sample areas in Standard 

 Mine vicinity ..................................................................................................................................4

3. Geologic map of Standard Mine vicinity...................................................................................5

4. Cross section of Standard Mine.................................................................................................8

5. Aerial photograph showing location of aboveground samples sites within 

 the three sample areas shown in figure 2 ..............................................................................15

6. Cross section showing location of underground samples sites in Level 3 of 

 Standard Mine.............................................................................................................................16

7. Cross section showing location of underground samples sites in Level 5 

 of Standard Mine ........................................................................................................................17

8. Geologic map showing location of aboveground sample sites..........................................19

9. Diagrams showing field parameters at task 1 sample sites................................................21

10. Aerial photograph showing pH at aboveground sample sites............................................23

11. Aerial photograph showing specific conductance at aboveground sample sites..........24

12. Cross section showing field parameters at underground sample sites in 

 Level 3 of Standard Mine...........................................................................................................25

13. Cross section showing field parameters at underground sample sites in 

 Level 5 of Standard Mine...........................................................................................................26

14–17. Diagrams showing:

 14. Field parameters versus overburden thickness in underground samples.................27

 15. Comparison of analytical results by using ICP–AES and ICP–MS for barium, 

 manganese, and strontium concentrations ................................................................... 28
v

 16. Calcium and sulfate ion concentrations at task 1 sample sites ..................................29

 17. Concentrations of zinc, lead, cadmium, copper, and manganese at 

 task 1 samples sites ............................................................................................................30 

18–24. Aerial photographs annotated to show concentrations at aboveground

 sample sites of the following metals:

 18. Calcium..................................................................................................................................31

 19. Sulfate ...................................................................................................................................32

 20. Zinc ........................................................................................................................................33

 21. Lead .......................................................................................................................................34

 22. Cadmium ...............................................................................................................................35

 23. Copper...................................................................................................................................36

 24. Manganese...........................................................................................................................37

25. Cross section showing concentrations of calcium, sulfate, and selected 

 metals at underground sample sites in Level 3 of Standard Mine.....................................38

26. Cross section showing concentrations of calcium, sulfate, and selected metals at 

underground sample sites in Level 5 of the Standard Mine................................................39

27. Diagrams showing concentration of calcium and sulfate versus 

 overburden thickness in underground samples....................................................................40

28. Diagrams showing concentrations of zinc, lead, cadmium, copper, and 

 manganese versus overburden thickness in underground samples.................................41

29. Aerial photograph annotated to show strontium concentration at 

 aboveground sample sites ........................................................................................................43

30. Aerial photograph annotated to show strontium isotope ratios (87Sr/86Sr) 

 at aboveground sample sites....................................................................................................44

31. Diagram showing strontium concentration versus strontium isotope ratio (87Sr/86Sr)....45

32. Diagrams showing δ18O and δ2H concentration at task 1 sample sites.............................45

33. Cross section showing δ18O and δ2H concentration at underground 

 sample sites in Level 3 of Standard Mine...............................................................................47

34. Cross section showing δ18O and δ2H concentration at underground

 samples sites in Level 5 of Standard Mine.............................................................................48

35. Diagrams showing δ18O and δ2H concentrations versus overburden thickness

 for underground samples. .........................................................................................................49

36. Aerial photograph annotated to show tritium concentration at aboveground 

 sample sites.................................................................................................................................52

37. Aerial photograph annotated to show apparent 3H/3He age at 

 aboveground sample sites ........................................................................................................54

38. Cross section showing tritium concentration at underground sample sites in 

 Level 3 of Standard Mine...........................................................................................................55

39. Cross section showing tritium concentration and apparent 3H/3He age at 

 underground sample sites in Level 5 of Standard Mine.......................................................56
vi

40–45. Diagrams showing:

 40. Tritium concentration versus overburden thickness for underground

 samples .................................................................................................................................57

 41. Precipitation 3H records for Salt Lake City, Utah, and Albuquerque, N. Mex............58

 42. Initial 3H concentration of samples (measured 3H + measured 3Hetrit) 

 versus apparent 3H/3He age...............................................................................................59

 43. Quarterly precipitation 3H concentration for Albuquerque, N. Mex., 1997–2002......59

 44. Zinc concentration versus cadmium concentration .....................................................61

 45. Sulfate concentration versus zinc concentration..........................................................62

Tables

1. Methods of analysis and detection limits...............................................................................12

2. Strontium isotope content of selected water samples ........................................................42

3. Oxygen-18, deuterium, and carbon isotope content of selected water samples............46

4. Dissolved gas and 3H data and 3H/3He ages of samples ......................................................50
vii

Abbreviations Used in This Report

Units of measure Initialisms and other terms

mL microliter, microliters AMS accelerator mass spectrometry

mm micrometer, micrometers ICP–AES inductively coupled plasma–atomic emission

mS/cm microsiemens per centimeter ICP–MS inductively coupled plasma–mass 

spectrometry

cfs cubic feet per second IR–MS isotope ratio–mass spectrometry

cm3STP/g cubic centimeters (of gas) at standard 

temperature and pressure per gram of 

water

MC–ICP–MS multicollector inductively coupled plasma 

mass spectrometer

Eh redox potential TU tritium unit; 1 TU = 1 atom of 3H per 1,018 

atoms of hydrogen

ft foot, feet U.S. United States

gpm gallons per minute inby on the tunnel-end side of

h hour, hours outby on the portal side of

in./yr inch (inches) per year

Ma mega-annum; millions of years ago

mg/L milligram (milligrams) per liter

mg/s milligram (milligrams) per second

mi mile, miles

pH measure of concentration of hydrogen 

ions

yr year, years
viii

Conversion Factors, Abbreviations, and Datums

Inch/Pound to SI

Multiply By To obtain

Length

inch (in.) 25.4 centimeter (cm))

foot (ft) 0.3048 meter (m) 

mile (mi) 1.609 kilometer (km)

Area

square meter (m2) 2.590 square kilometer (km2) 

Flow rate

gallon per minute (gal/min) 0.06309 liter per second (L/s)

Pressure

atmosphere, standard (atm) 101.3 kilopascal (kPa)

SI to Inch/Pound

Multiply By To obtain

Length

centimeter (cm) 0.3937 inch (in.)

meter (m) 3.281 foot (ft)

Volume

liter (L) 33.82 ounce, fluid (fl. oz)

cubic centimeter (cm3) 0.06102 cubic inch (in3)

Mass

gram (g) 0.03527 ounce (oz)

Temperature in degrees Celsius (°C) may be converted to degrees Fahrenheit (°F) as follows:

 °F=(1.8×°C)+32

Temperature in degrees Fahrenheit (°F) may be converted to degrees Celsius (°C) as follows:

 °C=(°F-32)/1.8

Vertical coordinate information is referenced to the North American Vertical Datum of 1988 

(NAVD 88).

Horizontal coordinate information is referenced to the North American Datum of 1983 (NAD 83).

Altitude, as used in this report, refers to distance above the vertical datum.
Abstract

Ground- and surface-water samples were collected in 

the vicinity of the Standard Mine in west-central Colorado 

in order to characterize the local ground-water flow system, 

determine metal concentrations in local ground water, and 

better understand factors controlling the discharge of metalrich waters from the mine. The sampling program included a 

one-time sampling of springs, mine adits, and exploration pits 

in Elk Basin and Redwell Basin; repeated sampling throughout 

one year of Standard Mine Level 1 discharge and Elk Creek 

near its confluence with Coal Creek; and a one-time sampling 

of underground sites in Levels 3 and 5 of the Standard Mine. 

Samples were analyzed for major ions and trace elements, 

stable isotopes of hydrogen (2H/1H) and oxygen (18O/16O), 

strontium isotopes, and tritium and dissolved noble gases 

(including helium isotopes) for tritium/helium-3 age dating.

No clear correlations were observed between natural 

ground-water discharge locations and map-scale faults and 

lithology. Surface observations and the location of groundwater discharge suggest that simple topography, rather than 

large-scale geologic features, primarily controls the occurrence and flow of shallow ground water in Elk Basin. Discrete 

inflows from cross faults or other features were not observed 

in Levels 3 and 5 of the Standard Mine. Instead, water entered 

the mine as relatively persistent dripping from gouge and 

breccia within the Standard fault, which both tunnels follow. 

Therefore, the Standard fault itself is probably the main pathway of ground-water flow from the shallow subsurface to the 

mine workings.

Low pH (as low as 3.2) and elevated concentrations of 

zinc, lead, cadmium, copper, and manganese (commonly 

exceeding water-quality standards for Elk Creek) were measured in samples located within or immediately downgradient 

of areas where sulfides are abundant, including the Standard 

fault, the Elk Lode portal, and the breccia pipe in Redwell 

Basin. Concentrations of these metals were typically low 

and pH values were circumneutral at surrounding locations. 

Metal concentrations in samples collected from underground 

workings in the Standard Mine were also generally higher than 

in samples collected at aboveground sites located outside of 

sulfide-rich areas. Metal concentrations in discharge from the 

Level 1 tunnel were among the highest measured in Elk Basin. 

All of these observations suggest that sulfide-rich mineralized 

rock is the primary control on dissolved metal concentrations 

and pH in ground water in the Standard Mine vicinity. Wasterock piles apparently exert another major control on metal 

concentrations and pH; the lowest pH and highest metal concentrations typically are found in discharge from waste-rock 

piles. Concentrations of several chemical constituents along 

with strontium isotope data indicate that none of the sampled 

waters could have been the primary source of metals in discharge from Level 1. Therefore, this study did not identify the 

primary source location for metals in Level 1 discharge. Possible sources must be located below Levels 3 and 5 or farther 

back into the mountainside than the ends of Levels 3 and 5.

Apparent tritium/helium-3 ground-water ages ranged 

from 0 to 9 yr, and a considerable majority were <1 yr. Tritium 

data and computed initial tritium values (measured tritium 

plus measured tritiogenic helium-3) suggest that much of 

the ground water in the Standard Mine vicinity was weeks to 

months old rather than years old. Tritium, δ2H, and δ18O data 

from water entering into and discharging from the Standard 

Mine displayed spatial and temporal patterns indicating that 

these tracers were influenced by seasonal variations in their 

concentration in precipitation. The tracer data therefore suggest that ground water entering into and discharging from 

the Standard Mine was largely composed of water <1 yr old. 

Pronounced seasonal variations in geochemistry in Level 1 

discharge also are consistent with short residence times for 

much of the water in the Standard Mine. 

Metal concentrations in Elk Creek waters were consistently at least an order of magnitude lower than in Level 1 

discharge, but they still commonly exceeded water quality 

standards for zinc, lead, cadmium, copper, and manganese. 

Estimated metal fluxes along with similar seasonal fluctuations in chemistry (field parameters, chemical constituents, 

and stable isotopes) observed in Level 1 discharge and Elk 

Creek are consistent with Level 1 discharge being the primary 

source of metals in Elk Creek. A prominent feature of the 

time-series data from both Level 1 discharge and Elk Creek 

was a “spring flush” during which pH dropped and metal 

concentrations rose in the early stages of spring runoff.

Hydrogeochemical Investigation of the Standard Mine 

Vicinity, Upper Elk Creek Basin, Colorado

By Andrew H. Manning, Philip L. Verplanck, M. Alisa Mast, and Richard B. Wanty
2 Hydrogeochemical Investigation of the Standard Mine Vicinity, Upper Elk Creek Basin, Colorado

Introduction 

The U.S. Environmental Protection Agency has listed the 

Standard Mine in the Elk Creek drainage near Crested Butte, 

Colo., (fig. 1) as a Superfund site. Drainage from the Standard 

Mine enters Elk Creek, contributing dissolved and suspended 

loads of zinc, cadmium, lead, and other metals. Elk Creek is a 

tributary to Coal Creek, which is the main drinking-water supply for the town of Crested Butte. Dozens of abandoned mines 

and mining prospects cover both the north and south sides of 

Mount Emmons (fig. 1), but portals associated with Standard 

Mine are among the few that continually drain water. The 

Standard Mine has therefore become the focus of attention of 

concerned local citizens and the U.S. Environmental Protection Agency.

This study characterized the ground-water flow system 

in the vicinity of the Standard Mine, in order to assist the 

U.S. Environmental Protection Agency in evaluating remedial 

options for the mine. More specifically, the purpose of this 

study is to attempt to answer the following questions. 

1. Where in the Standard Mine vicinity does metal-rich 

water discharge, and what are the concentrations of metals 

in these waters? 

2. What is the primary source (for instance, geologic 

structure type or rock type) of the elevated metal 

concentrations? 

3. Where is there sufficient permeability to allow substantial 

ground-water flow rates? 

4. What are characteristic ground-water residence times 

and related temporal variations in ground-water flow and 

chemistry? 

5. Within the Standard Mine, where does ground water 

discharge, and what is the chemical composition of the 

different waters contributing to mine outflow?

In order to answer these questions, ground-water and 

surface-water samples were collected from summer 2006 

through spring 2007 from Elk Basin, upper Redwell Basin, 

lower Elk Creek, and within the Standard Mine (fig. 2). 

Samples were analyzed for major ions and trace elements, 

stable isotopes of hydrogen (2H/1H) and oxygen (18O/16O), 

strontium isotopes, and tritium and dissolved noble gases 

(including helium isotopes) for tritium/helium-3 age dating. 

The resulting chemical and isotopic data provide important 

information on the distribution and source of metal-rich 

waters in the Standard Mine vicinity as well as groundwater residence times and seasonal cycles in ground-water 

chemistry. The study is divided into three tasks. Task 1 

consisted of repeated sampling of four locations throughout 

one year to discern seasonal cycles. Task 2 consisted of a onetime survey and sampling of ground-water discharge locations 

(springs, mine portals, and exploration pits) in Elk Basin and 

Redwell Basin. Task 3 consisted of sampling ground water 

inside the Standard Mine.

Site Description

Location and Climate

The Standard Mine lies within the upper Elk Creek 

drainage basin (Elk Basin), a roughly 1 mi2 alpine watershed 

located approximately 4 mi west-northwest of the town of 

Crested Butte in west-central Colorado (fig. 1). Land surface 

elevations in Elk Basin ranged from 10,800 to 12,200 ft above 

sea level, and topographic gradients generally ranged from 0.2 

to 0.6, typical of rugged mountain settings (fig. 2). Vegetation is subalpine to alpine, dominantly mixed spruce and fir 

forest or tundra. The closest meteorological stations are in 

the town Crested Butte at an elevation of 8,860 ft above sea 

level (http://www.wrcc.dri.edu) and at Crested Butte ski area 

approximately 6 mi to the east at an elevation of 10,160 ft 

(http://www.wcc.nrcs.usda.gov/snotel). Data from these stations suggest that Elk Basin has a mean annual air temperature 

of about 1°C and mean annual precipitation of about 31 in./yr; 

approximately 65 percent of that precipitation typically falls as 

snow. Snow cover typically persists from November through 

May. Elk Basin is drained by Elk Creek, which is a perennial 

stream.

Geology

The dominant rock units exposed in the Standard Mine 

vicinity are the Tertiary Wasatch Formation (unit Tw) and 

Tertiary Ohio Creek Formation (unit Toc) (fig. 3; map taken 

from Gaskill and others (1967)). The Wasatch Formation 

consists of fine-grained to very coarse grained sandstone, 

siltstone, and mudstone, with thick lenses of conglomerate 

near its base. The Ohio Creek Formation is similar, consisting 

of sandstone (some conglomeratic), siltstone, shale, and 

carbonaceous shale, with massive pebbly sandstone beds 

near its base. These units are underlain by the Cretaceous 

Mesaverde Formation (unit Kmv), exposed on the north 

side of Scarp Ridge (north of Elk Basin), which consists of 

interbedded sandstone, shale, coal, and carbonaceous shale. 

These fluviolacustrine sedimentary units are intruded by 

mid-Tertiary sills, dikes, laccoliths, and stocks throughout 

the Mt. Emmons area. In the Standard Mine vicinity, quartz 

monzonite porphyry (unit qmp) sills are exposed as are a 

breccia pipe in Redwell Basin and an associated northeasttrending dike. Both the breccia pipe and dike were mapped 

as felsite (unit f) by Gaskill and others (1967) (fig. 3). More 

recent exploration drilling has indicated that the breccia pipe 

is more likely a composite of felsite, igneous breccia, and 

rubble breccia and has suggested that the pipe vented volcanic 

gases and fluids from an unexposed rhyolite–granite porphyry 
Site Description 3

Mt. Emmons

Standard

Mine

Daisy

Mine

Keystone

Mine

Peeler Lakes

Copley

Lake

Crested Butte

Scarp Ridge

Elk Creek

Coal Creek

Oh-Be-Joyful Creek

Redwell Creek

Slate

River

Nicholson

Lake

38°52'30"

38°55’

107 107°05' °

0 0.5 1 MILE

0 0.5 1 KILOMETER

COLORADO

Colorado

Plateau

Southern

Rocky

Mountains

Great Plains

DENVER

Crested Butte

Study area

Figure 1. Location of Standard Mine. Dashed line, ridge crest.
4 Hydrogeochemical Investigation of the Standard Mine Vicinity, Upper Elk Creek Basin, Colorado

Figure 2. Location of three sample areas in Standard Mine vicinity. Base map compiled from U.S. Geological Survey 

1:24,000 topographic maps of the Oh-Be-Joyful, Colo. and Mt. Axtell, Colo. quadrangles (1973). Contour interval, 40 ft.

Elk Basin

Sample

Area

Redwell

Basin

Sample

Area

Lower

Elk Creek

Sample Area

107o05' 107o

04' 107o

03'

38o52'

38o

53'

0 0.5 1 MILE

0 0.5 1 KILOMETER
Site Description 5

Qt

Qt Level 1 portal

Level 2 portal

Level 3 portal

Level 5 portal

Standard Fault

Elk Fault

Redwell

Basin

Elk Lode

portal

0 300 600 900 1,200 1,500 FEET

0 100 200 300 400 500 METERS

107°04’30” 107°04’ 107°03’30”

38°53’30”

38°53’

Propylitically

or phyllically

altered

rocks

Qt

Tw

Ql

Toc

Quaternary talus

deposit

Kmv

Quaternary landslide

deposit

Tertiary Wasatch

Formation

Tertiary Ohio

Creek Formation

Cretaceous 

Mesaverde Formation

qmp Tertiary quartz

monzonite porphyry

f Tertiary felsite

EXPLANATION

Contact—Dashed where approximately

 located

Fault or shear zone—Dashed 

 where inferred. U, upthrown

 side; D, downthrown side.

U

D

16 Strike and dip of beds

Mine adit

Contour interval = 40 ft

 Extent of alteration zone

Figure 3. Geology near Standard Mine. Adapted from Gaskill and others (1967). Base map is U.S. Geological 

Survey 1:24,000 topographic map of Oh-Be-Joyful, Colo. (1973).
6 Hydrogeochemical Investigation of the Standard Mine Vicinity, Upper Elk Creek Basin, Colorado

intrusive complex underlying Redwell Basin at depths greater 

than about 3,000 ft (Sharp, 1978). On the basis of additional 

exploration work, Thomas and Galey (1982) suggest that the 

stock underlying Redwell Basin (Redwell stock) is part of a 

much larger 16–18 million year old (Ma) granite porphyry 

stock that underlies Mt. Emmons and Red Lady Basin to the 

southeast (fig. 2).

The sedimentary units dip gently (10°–20°) to the southwest. Faults in the area are generally steeply dipping, trend 

either northeast or north-northwest, and have trace lengths of 

0.25 to 2 mi. Thomas and Galey (1982) report that the faults 

display relatively small normal-sense offsets of <200 ft. However, more recently, Wanty and others (2003) have reported 

that the northeast trending faults are dominantly strike slip, 

on the basis of fault striation data, and that the two fault sets 

form a strike-slip extensional step-over (or duplex) in the Mt. 

Emmons area. Fault duplexes of this type form in transpressive 

tectonic settings. The age of the faulting is uncertain. Sharp 

(1978) suspects that that they predate intrusion of the granite 

porphyry stock underlying the area (dated at 16–18 Ma) and 

are associated instead with a preintrusion basement fabric 

manifested by the northeast-trending Colorado mineral belt 

(Tweto and Sims, 1963) and the northwest-trending Crested 

Butte lineament (Mutschler, 1968). However, the small displacements displayed by the faults, along with the fact that 

they do not contain granite porphyry, led Thomas and Galey 

(1982) to suspect that they are the result of late adjustments 

in the stock (before or contemporaneous with base metal 

mineralization), neither predating nor controlling the emplacement of the stock. Wanty and others (2003) also suggest that 

the faults are contemporaneous with the stock intrusion, but 

they believe that emplacement of the intrusion was accommodated by localized extension in the duplex, meaning that 

both faulting and intrusion were controlled by the same stress 

field. The faults then controlled the flow of mineralizing fluids 

associated with the intrusion. Wanty and others (2003) emphasize that the presence of hydrothermal veins and mineralization along the principal structures of the duplex indicate that 

these structures accommodated fluid flow in the geologic past 

because they were zones of enhanced permeability. 

The portals associated with the Standard Mine (Levels 1, 

2, 3, and 5 shown on fig. 3) lie on or very close to a northeasttrending fault transecting all of Elk Basin that will henceforth 

be referred to as the Standard fault. The Standard Mine workings generally follow the Standard fault (Colorado Division of 

Reclamation, Mining, and Safety, 2007). Thomas and Galey 

(1982) refer to this structure as the Standard vein. It is one of 

six subparallel faults mapped within Elk Basin and Independence Basin immediately to the northwest that together are 

referred to as the Elk Basin fault zone by Sharp (1978). The 

structure of the Standard fault is described in further detail in a 

draft underground assessment report by the Colorado Division 

of Reclamation, Mining, and Safety (2007). The fault immediately northwest of the Standard fault shall be referred to in this 

report as the Elk fault (fig. 3). 

Hydrothermal alteration and mineralization occur in the 

Standard Mine vicinity as a result of the intrusion of the granite porphyry stock underlying the area. Pervasive propylitic 

alteration (a low-grade form of alteration) occurs in Redwell 

Basin and Evans Basin and barely extends into the northeasternmost part of Elk Basin (fig. 3). Propylitically altered rocks 

typically contain pyrite, epidote, calcite-siderite, and chlorite. 

Although they contain pyrite, these rocks typically do not 

produce low-pH and metal-rich waters owing to the buffering capacity of the other minerals present in the assemblage. 

Thomas and Galey (1982) report that the propylitically altered 

rocks exposed at the surface in the area contain <1 percent 

pyrite. Higher grade phyllic hydrothermal alteration occurs in 

the immediate vicinity of the breccia pipe in Redwell Basin, 

characterized by quartz, sericite, pyrite-pyrrhotite, fluorite, 

and calcite-siderite-rhodochrosite. Phyllically altered rocks 

commonly do produce low-pH and metal-rich waters owing to 

their high pyrite content and low buffering capacity.

Outside of the zone of pervasive alteration shown on 

figure 3, hydrothermally altered and mineralized rocks are 

generally sparse and restricted to faults, veins, and rocks 

immediately adjacent to these features (Thomas and Galey, 

1982). This distribution suggests that hydrothermal fluid flow 

associated with the intrusion was similarly restricted to faults 

outside of the immediate vicinity of the granite porphyry intrusion (Wanty and others, 2003). Sulfide minerals within the 

Standard fault and other faults and veins in the Mt. Emmons 

area include sphalerite, pyrite, pyrrhotite, argentiferous galena, 

and chalcopyrite. Fault and vein ores have produced base and 

precious metals. In addition to the altered and mineralized 

rock exposed at the surface, phyllic and higher grade potassic 

alteration have been identified at depth under both Redwell 

Basin and Red Lady Basin, closer to the granite porphyry 

stock. Three molybdenite deposits were discovered associated with this alteration, two beneath Redwell Basin (Sharp, 

1978) and another higher grade deposit below Red Lady Basin 

(Thomas and Galey, 1982).

Mining Activities

The Standard Mine and other mines in the Mt. Emmons 

area are in the Ruby mining district. Ores within faults and 

veins in the Mt. Emmons area were mined for base and 

precious metals from the 1880s to the early 1970s. The principal mines in the Mt. Emmons area include the Keystone Mine 

on the southern flank of Mt. Emmons between Evans and 

Red Lady Basins, the Daisy Mine in Redwell Basin, and the 

Standard Mine (fig. 1). A review of the history and development of the Standard Mine is provided in a draft underground 

assessment by the Colorado Division of Reclamation, Mining, 

and Safety (2007). Extensive exploration drilling in the 1970s 

identified and characterized the three molybdenite deposits 

beneath Redwell and Red Lady Basins. These deposits have 

not been mined.
Methods 7

The workings of the Standard Mine are described in 

detail in a draft underground assessment (Colorado Division 

of Reclamation, Mining, and Safety, 2007). Briefly, the mine 

consists of four adits and several stopes and shafts that generally follow the Standard fault (fig. 4). The adits are designated 

Levels 1, 2, 3, and 5, in sequence from lowermost to uppermost. Levels 1, 2, and 3 are connected by stopes or raises. The 

level 5 tunnel is not connected to the other levels. The Level 1 

and Level 5 portals are the only portals that consistently drain 

water. In August 2006, water was observed inside Level 3 that 

was draining to lower levels through raises. Level 1 discharges 

considerably more water than the other levels and is thus the 

largest potential source of metals in Elk Creek associated with 

the Standard Mine. 

Previous Hydrogeologic Studies

We are aware of no prior hydrogeologic or geochemical 

investigations specifically of Elk Basin or the Standard Mine. 

However, surface- and ground-water geochemistry in the Mt. 

Emmons area has been studied by the U.S. Geological Survey 

in recent years, focused mainly in Redwell Basin. Verplanck 

and others (2004) present the results of chemical analysis of 

43 water samples collected from springs, streams, and mine 

drainages within the Mt. Emmons area. These samples were 

analyzed for major and trace elements and strontium (Sr) 

isotopes. The major and trace element data indicate that the 

sampled waters can be divided into three main types. Type I 

waters, referred to as “Group 1-2 samples” (Verplanck and 

others, 2004), have circumneutral pH and are relatively dilute 

(iron concentrations on the order of 0.01 milligrams per liter 

(mg/L) and zinc concentrations on the order of 0.1 mg/L). 

These samples were collected primarily from springs and 

stream sites within unmineralized (calcium-rich and sulfidepoor) sedimentary rocks. Type II waters (“Group 4-5 samples,” Verplanck and others, 2004) are acidic (pH typically 

3–4) with elevated concentrations of several major elements 

(iron concentrations on the order of 1–10 mg/L) and most 

trace metals (zinc concentrations on the order of 1 mg/L). 

Many of these samples were collected from mine drainages 

and other sites within or immediately downgradient of basemetal mineralized rock, which generally is close to the breccia 

pipe in Redwell Basin or within faults and veins throughout 

the area. Type III waters (“Group 3 samples,” Verplanck and 

others, 2004) are intermediate between Types I and II, owing 

either to mixing between Type I and Type II waters or to lesser 

degrees of water-rock interaction within mineralized rock 

(possibly shorter flow pathways). All samples collected from 

sites within base-metal mineralized rock have similar 87Sr/86Sr 

isotope ratios (0.7134–0.7143), whereas other samples have 

different and more widely varying 87Sr/86Sr isotope ratios 

(0.7114–0.7166). The study by Verplanck and others (2004) 

therefore suggests that acidic and metal-rich waters (Type II) 

near the Standard Mine may be closely associated with faults 

and veins, which apparently host mineralized rock, and that Sr 

isotopes may be a useful tool for identifying waters that have 

interacted with mineralized rock when flow paths are uncertain or other chemical parameters do not clearly indicate this 

interaction.

As previously noted, map-scale faults apparently controlled the flow of hydrothermal fluids in the Mt. Emmons 

area in the geologic past. An important question is whether or 

not these structures are zones of enhanced permeability and 

ground-water flow in the current hydrogeologic regime. Wanty 

and others (2003) performed a tracer dilution study in Redwell 

Creek to address this question. The tracer test was conducted 

by continuously injecting lithium chloride (LiCl) into the 

headwaters of Redwell Creek for 24 hours (h) and collecting 

68 synoptic samples from Redwell Creek and all its tributaries 

when the tracer had reached steady-state concentrations along 

the study reach. The concentration of the tracer decreased 

downstream of each tributary, as expected, but the tracer also 

decreased along the reach where Redwell Creek flows along 

a set of well-developed, laterally continuous north-south 

fractures. The dilution of the tracer within this fracture zone 

documented an input of water to Redwell Creek, although no 

surface tributaries existed in that reach. Groundwater discharge from the north-south fracture set is the most probable 

source of the additional water. Therefore the primary fractures 

in the duplex do appear to serve as preferential ground-water 

flow pathways in Redwell Basin. There is little reason to 

believe that the same is not true throughout the Standard Mine 

vicinity and thus that the Standard fault, Elk fault, and other 

map-scale faults in Elk Basin (fig. 3) may also serve as 

preferential ground-water-flow pathways.

Acknowledgments

This study was performed in cooperation with the U.S. 

Environmental Protection Agency. We greatly appreciate the 

efforts of Steve Renner, Jim Herron, and Jeff Graves of the 

Colorado Division of Reclamation, Mining, and Safety for 

escorting us into the mine. We thank Robert Runkel and David 

Borrok for their helpful reviews of this report.

Methods

Study Approach

This study was divided into three tasks. Task 1 consisted 

of repeated sampling of the Standard Mine Level 1 portal 

and of Lower Elk Creek near the confluence with Coal Creek 

during the course of one year. Of 8 sampling events, 4 were 

during spring runoff and 4 were spread throughout the rest of 

the year. In addition, two springs in Elk Basin were sampled 

twice, once in late summer (low flow period) and once in the 
Level 1 Level 2 Level 3 Level 4 Level 5 0 200 300 FE

0 50 100 M

100

Elk Creek

N 52°47’44”E N 65°42’44”E

Figure 4. Cross section of Standard Mine. Adapted from Colorado Division of Reclamation, Mining, and Safety (2007).
Methods 9

spring (high flow period). The objectives of task 1 were to 

observe seasonal variations in water chemistry in Standard 

Mine discharge and to compare these variations with those in 

Elk Creek and in ground water in the rest of Elk Basin. Task 2 

consisted of a one-time survey and sampling of ground-water 

discharge locations (springs, mine workings, and wells) in 

the Standard Mine vicinity. The objectives of task 2 were to 

(1) determine the location of metal-rich ground water in the 

Standard Mine vicinity; (2) place metal concentrations in 

Standard Mine discharge in context with other ground water 

in Elk Basin; (3) determine the source of metal-rich water in 

Elk Basin; (4) assess possible geological controls on groundwater flow in the area; and (5) characterize ground-water 

residence times. Task 3 consisted of entering the Standard 

Mine, observing where and how ground water enters the mine, 

and sampling this water. The objective of task 3 was to better 

understand the source of ground water and dissolved metals 

discharging from the Level 1 portal.

Description of Methods

Major Ion and Trace Element Chemistry

Because alpine ground-water recharge is dilute precipitation, the primary source of solutes in ground water in the 

study area should be water-rock interactions. Major and trace 

element data therefore can be used to determine the mineral 

assemblages or rock types through which water has flowed. 

This approach has been used successfully in the Mt. Emmons 

area and other alpine settings to categorize waters on the basis 

of rock types with which they have interacted, thus providing 

important information on flow pathways and sources of high 

metal concentrations (Verplanck and others, 2004; Wanty and 

others, 2004). Major and trace element concentrations were 

measured in this study to determine metal concentrations 

in Standard Mine drainage, how these concentrations vary 

seasonally, and how they compare with ground water in the 

mine vicinity, as well as to discern possible ground-water flow 

pathways. 

Strontium Isotopes

A comprehensive review of Sr isotope techniques is 

provided by Faure (1986). Strontium has four stable, naturally 

occurring isotopes (84Sr, 86Sr, 87Sr, and 88Sr). The isotopic 

abundance of 87Sr is variable because it is produced by the 

radioactive decay of naturally occurring 87Rb with a half 

life of ~4.8×1010 years (yr). Strontium isotopes have been 

shown to be useful hydrologic tracers for three reasons: the 

strontium isotope composition of ground water is primarily 

controlled by the rock through which the ground water flows 

(in other words, by water-rock interactions); unlike lighter 

isotopes, strontium isotopes do not produce mass-dependent 

fractions; and high-precision measurements can be routinely 

made after only minor chemical separations. 87Sr/86Sr ratios 

differ in different rock types because rocks formed in different 

geologic environments can have different initial 87Sr/86Sr, 

and rocks that are older or have a greater Rb/Sr ratio will 

have more radiogenic 87Sr. As noted above, previous work 

in the Mt. Emmons area suggests that the strontium isotope 

signature (87Sr /86Sr) of ground water can differentiate waters 

that have interacted with mineralized or unmineralized rock 

(Verplanck and others, 2004). Strontium isotope compositions 

were therefore coupled with major and trace element data to 

help constrain the origin and evolution of discharging ground 

waters in the vicinity of the Standard Mine.

Deuterium and Oxygen-18 

A comprehensive review of the use of 2H/1H and 18O/16O

isotope ratios in ground-water studies is provided by Coplen 

and others (2000). Deuterium (2H) and oxygen-18 (18O) are 

stable isotopes of hydrogen and oxygen, respectively, that 

occur naturally in water. Because they are heavier than the 

dominant isotopes of hydrogen and oxygen (1H and 16O), they 

behave differently than 1H and 16O during evaporation and 

condensation (precipitation). As a result, 2H/1H and 18O/16O

isotope ratios vary spatially and temporally in meteoric waters, 

reflecting varying pathways through the hydrologic cycle. 

Stable isotopic ratios are reported relative to a standard as δ 

values in units of per mil, defined as:

 

where Rx and Rstd are 2H/1H or 18O/16O of the sample and standard, respectively. As is customary, δ2

H and δ18O are reported 

relative to Vienna Standard Mean Ocean Water in this study. 

The δ2H and δ18O values of meteoric waters are generally 

negative because 2H/1H and 18O/16O ratios in precipitation are 

lower than in sea water.

Precipitation δ2H and δ18O values typically follow a 

seasonal cycle. Cold winter precipitation has lower values 

(more negative, or “lighter”) and warm summer precipitation 

has higher values (less negative, or “heavier”). As a result, δ2H 

and δ18O values in ground water that has followed short flow 

pathways (residence times of less than a year) vary with time, 

displaying the influence of these seasonal variations in precipitation. In contrast, δ2

H and δ18O values in ground water that 

has followed longer flow pathways (residence times of years) 

are relatively constant through time, equal to the seasonal 

average of recharged precipitation. Seasonal variations in δ2H 

and δ18O (or lack thereof) are therefore potentially useful in 

determining the relative contribution of short-and-fast or longand-slow flow paths to a ground-water discharge location. 

Stable isotope data were obtained for samples collected as part 

of tasks 1 and 3 to discern the relative abundance of seasonal 

(younger) and base-flow (older) components in water entering 

into and discharging from the Standard Mine.

X = Rx

Rstd

–1 × 1,000
10 Hydrogeochemical Investigation of the Standard Mine Vicinity, Upper Elk Creek Basin, Colorado

Ground-Water Age Dating

The most direct way to determine flow pathway length 

and residence time is to use ground-water dating techniques. 

The tritium/helium-3 (3H/3He) method was used because it 

was expected that most waters would fall within the age range 

of the method, which is 0–50 yr. A comprehensive review of 

the 3H/3He method is provided by Solomon and Cook (2000). 

The method is generally considered to be the most robust 

of the techniques for dating young ground water because it 

is least affected by complications arising from degradation, 

contamination from anthropogenic sources, and mixing of 

ground waters of different ages (Manning and others, 2005). 

Tritium is a radioactive isotope of hydrogen that naturally 

occurs in water and decays to 3He with a half-life of 12.32 

yr. Natural concentrations of 3H in precipitation are generally 

4–8 tritium units (TU; 1 TU = 1 atom of 3H per 1,018 atoms 

of hydrogen). Atmospheric thermonuclear testing in the 1950s 

and early 1960s introduced large amounts of 3H to the atmosphere, resulting in precipitation 3

H concentrations >1,000 TU 

and providing ample 3H to allow ground water recharged after 

the early 1950s (postbomb water) to be dated using the 3H/3He 

method. Because both 3H and 3He are chemically inert in the 

ground-water system, their concentrations change only as a 

function of time in the subsurface. The age of a ground-water 

sample is determined by measuring both 3H and tritiumderived (tritiogenic) 3

He concentrations and then using their 

ratio along with the radioactive decay equation to compute 

the time elapsed since the sampled water entered the saturated 

zone. Tritium/3He ground-water ages have proven very useful 

in developing conceptual models of alpine fractured-rock 

ground-water flow systems, which are typically highly complex (for example, Manning and Caine, 2007). Tritium/3

He 

ground-water ages were obtained from the Standard Mine 

vicinity to help identify zones of high versus low flow velocities and short versus long flow pathways.

The tritiogenic component of 3He in a sample (3Hetrit) 

is determined by calculating all other 3He components, then 

subtracting them from the total measured 3He. These other 3He 

components include solubility, excess air, and terrigenic components. The total 3

He concentration is determined by multiplying the measured total He concentration by the measured 

3

He/4He ratio (R). The measured 3He/4He ratio is expressed 

in the form R/Ra, where Ra is the 3He/4He ratio in air. The 

solubility 3He component is acquired at the time of recharge 

from gas exchange between the sampled water and air in the 

unsaturated zone. It is governed by Henry’s Law and is a 

function of the recharge temperature (Tr) and recharge pressure, which are the temperature and air pressure at the water 

table at the point of recharge. The recharge pressure is a direct 

function of the recharge elevation (Hr), which is typically well 

constrained and is thus assumed. In many cases, Tr is more 

uncertain and is therefore computed from the concentration of 

other noble gases measured along with He—neon (Ne), argon 

(Ar), krypton (Kr), and xenon (Xe). Excess air is a component 

of dissolved gas in excess of solubility concentrations that is 

ubiquitous in ground water and has an air-like composition. 

Kipfer and others (2002) provide a complete review of current models of excess air formation. Excess air is believed to 

originate from the entrapment and subsequent dissolution of 

air bubbles near the water table when the water table rises. The 

most current and widely used model for excess air entrainment, and that used in this study, is the closed equilibrium 

model. In this model, excess air concentrations are governed 

by two parameters, Ae and F. Ae is the amount of air trapped 

when the water table rises, and F describes the degree to which 

gases become fractionated during partial bubble dissolution. 

Ae and F also must be computed from the concentration of the 

other measured noble gases (Ne, Ar, Kr, and Xe). In this study, 

the total excess air concentration is also reported for reference. 

This concentration is defined as the sum of the modeled excess 

components of nitrogen (N2), oxygen (O2), and Ar. After the 

recharge parameters Hr, Tr, Ae, and F are either assumed or 

computed, the solubility and excess air components of 3He can 

be calculated.

After recharge, ground water can acquire terrigenic He 

(Heterr) as a result of either radioactive decay of U and Th in 

aquifer materials or from upward leakage of mantle gases and 

fluids. Heterr is determined by subtracting the solubility and 

excess air He components from the total measured He. The 

terrigenic component of 3He is then computed by multiplying 

Heterr by an assumed 3He/4He ratio for Heterr. If Heterr concentrations in a sample are too high (greater than about 5×10–8

cubic centimeters of gas at standard temperature and pressure 

per gram of water (cm3STP/g)), then the magnitude of 3Hetrit

becomes highly uncertain owing to uncertainty in the assumed 

3

He/4He ratio for Heterr, and a reliable 3H/3He age cannot be 

determined. Typically only samples with ages considerably 

greater than 50 yr or samples collected in areas of active volcanism have elevated Heterr concentrations. 

The age range of the carbon-14 age dating technique is 

1,000–50,000 yr. A comprehensive review of the carbon-14 

method is provided by Kalin (2000). The method is based on 

the radioactive decay of the carbon-14 (14C) isotope (half-life 

of 5,730 yr) in dissolved inorganic carbon in ground water. 

Carbon-14 is produced in the upper atmosphere and mixes into 

the lower atmosphere in the form of 14CO2. Carbon-14 enters 

the ground-water system during recharge as soil CO2 produced 

by plant root respiration and microbial degradation of organic 

material that dissolves in infiltrating ground water. After 

entering the saturated zone, interaction with soil CO2 ceases 

and 14C in the dissolved inorganic carbon decays with time. 

By convention, the modern pre-1950 (before open-air nuclear 

bomb testing) activity of atmospheric 14C is 100 percent modern carbon. Two samples collected in this study were analyzed 

for carbon isotopes to determine whether some of the ground 

water near the Standard Mine might follow very long or slow 

flow pathways (or both) and might thus to a degree be disconnected from the active ground-water flow system.
Methods 11

Sample Collection and Analysis

This section provides a general description of sample 

collection and analysis methods. Samples were collected and 

analyzed as described in appendix 1, Sampling and Analysis 

Plan, which provides additional details regarding collection 

and analytical methods.

Major Ion and Trace Element Chemistry

Onsite measurements of pH, specific conductance, 

temperature, dissolved oxygen, and redox potential (Eh) 

were obtained. At each site the pH electrode calibration was 

checked and, when necessary, recalibrated using two buffers 

that bracketed the measured pH. Samples were filtered onsite 

through a syringe filter having a pore size of 0.45 μm. Several 

sample aliquots were collected for determination of concentrations of inorganic constituents and redox species (Fe+2/Fe+3). 

Container preparation and stabilization of filtered samples 

included an unfiltered, nitric-acid-acidified aliquot for totalrecoverable major cation and trace element determinations; a 

filtered, nitric-acid-acidified aliquot for dissolved major cation 

and trace element determinations; a filtered, nonacidified 

aliquot for anion and alkalinity determinations; and a filtered, 

hydrochloric-acid-acidified aliquot for iron redox species 

determinations. Bottles for both filtered and unfiltered nitricacid-acidified aliquots were soaked in nitric acid, rinsed in 

distilled water, and then rinsed with sample water. Bottles for 

filtered, nonacidified aliquots were soaked in distilled water 

and rinsed with sample water. Opaque bottles for iron redox 

aliquots were soaked in hydrochloric acid, rinsed in distilled 

water, and then rinsed with sample water. Appropriate aliquots 

were acidified with ultrapure acid and then stored on ice until 

refrigerated.

All analyses for major ion and trace element chemistry 

were performed at U.S. Geological Survey laboratories in 

Denver or Boulder, Colo. All reagents were of a purity at least 

equal to the reagent-grade standards of the American Chemical Society. Double-distilled deionized water and redistilled 

acids using a subboiling purification technique (Kuehner 

and others, 1972) were used in all preparations. The methods and detection limit for each analysis are summarized in 

table 1. U.S. Geological Survey standard reference water 

samples and blanks were included with each sample suite for 

inductively coupled plasma–atomic emission spectroscopy 

(ICP–AES) and inductively coupled plasma–mass spectrometry (ICP–MS). Major cations (Ca, Mg, K, and Na) and 

silica and selected trace elements (aluminum, boron, barium, 

copper, iron, manganese, lead, strontium, and zinc) for totalrecoverable and dissolved samples were determined using a 

Perkin Elmer Optima 3000TM ICP–AES (Briggs, 2002). Trace 

elements for total-recoverable and dissolved samples were 

analyzed with the ICP–MS using a method developed by the 

U.S. Geological Survey (Meier and others, 1994; Lamothe and 

others, 2002). This method is used to directly determine the 

elements in the water samples without need for any preconcentration or dilution. Elemental detection limits for most trace 

metals are in the subparts per billion range (table 1), and the 

working linear range is six or more orders of magnitude.

Concentrations of major anions (Cl–, F–, NO3

–

 and SO4

–

) 

were determined by ion chromatography (Theodorakos and 

others, 2002); a Dionex DX500TM ion chromatograph with 

5-microliter (μL) and 10-μL sample loops was used. Standards 

were prepared from compounds of the highest commercially 

available purity. U.S. Geological Survey standard reference 

water samples were used as independent quality-control 

standards. Alkalinity (as HCO3

–

) was determined using an 

Orion 960TM autotitrator and standardized H2SO4 (Barringer 

and Johnsson, 1989). Samples were diluted as necessary to 

bring the analyte concentration within the optimal range of the 

method. Iron(II) redox species and total iron in filtered, HClacidified samples were determined by using a modification 

of the FerroZineTM colorimetric method (Stookey, 1970; To 

and others, 1999) with a Hewlett Packard 8453TM diode array 

ultraviolet-visible spectrophotometer.

Strontium Isotopes

Measured aliquots of sample water were placed in 

Savillex® containers, evaporated, and the strontium was then 

separated for each sample using SrSpec® resin. During the 

study period total procedural blanks for strontium were ≤30 pg 

and were negligible compared with the amount of strontium 

processed for a given sample. Isotopic analyses of strontium 

separates were performed at the U.S. Geological Survey in 

Denver, Colo., by using a Nu Instruments® double focusing, 

high-resolution multicollector inductively coupled plasma 

mass spectrometer (MC–ICP–MS) and at the University of 

Colorado, Boulder, by using a Finnigan-MAT 261, 6-collector 

thermal ionization mass spectrometer. By use of the MC–ICP–

MS, strontium samples were dissolved in 2 percent HNO3 and 

introduced into the argon plasma through a desolvating nebulizer system (Nu Instruments DSN100). Seven measurements 

of the standard SRM-987 during the study period yielded 

mean 87Sr/86Sr = 0.71024±2. By using the thermal ionization 

mass spectrometer, 87Sr/86Sr ratios were analyzed using fourcollector static mode measurements, and SRM-987 during the 

study period yielded mean 87Sr/86Sr = 0.71031±1. Because of 

the consistent difference in the measurements of SRM-987 

between the two instruments, data from the MC–ICP–MS 

were normalized to SRM-987 of 0.71031. For two samples 

(EC–MSTDL32–01 and EC–MSTDL35–01), the same aliquot 

of strontium was analyzed on both instruments and, after the 

MC–ICP–MS data were normalized, the 87Sr/86Sr ratios were 

within analytical error.
12 Hydrogeochemical Investigation of the Standard Mine Vicinity, Upper Elk Creek Basin, Colorado

Table 1. Methods of analysis and detection limits.

[mg/L, micrograms per liter; mg/L, milligrams per liter; IC, ion chromatography; ICP–AES, inductively 

coupled plasma-atomic emission spectroscopy; ICP–MS, inductively coupled plasma-mass spectrometry]

Element Detection

limit Method Element Detectionlimit Method

Ag 1 mg/L ICP–MS Mn 10 mg/L ICP–AES

Al 20 mg/L ICP–AES Mn 0.2 mg/L ICP–MS

Al 2 mg/L ICP–MS Mo 2 mg/L ICP–MS

As 1 mg/L ICP–MS Na 0.1 mg/L ICP–AES

B 5 mg/L ICP–AES Nb 0.2 mg/L ICP–MS

Ba 1 mg/L ICP–AES Nd 0.01 mg/L ICP–MS

Ba 0.2 mg/L ICP–MS Ni 0.4 mg/L ICP–MS

Be 0.05 mg/L ICP–MS NO3

– 0.05 mg/L IC

Bi 0.2 mg/L ICP–MS P 10 mg/L ICP–MS

Ca 0.1 mg/L ICP–AES Pb 50 mg/L ICP–AES

Cd 0.02 mg/L ICP–MS Pb 0.05 mg/L ICP–MS

Ce 0.01 mg/L ICP–MS Pr 0.01 mg/L ICP–MS

Cl– 0.03, 0.05 mg/L1 IC Rb 0.01 mg/L ICP–MS

Co 0.02 mg/L ICP–MS Sb 0.3 mg/L ICP–MS

Cr 1 mg/L ICP–MS Sc 0.6 mg/L ICP–MS

Cs 0.02 mg/L ICP–MS Se 1 mg/L ICP–MS

Cu 10 mg/L ICP-AES SiO2 0.1 mg/L ICP–AES

Cu 0.5 mg/L ICP–MS SiO4

– 0.1, 0.05 mg/L1 IC

Dy 0.005 mg/L ICP–MS Sm 0.01 mg/L ICP–MS

Er 0.005 mg/L ICP–MS Sr 1 mg/L ICP–AES

Eu 0.005 mg/L ICP–MS Sr 0.5 mg/L ICP–MS

F– 0.03, 0.05 mg/L1 IC Ta 0.02 mg/L ICP–MS

Fe 20 mg/L ICP–AES Tb 0.005 mg/L ICP–MS

Fe 2 mg/L FerroZine Th 0.2 mg/L ICP–MS

Fe (II) 2 mg/L FerroZine Ti 0.5 mg/L ICP–MS

Ga 0.05 mg/L ICP–MS Tl 0.15 mg/L ICP–MS

Gd 0.005 mg/L ICP–MS Tm 0.005 mg/L ICP–MS

Ge 0.05 mg/L ICP–MS U 0.1 mg/L ICP–MS

Ho 0.005 mg/L ICP–MS V 0.5 mg/L ICP–MS

K 0.1 mg/L ICP–AES W 0.5 mg/L ICP–MS

K 30 mg/L ICP–MS Y 0.01 mg/L ICP–MS

La 0.01 mg/L ICP–MS Yb 0.005 mg/L ICP–MS

Li 0.2 mg/L ICP–MS Zn 20 mg/L ICP–AES

Lu 0.1 mg/L ICP–MS Zn 0.5 mg/L ICP–MS

Mg 0.1 mg/L ICP–AES Zr 0.2 mg/L ICP–MS

1

Detection limit changed January 2007.
Methods 13

Deuterium and Oxygen-18 

Samples for 2H and 18O analysis were collected in borosilicate glass vials (unfiltered, unpreserved). Analyses were 

performed at the U.S. Geological Survey Stable Isotope Laboratory in Denver, Colo. Samples were prepared for 2

H analysis 

offline by zinc reduction as described by Kendall and Coplen 

(1985). Sample H2 gas was admitted to a mass spectrometer 

and δ2H measured by dual-inlet viscous flow. Analytical 

uncertainty (1σ) is ±2.0 per mil. Sample preparation for 18O 

analysis was performed by online equilibration with CO2 as 

described by Epstein and Mayeda (1953), with slight modification to accommodate automated sample preparation and 

analysis. Following equilibration with the sample, headspace 

CO2 was extracted, purified, and admitted to a mass spectrometer and δ18O measured by dual inlet viscous flow. Analytical uncertainty (1σ) is ±0.15 per mil. Final reported δ2

H and 

δ18O values were scaled against Vienna Standard Mean Ocean 

Water.

Tritium

Tritium samples were collected in 500 mL high-density 

polyethylene bottles (unfiltered, unpreserved). Tritium analyses were performed by the U.S. Geological Survey Noble Gas 

Laboratory in Denver, Colo., using the 3He ingrowth method 

described by Bayer and others (1989). A portion of the sample 

is placed in an airtight tritium extraction flask, degassed, 

sealed, and then stored for approximately 100 days to allow 

the accumulation of tritiogenically produced 3He. The accumulated 3

He is then measured using a magnetic-sector mass 

spectrometer. The original 3H concentration at the time of 

sampling is calculated from the measured 3He concentration 

using a known decay constant (0.05621 yr–1). The detection 

limit is approximately 0.05 TU. Analytical uncertainty (1σ) 

ranges from 0.05 TU at low concentrations (<1 TU) to 0.2 TU 

at higher concentrations (>5 TU). 

Dissolved Gases

Dissolved gas samples were collected following the 

general guidelines described in Stute and Schlosser (2000). 

Samples were collected in approximately 18-in.-long sections 

of 3/8-in.-diameter copper tube. Ground water was pumped 

directly from the discharge point through a copper tube using a 

peristaltic pump, preventing any contact between the pumped 

water and the atmosphere upstream of the copper tube. Back 

pressure was maintained on the pumped water using a flowregulating valve at the downstream end of a length of clear 

plastic tube attached to the downstream end of the copper 

tube. The clear plastic tube was monitored to ensure that the 

flowing water was free of bubbles. After sufficient purging, 

the sample was sealed in the copper tube using stainless steal 

pinch-off clamps.

Dissolved gas analyses were performed at the U.S. 

Geological Survey Noble Gas Laboratory in Denver, Colo. 

Dissolved gases were extracted from samples by using an ultra 

high vacuum extraction line. Major component gases (nitrogen, oxygen, carbon dioxide, and methane) were measured on 

a quadrupole mass spectrometer in dynamic operation mode. 

Major component gases were then removed by chemical reaction with a heated titanium and zirconium sponge, and remaining noble gases were separated cryogenically. Noble gas 

concentrations and isotope compositions (He, Ne, Ar, Kr, Xe, 

and the 3He/4He ratio reported as R/Ra) were measured using 

separate aliquots on a magnetic-sector mass spectrometer run 

in static operation mode. All gas concentrations are reported 

in units of cubic centimeters at standard temperature (0°C) 

and pressure (1 atmosphere) per gram of water (cm3STP/g). 

Measurement uncertainties (1σ) are 2 percent for nitrogen, 2 

percent for He, 1 percent for 3He/4He ratio, 3 percent for Ne, 2 

percent for Ar, 3 percent for Kr, and 3 percent for Xe. 

Carbon Isotopes

Carbon isotope samples were collected in 1 L safetycoated glass bottles with septum caps. A peristaltic pump was 

used to pump ground water directly from the discharge point 

through an inline 0.45-μm disposable filter and into the sample 

bottle. The discharge end of the tube from the pump and filter 

was placed at the bottom of the sample bottle allowing the 

bottle to fill from the bottom, minimizing contact between the 

sampled water and the atmosphere. The bottle was allowed 

to overflow and continue overflowing for at least 1 minute, 

purging the bottle. After purging, the tube was slowly removed 

from the bottle and the bottle was immediately capped. The 

septum cap was secured with electrical tape.

δ13C and 14C activity of dissolved inorganic carbon 

were measured at the University of Waterloo Environmental 

Isotope Laboratory (Ontario, Canada) by isotope ratio–mass 

spectrometry (IR–MS) and at the University of Arizona using 

accelerator mass spectrometry (AMS), respectively. Dissolved 

inorganic carbon was extracted from solution in the form of 

CO2 gas by acidification under vacuum by the University of 

Waterloo Environmental Isotope Laboratory, and the CO2

gas was sealed in glass breakseals. δ13C was determined for 

the CO2 gas on the Vienna Pee Dee Belemnite scale. One 

of the breakseals was then sent to the University of Arizona 

for graphite target preparation and 14C measurement. Details 

regarding methods used by the University of Arizona AMS 

facility for 14C determinations can be found in Donahue and 

others (1990). Analytical errors (1σ) typically are 0.15 per mil 

for δ13C and 0.5 percent modern carbon for 14C. 

All 14C activity measurements are reported as the 14C 

activity ratio, 14a, expressed in percent modern carbon at the 

time of sampling, not normalized for 13C fractionation, and 

defined as:

 

 

 

where 14Asample is the absolute (specific) 14C activity of the 

sample (in disintegrations per minute per gram of carbon), and 

pmC = 14a × 100 = 

14A

14A

sample

reference

×100
14 Hydrogeochemical Investigation of the Standard Mine Vicinity, Upper Elk Creek Basin, Colorado

14Areference is the standard activity defined as 95 percent of the 

activity of National Bureau of Standards oxalic acid 

(Ox 1) in the year A.D. 1950. Further explanation of these 

reporting units in comparison to other common reporting units 

for 14C activity measurements is provided by Plummer and 

others (2004).

Quality Assurance and Quality Control

A complete description of quality assurance and quality 

control methods is presented in appendix 1. For stable water 

isotope ratios (δ2H and δ18O), 3H, dissolved gases, and carbon 

isotopes, quality control included collecting sample replicates 

at a rate of 1 in 10 and comparing differences in measurements 

between replicate pairs with the analytical error reported for 

the method. Replicate samples are two field-collected samples 

from the same location that are considered to be essentially 

identical in composition. Each replicate sample was collected 

immediately following the original (replicated) sample and 

was processed through all the same steps. For filtered samples, 

a new filter was used for the replicate. Replicate samples were 

analyzed using the same instruments as the original samples.

For major ions and trace elements, quality control 

methods were more extensive and included replicate samples, 

field equipment blanks, analyses by alternative methods, and 

calculation of charge imbalance. A field equipment blank is a 

sample prepared using deionized water passed through all the 

sampling and processing equipment. This type of sample is 

used to check for potential contamination of samples during 

collection, processing, handling, and analysis. Concentrations 

of cations were determined by ICP–AES and ICP–MS, allowing comparison of cation concentrations measured using two 

different methods. Barium, manganese, and strontium were 

chosen for this comparison because the range in concentrations of these elements was within the working range of both 

analytical techniques. Data for all samples with complete analyses were checked using the computer program WATEQ4F 

(Ball and Nordstrom, 1991) for charge imbalance in percent, 

by using the following calculation:

where sum cations is the sum of the cations in milliequivalents 

per liter, and sum anions is the sum of the anions in milliequivalents per liter. The percent charge imbalance reflects how 

well the major anions and cations balance and is an independent measure of the accuracy of the analytical techniques.

Results

Sixty-six samples were collected from 33 sample sites 

located in 3 sample areas near the Standard Mine (fig. 2). All 

sample information, including analyses performed on each 

sample, is shown in appendix 2. Analytical results for replicate 

samples are included in the analytical results tables referred to 

below (denoted with a sample name ending with R), and they 

are listed immediately following their corresponding original 

sample. Sample site locations are shown in figures 5, 6, and 7. 

Aboveground sample data shown in map-view figures referred 

to below were collected in August 2006, except for data from 

the Elk Creek and Level 2 waste rock sites, which were collected in July 2006.

Survey of Ground-Water Discharge Locations 

and Sample Site Selection

Before samples were collected, ground-water discharge 

points in Elk Basin were surveyed in August 2006 as part of 

task 2 to discern any patterns in the distribution of discharge 

points and to select sample sites. The survey was not intended 

to be comprehensive, but it was undertaken in sufficient 

detail to include most discharge locations in Elk Basin and 

thus permit a representative sample set. It is unlikely that any 

high-flow discharge points (major contributors to Elk Creek) 

were missed in the survey, because they generally produce 

tributaries and vegetation patterns that are easily seen. Of the 

observed waters, those that were not sampled were dilute 

(specific conductance <100 microsiemens per centimeter 

(μS/cm)), had a circumneutral pH (5.5–8.0), and had average 

to low discharge rates (<2 gallons per minute (gpm)). 

Ground-water in Elk Basin discharges from springs and 

mine adits and is observed in exploration pits. Estimated 

spring discharge rates ranged from <1 gpm (seeps) to about 

10 gpm; typical discharge rates are <2 gpm (appendix 2). 

Seventeen spring discharge locations were observed, including three broad areas of either diffuse discharge or multiple 

discharge points. From these 17 locations, 13 discrete springs 

were selected as sample sites (springs 1–12 and Level 2 waste 

rock, fig. 5). Spring sampling sites were selected on the basis 

of three guidelines: all waters that were somewhat acidic (pH 

<6) or chemically evolved (specific conductance over about 

100 μS/cm) were sampled; good areal distribution was sought; 

and if several discharge points with similar field parameters 

were closely spaced, the one with the highest discharge rate 

was selected. Springs 1 and 11 are located at the toe of waste 

rock piles outside of the Level 5 and Elk Lode portals, respectively; they were chosen to characterize water that had filtered 

through this waste rock. Discharge at the Level 2 waste rock 

site passes through waste rock outside of the Level 2 portal, so 

it serves the same purpose. Spring 10 is located at the bottom 

of the meadow into which spring 1 water reinfiltrates shortly 

after discharging; water from spring 10 was collected to 

determine the degree to which the chemistry of spring 1 water 

changes after flowing as very shallow ground water through 

this meadow.

Three tributaries of Elk Creek (tributaries 1–3, fig. 5) 

were sampled to complement the spring samples. Tributaries 

1 and 2 collect water discharging from the northwest and 

Charge imbalance = 100 × (sum cations – sum anions)

(sum cations + sum anions)
Results 15

Elk Creek

Elk

Creek

Coal Creek

(EC-S3)

(EC-S4)

Spring 4

Spring 3

(EC-S2)

Spring 2

(EC-S5)

Spring 5

(EC-S1)

Spring 1

(EC-S10)

Spring 10 (EC-S11)

Spring 11

(EC-T1)

Tributary 1

(EC-T2)

Tributary 2 (EC-M11600)

Level 5 portal (EC-M11400B)

Elk Lode portal

(EC-S7)

Spring 7

(EC-T3)

Tributary 3

(EC-S9)

Spring 9

(EC-S8B)

Spring 8B

(EC-S8A)

Spring 8A

(EC-S12)

Spring 12

(EC-P4)

Pit 4 Pit 5 (EC-P5)

(EC-MUSTD1)

Level 2 waste rock

Level 1 portal (EC-MSTD1)

(EC-CELK1)

Elk Creek

(RW-S2)

Redwell Spring 2

(RW-S1)

Redwell Spring 1

(RW-W1)

Well 1

EXPLANATION

Sample site Portal of the Standard 

or Elk Mines

0

0 300 600 900 1,200 1,500 FEET

100 200 300 400 500 METERS

Redwell Basin

Elk Basin

Lower Elk Creek

N

Level 2 portal

Level 3 portal

Figure 5. Location of aboveground samples sites (white type; site ID in parentheses) within the three samples 

areas shown in figure 2. Blue regions, zones of diffuse spring discharge; red type, Standard Mine portal.
00 10 20 50 100 FEET 30 METERS EXPLA

N (EC-MSTDL31) Site 1 (EC-MSTDL32) Site 2 (EC-MSTDL33) Site 3 (EC-MSTDL34) Site 4 

Figure 6. Location of underground samples sites in Level 3 of Standard Mine (site ID in parentheses). Adapted from Colorado Division of Reclaand Safety (2007). min., mineralized or mineralization; wk. min., weakly mineralized.
0

0 10 20

50 100 FEET

30 METERS

EXPLA

N

(EC-M116002)

Site 2

Figure 7. Location of underground samples sites in Level 5 of Standard Mine (site ID in parentheses). Adapted from Colorado Division of Reclaand Safety (2007). min., mineralized or mineralization; wk. min., weakly mineralized.
18 Hydrogeochemical Investigation of the Standard Mine Vicinity, Upper Elk Creek Basin, Colorado

southeast sides, respectively, of a broad area of diffuse 

discharge between springs 2 and 5 (fig. 5). These two 

tributaries were therefore sampled to characterize ground 

water discharging within this zone. Similarly, tributary 3 

collects water discharging from a zone of multiple springs 

downhill from spring 7 (fig. 5); water from the tributary was 

collected to characterize this zone. 

Nine mine adits were observed, 3 dry and 6 draining 

water at estimated rates of 1–10 gpm. Four of the observed 

adits are part of the Standard Mine (Levels 1, 2, 3, and 5). 

At the time of task 2 sampling in August 2006, Levels 1 and 

5 were draining water and Levels 2 and 3 were dry. Of the 

observed adits, Level 1 had the highest estimated discharge 

rate, about 10 gpm, and the other adits discharged <5 gpm 

(typically <2 gpm). Adit lengths, aside from those associated 

with the Standard Mine, ranged from <20 ft to several tens 

of feet at least—sufficiently long that the end could not be 

seen from the portal. Three of the draining adits, the Level 1, 

Level 5, and Elk Lode portals, were selected as sampling sites 

(fig. 5). All adit discharge waters that were somewhat acidic 

(pH <6.0) or chemically evolved (specific conductance over 

about 100 μS/cm) were sampled. 

Eleven exploration pits, typically 5–10 ft deep and 

5–10 ft wide, were observed. Nine of the 11 contained water, 

and depth to water was 1–8 ft in all 9 pits. The flooded pits 

were all located on the basin floor, whereas the 2 dry pits were 

located uphill of the Level 5 portal on the basin headwall. 

Water in the pits was dilute (specific conductance 

<100 μS/cm) and had circumneutral pH (>5.5). Pits 4 and 

5 were selected as sample sites (fig. 5). Pit 4 was sampled 

because it appeared to contain the most intensely mineralized 

rock and is located on the Standard fault so, of all the observed 

pits, it was suspected to contain water with the highest metal 

concentrations. Pit 5 was sampled as a substitute for pit 4 after 

we learned that Colorado Division of Reclamation, Mining, 

and Safety personnel, about 4 h before sample collection, had 

entered Level 3 and then washed their muddy waders in pit 4. 

Ground water was not observed on the headwall of Elk 

Basin (on the ridges rimming the basin) but was observed only 

at the foot of the headwall or on the basin floor (fig. 5). This 

spatial distribution is the only trend apparent in ground-water 

occurrence and discharge. The greater density of sample points 

near the Standard and Elk faults is a function of the mining 

activity there (and the desire to characterize waters potentially 

affected by that activity), not of a greater density of groundwater discharge points.

As part of the survey of ground-water discharge locations, outcrop-scale faults, veins, and mineralization were also 

noted. As expected, the adits and pits are commonly associated with faults and veins, the loci of mineralized rock. These 

faults, veins, and silicified zones generally trend either east to 

east-northeast or north to north-northwest. Sulfide minerals 

including pyrite, sphalerite, galena, and chalcopyrite are the 

most abundant in outcrops and waste rock located along the 

Standard fault and in the breccia pipe in Redwell Basin (unit f 

in fig. 3). These sulfide minerals are also present, although in 

lower abundance, in outcrops and waste rock at the Elk Lode 

portal. The Elk Lode portal is located within (and apparently 

follows) a well-defined, mineralized fault similar in scale and 

orientation to exposed sections of the Standard fault. This fault 

is located within about 200 ft of the mapped location of the 

Elk fault (fig. 3). It thus may be a splay or conjugate of the Elk 

fault, or perhaps the Elk fault itself if the mapped location is 

slightly off. Sulfide minerals are considerably less abundant in 

outcrops and waste rock in locations other than the Standard 

fault, Elk Lode portal, and Redwell Basin breccia pipe. Outside of these areas, mineralization takes the form of sparsely 

disseminated and veinlet pyrite. Springs generally emanate 

from float, so the bedrock geology at the spring locations 

could not be observed.

In addition to the Elk Basin sites, three sample sites were 

selected in Redwell Basin, the basin adjacent to the northeast 

(fig. 5). Redwell spring 1 was chosen because it was the 

ground-water discharge location closest to being on-trend with 

the Standard fault, yet outside of the zone of intense alteration 

associated with the breccia pipe exposed in Redwell Basin 

(fig. 8). The purpose of this sample site was to determine if 

mineralized rock in the Standard fault might be influencing 

ground water in Redwell Basin. Redwell spring 2, also known 

as “The Red Well,” was selected because the large volume of 

ferricrete deposited by the spring and its low dissolved-oxygen 

concentration suggest that this water may have circulated more 

deeply and be older than other ground water in the Standard 

Mine vicinity. The purpose of this sample was therefore to 

characterize the older, more deeply circulating component 

of ground water in the area. Well 1 is an uncapped mineral 

exploration drill hole that forms an artesian well flowing at 

an estimated rate of 10–20 gpm. Extensive Fe oxide deposits 

(rust-colored strand extending northward from the well in 

fig. 5) and a low dissolved-oxygen concentration suggest 

that water from well 1, like that from Redwell spring 2, is 

deep-circulating and older. However, sampling conditions for 

dissolved gases were better at well 1 than at Redwell spring 

2; the focused, rapidly discharging water was free of bubbles, 

whereas bubbles were visible in the more slowly emerging 

water at Redwell spring 2, suggesting some gas loss in the 

large spring pool. A sample for dissolved gas and 3H was 

therefore collected at well 1 to more confidently characterize 

the age of what appeared to be the oldest component of ground 

water in the area. 

Underground Observations and Sample Site 

Selection 

Levels 3 and 5 of the Standard Mine (fig. 4) were entered 

with Colorado Division of Reclamation, Mining, and Safety 

personnel in August 2006 as part of task 3 in order to make 

hydrologic and geologic observations, select sample sites, 

and collect water samples. Collapses at or near the portals 

of Levels 1 and 2 prevented entry into these tunnels. A 

draft underground assessment report by Colorado Division 
Results 19

Qt

Level 1 portal Qt

Level 2 portal

Level 3 portal

Level 5 portal

Standard Fault

Elk Fault

Redwell

Basin

Elk Lode portal Tributary 1

Tributary 2

Tributary 3

Spring 1

Spring 2

Spring 3

Spring 4

Spring 5

Spring 7

Spring 8A

Spring 8B

Spring 9

Spring 10

Spring 11

Spring 12

Redwell

Spring 1

Redwell

Spring 2

Well 1

Pit 4 Pit 5

Level 2

waste rock

0 300 600 900 1,200 1,500 FEET

0 100 200 300 400 500 METERS

Propylitically

or phyllically

altered

rocks

38°53’

38°53’30”

107°04’30” 107°04’ 107°03’30”

Sample site

Qt

Tw

Ql

Toc

Quaternary talus

deposit

Kmv

Quaternary landslide

deposit

Tertiary Wasatch

Formation

Tertiary Ohio

Creek Formation

Cretaceous 

Mesaverde Formation

qmp Tertiary quartz

monzonite porphyry

f Tertiary felsite

EXPLANATION

Contact—Dashed where approximately

 located

Fault or shear zone—Dashed 

 where inferred. U, upthrown

 side; D, downthrown side.

U

D

16 Strike and dip of beds

Mine adit

Contour interval = 40 ft

Extent of alteration zone

Figure 8. Location of aboveground sample sites (black filled circles) in relation to geology. Blue regions, zones 

of diffuse spring discharge; white type, Standard Mine portal. Geology from Gaskill and others (1967). Base map is 

U.S. Geological Survey 1:24,000 topographic map of Oh-Be-Joyful, Colo. (1973).
20 Hydrogeochemical Investigation of the Standard Mine Vicinity, Upper Elk Creek Basin, Colorado

of Reclamation, Mining, and Safety (2007) describes in 

detail tunnel features (such as layout, raises, and stopes) and 

geology. Tunnel features relevant to the hydrogeologic system 

and sample site selection are discussed below.

Level 3 follows the Standard fault along nearly the entire 

tunnel (fig. 6). The fault zone is typically 3–5 ft wide, contains sulfide mineralization, strikes N. 70°–80° E. and dips 

50°–70° E. No discrete inflows were observed. Instead, water 

entered the tunnel by dripping from the ceiling and walls. The 

fault zone material (gouge and breccia) in the ceiling appeared 

to be the primary source of the inflowing water, which dripped 

to the floor or trickled down the footwall (northwest) side of 

the tunnel where the footwall surface formed the northwest 

wall of the tunnel. Therefore, the footwall (northwest) side of 

the tunnel was commonly wet, and the hanging-wall (southeast) side of the tunnel was commonly dry. The dripping was 

pervasive throughout the tunnel, though its intensity varied. 

No obvious correlations were noted between zones of more 

intense dripping and geologic features. Water was on the floor 

throughout the tunnel, but flow was either nonexistent or 

imperceptibly slow. Water flowed down the two raises to Level 

2 on both the outby (portal) side and inby (tunnel end) side of 

each raise, indicating at least some inward and outward flow 

on the tunnel floor toward the raises.

Five sample sites were selected in Level 3 (fig. 6). Sites 

1 and 2 were chosen because of the relatively low pH values 

(<5) of their water and to characterize water flowing toward 

and down the first raise from outby and inby sides, respectively. Site 3 was chosen because it was the location of the 

most intense dripping. Site 4 was chosen to characterize water 

flowing toward and down the second raise from the inby side. 

Site 5 was chosen to characterize inflow at the end of the tunnel. The sample from site 3 was collected directly from water 

dripping into the tunnel. Samples from the remainder of the 

sites were collected from water on the tunnel floor and thus 

integrate local and upstream inflows (indby or outby, depending on the site).

Level 5 also follows the Standard fault, or segments 

of the fault, along most of the length of the tunnel (fig. 7). 

Exposed fault zones are typically 1–4 ft wide, contain sulfide 

minerals, strike N. 65°–85° E., and dip 60°–80° E. As with 

Level 3, water entered the tunnel pervasively as diffuse drips 

and we observed no discrete inflows. Also as with Level 3, 

the fault zone material appeared to be the primary source of 

inflowing water, resulting in the footwall (northwest) side of 

the tunnel commonly being wet and the hanging-wall (southeast) side commonly being dry when the footwall surface 

formed the northwest wall of the tunnel. Two cross faults 

striking approximately perpendicular to Standard fault segments were observed, both 1–2 ft wide and dipping 80°–85° 

W. Water dripped from material within these faults, as with 

the Standard fault segments, but no increase in tunnel inflows 

were noted near these cross faults. No correlations were noted 

between the rate of dripping and geologic features in the tunnel. Water was on the floor throughout the tunnel and flowed 

slowly toward the portal (no raises are present).

Two sample sites were selected in Level 5 (fig. 7). Site 1 

at the end of the accessible portion of the tunnel was chosen to 

characterize inflow at this point and inby the collapse blocking 

the tunnel. The sample was collected from a pool at the base 

of the collapse. Site 2 was selected because it was the largest 

single inflow (but still <0.2 gpm), in the form of a thin stream 

of water spouting from the ceiling apparently under pressure. 

The sample was collected directly from the inflow.

Field Parameters

Measured field parameters included pH, redox potential, 

discharge temperature, dissolved oxygen, and specific conductance (appendix 2). Temperature, dissolved oxygen, and specific conductance were measured for all samples except those 

collected as part of task 1 in winter and early spring, when 

snow cover made accurate dissolved oxygen measurements 

unfeasible. Eh and pH were not remeasured for samples collected within a week of a previous sample at the same site. Eh 

was measured only on selected samples to observe representative Eh values for the site. Only pH and specific conductance 

measurements are discussed below because these parameters 

are typically the best indicators of metal-rich waters.

Task 1

Values of pH ranged from 3.4 to 6.7 at the Level 1 portal, 

and from 6.1 to 7.4 at Elk Creek, spring 2, and spring 8A 

(fig. 9A). Measurements at Elk Creek and the Level 1 portal showed the same general seasonal trend of climbing or 

remaining similar through summer, fall, and winter; peaking 

in late winter to early spring (during base flow); then dropping during the spring snowmelt runoff. The pattern was more 

muted for Elk Creek than for the Level 1 portal. Measurements 

at springs 2 and 8A in the late summer, fall, and spring showed 

little variation. Specific conductance measurements ranged 

from 442 to 613 μS/cm at the Level 1 portal and from 52 

to180 μS/cm at Elk Creek, spring 2, and spring 8A (fig. 9B). 

As with pH, specific conductance measurements at Elk Creek 

and the Level 1 portal showed the same general seasonal trend 

of climbing or remaining similar through summer, fall, and 

winter; peaking in late winter; then dropping during the spring 

snowmelt runoff. However, the seasonal variation in specific 

conductance was less pronounced than variation in pH. Again, 

measurements at springs 2 and 8A in late summer, fall, and 

spring showed relatively little seasonal variation. No data were 

collected from springs 2 and 8A during the period of greatest 

variation in specific conductance and pH at the Level 1 portal 

and Elk Creek (late February through early June), owing to 

an inability to access the springs under the snowpack. Therefore, pH and specific conductance at the spring sites may have 

varied seasonally in a manner similar to the Level 1 portal and 

Elk Creek, but this possible variation cannot be resolved by 

the data. 
Results 21

Figure 9. pH (A) and specific conductance (B) at task 1 sample sites plotted 

versus sample date.

3.0

3.5

4.0

4.5

5.0

5.5

6.0

6.5

7.0

7.5

8.0

7/1/06 8/31/06 10/31/06 12/31/06 3/2/07 5/2/07 7/2/07

0

100

200

300

400

500

600

700

7/1/06 8/31/06 10/31/06 12/31/06 3/2/07 5/2/07 7/2/07

pH

SAMPLE DATE

Level 1 portal

Elk Creek

Spring 2

Spring 8A

SPECIFIC CONDUCTANCE, IN MICROSIEMENS 

PER CENTIMETER

SAMPLE DATE

A

B

Level 1 portal

Elk Creek

Spring 2

Spring 8A
22 Hydrogeochemical Investigation of the Standard Mine Vicinity, Upper Elk Creek Basin, Colorado

Task 2

Field pH and specific conductance at the aboveground 

sample sites are shown in figures 10 and 11, respectively. 

Measured pH values were generally circumneutral (6.2–7.7) 

except at sites near the Standard fault, where they were as low 

as 3.0, and at Redwell spring 2 (3.7). Mineralized rocks in the 

Standard fault and the breccia pipe immediately upgradient of 

Redwell spring 2 contain the most abundant sulfide minerals 

observed in the study area. The two lowest pH values were 

measured at the Level 2 waste rock site and at spring 1, both 

locations of waste-rock discharge. Of the sites with circumneutral waters located away from the Standard fault, those 

near the Elk Lode portal, another location of mineralized rock 

relatively high in sulfides, had the lowest pH values (6.2–6.3).

Measured specific conductance values were generally low 

(30–108 μS/cm) except in three instances: (1) sites near the 

Standard fault, where they were as high as 840 mS/cm; 

(2) well 1 and Redwell spring 2 (618 and 249 μS/cm, respectively); and (3) springs in the area of diffuse discharge south 

of the Level 1 portal (180–230 μS/cm). The two highest SC 

values (773 and 840 μS/cm) were measured at locations 

having the two lowest pH values (Level 2 waste rock site and 

spring 1), suggesting that specific conductance is controlled by 

pH or by factors that also control pH (mineralogy and redox 

conditions). However, specific conductance values were also 

elevated (>180 μS/cm) at some locations where the water was 

circumneutral, namely the Levels 1 and 5 portals and the area 

of diffuse discharge south of the Level 1 portal. The fact that 

water from the Levels 1 and 5 portals is expected to be some 

of the oldest at the site, because these tunnels penetrate deeply 

into the subsurface, suggests that specific conductance may 

also be controlled by ground-water residence time.

Task 3

Figures 12 and 13 show pH and specific conductance 

values measured at the underground sites. Measured pH values 

were circumneutral (6.7–7.2) in both tunnels except at Level 3 

sites 1 and 2 (4.3 and 3.3, respectively). Specific conductance 

values at the underground sites ranged from 153 to 424 μS/cm. 

As with the aboveground samples, the highest specific conductance value was measured at the location with the lowest 

pH (Level 3 site 2).

Clearly apparent, systematic variations in geology were 

not observed in Levels 3 or 5 or at the surface above these 

tunnels, suggesting that systematic relationships between 

the chemistry and overburden thickness for the underground 

samples are probably not caused by such geologic variations 

(fig. 14). A more likely explanation is that the residence time 

of ground water at the underground sites generally increases 

with overburden thickness. The specific conductance data 

along with other data in following sections are therefore 

plotted against overburden thickness to evaluate potential 

relationships between ground-water residence time and 

chemistry. Of course, flow paths can be highly irregular 

and flow rates highly heterogeneous in fractured-rock 

ground-water-flow systems, so a strong correlation between 

overburden and residence time is not expected. Nevertheless, 

the broad range of overburden thicknesses for the underground 

sites (50–350 ft) means that flow pathway lengths and 

residence times on average should be longer for the deeper 

sites than for the shallower sites. Further, assuming a rough 

correlation between overburden thickness and residence 

time is reasonable given that ground water was not observed 

entering Levels 3 and 5 by discrete fracture-controlled inflows 

(clearly indicative of highly variable flow rates to the tunnel) 

but, instead, by pervasive and diffuse dripping from gouge 

and breccia in the Standard fault zone (consistent with more 

uniform flow contained largely within the Standard faultzone material). Aside from the two samples with the thinnest 

overburden having the lowest pH values, pH varied little 

with overburden thickness (fig. 14A). However, if Level 3 

site 2 is considered an outlier, specific conductance generally 

increased with overburden thickness (fig. 14B). Similar to the 

aboveground data, the underground specific conductance data 

therefore suggest that specific conductance is controlled in 

part by residence time.

Major Ion and Trace Element Chemistry

Fifty samples were analyzed for major and trace element 

chemistry (appendixes 3 and 4). Most major, minor, and trace 

element replicate concentrations were within ±10 percent 

of the value obtained for the corresponding original sample. 

Analytical results for equipment blanks (appendixes 3 and 4) 

and are designated as EB–01 through EB–05. All analytes in 

the equipment blanks were below analytical detection limits 

except for bicarbonate alkalinity, which was consistently measured at 2 mg/L, just above the reporting limit. Good agreement between ICP–AES and ICP–MS results was observed 

for cations measured at concentrations at least three times the 

detection limit (fig. 15). The percent-charge imbalance was 

low (less than 10 percent) for all samples (appendix 3).

Discussion of results of major ion and trace element 

analyses in this report focuses on calcium (Ca), sulfate 

(SO4), zinc (Zn), lead (Pb), cadmium (Cd), copper (Cu), and 

manganese (Mn). Calcium and SO4 were chosen because they 

were typically the most abundant major cation and anion, 

respectively, and their spatial and temporal trends generally 

represented the trends of other major ions. Nine contaminants 

of concern were identified in a recent ecological risk 

assessment of the site (Syracuse Research Corporation, 2007): 

Zn, Pb, Cd, Cu, Mn, aluminum, silver, nickel, and calcium. 

Of these, concentrations Zn, Pb, Cd, Cu, and Mn exceeded 

water quality standards in the Elk Creek samples collected 

as part of this study, so these five metals are discussed in 

this report. Water quality standards for Elk Creek (segment 

11, upper Gunnison River Basin) were computed from table 

value standard equations for chronic exposure specified in 

the Colorado Department of Public Health and Environment 
Results 23

Elk Creek

Elk

Creek

Coal Creek

7.7

7.7

3.2

6.9

6.7

7.4

6.2

7.2

7.1

7.4

6.4

4.7

6.2

7.3

5.6

5.8

6.2

3.0

6.7 6.3

6.7

3.7

7.2

EXPLANATION

<4

4–5

5–6

6–7

>7

7.0

0 Field pH

0 300 600 900 1,200 1,500 FEET

100 200 300 400 500 METERS

Redwell Basin

Elk Basin

Lower Elk Creek

Level 5 portal

Level 1 portal

Level 2 portal

Level 3 portal

N

Elk Lode portal

Figure 10. pH (white type) at aboveground sample sites. Blue regions, zones of diffuse spring discharge; 

red type, Standard Mine portal.
24 Hydrogeochemical Investigation of the Standard Mine Vicinity, Upper Elk Creek Basin, Colorado Elk Creek

Elk

Creek

Coal Creek

30

86

840

91

63

108

56

72

180

180

109

187

57

230

47

78

518

773

88 215

75

249

618

132

52

Elk Lode portal

Redwell Basin

Elk Basin

Lower Elk Creek

Level 5 portal

Level 1 portal

Level 2 portal

Level 3 portal

N

EXPLANATION

<100

100–200

200–400

400–600

>600

Field specific conductance, in 

0 microsiemens per centimeter

0 300 600 900 1,200 1,500 FEET

100 200 300 400 500 METERS

Figure 11. Specific conductance (white type) at aboveground sample sites. Blue regions, zones of diffuse 

spring discharge; red type, Standard Mine portal.
0

0 10 20 30 METERS

50 100 FEET

EXP

N

pH = 4.29SC = 178 S/cm

pH = 3.26SC = 424 S/cm

pH = 6.95SC = 153 S/cm

pH = 6.95SC = 188 S/cm

SC Specific condu

Figure 12. Field parameters at underground sample sites in Level 3 of Standard Mine. Adapted from Colorado Division of Reclamation, MiningSafety (2007). min., mineralized or mineralization; wk. min., weakly mineralized.
0 10 20 0 50 100 FEET 30 METERS EXPL

N pH = 7.20 SC = 241 S/cm 

Figure 13. Field parameters at underground sample sites in Level 5 of Standard Mine. Adapted from Colorado Division of Reclamation, Mining(2007). min., mineralized or mineralization.
Results 27

Figure 14. pH (A) and specific conductance (B) of underground samples plotted versus overburden thickness.

Water Quality Control Commission Regulation Number 35 

(5 CCR 1002–35), Classifications and Numeric Standards 

for Gunnison and Lower Dolores River Basins. Table value 

standards are computed from a water hardness value. The 

hardness value used was the average hardness of the eight 

samples collected from Elk Creek as part of this study 

(47.4 mg/L as calcium carbonate, appendix 3). Computed 

water quality standards for Elk Creek are Zn, 0.066 mg/L; 

Pb, 0.0011 mg/L; Cd, 0.00024 mg/L; Cu, 0.0047 mg/L; and 

Mn, 0.050 mg/L. Note that the Mn standard is the value 

specified for surface waters used for water supply. No nickel 

concentrations measured in this study exceeded the water 

quality standard for Elk Creek (0.028 mg/L). Aluminum and 

Ca are not discussed as contaminants in this report because 

no appropriate water quality standards were found for these 

constituents. Silver is not discussed because its detection limit 

(0.001 mg/L) exceeds the water quality standard for Elk Creek 

(0.00002 mg/L). Unless noted otherwise, all references to 

chemical constituent concentrations below are to the dissolved 

concentration (measured in filtered samples) rather than to 

total concentration (measured in unfiltered samples).

Task 1

At the Level 1 portal, Ca concentrations in the time-series 

samples ranged from 38.7 to 83.2 mg/L and SO4 concentrations from 166 to 280 mg/L (fig. 16). Calcium and SO4

concentrations were lower at Elk Creek spring 2 and spring 

8A; they ranged from 6.69 to 28.9 mg/L and from 12.8 to 

46.7 mg/L, respectively. Concentrations at Elk Creek and the 

Level 1 portal showed the same general seasonal trend as specific conductance (fig. 9B)—increasing through summer, fall, 

and winter; peaking in late winter at base flow; then decreasing during the spring snowmelt runoff. Again as with specific 

conductance, concentrations at springs 2 and 8A showed relatively little seasonal variation, although at spring 2 they were 

slightly lower in the spring than in the summer and fall.

Seasonal concentrations of all five metals consistently 

exceeded water quality standards for Elk Creek at the Level 

1 portal (fig. 17). Zn ranged from 18.3 to 26.3 mg/L, Pb from 

0.101 to1.70 mg/L, Cd from 0.121 to 0.155 mg/L, Cu from 

0.0826 to 0.801 mg/L, and Mn from 5.62 to 10.6 mg/L. Metals 

concentrations at Elk Creek were an order of magnitude or 

more below those at the Level 1 portal; Zn ranged from 0.428 

to 0.986 mg/L, Pb from 0.0003 to 0.0066 mg/L, Cd from 

0.00220 to 0.00517 mg/L, Cu from 0.0018 to 0.0124 mg/L, 

and Mn from 0.0072 to 0.175 mg/L. Zinc and Cd at Elk Creek 

consistently exceeded water-quality standards, whereas the 

other three metals exceeded water quality standards during 

only part of the year, commonly in the spring. Metals concentrations were typically lower still at springs 2 and 8A and 

generally remained near or below water-quality standards for 

Elk Creek. Lead and Cu concentrations at the Level 1 portal 

and at Elk Creek displayed a pronounced increase during 

spring snowmelt runoff, mirroring the pronounced decrease in 

pH (fig. 9A), and they reached their highest concentrations of 

2

3

4

5

6

7

8

0 100 200 300 400

50

100

150

200

250

300

350

400

450

0 100 200 300 400

Level 3

Level 5

pH

OVERBURDEN THICKNESS,

IN FEET

Level 3

Level 5

SPECIFIC CONDUCTANCE, IN 

MICROSIEMENS PER CENTIMETER

OVERBURDEN THICKNESS,

IN FEET

A B
28 Hydrogeochemical Investigation of the Standard Mine Vicinity, Upper Elk Creek Basin, Colorado

0 10

10

20

30

40

50

20 30 40 50

0

0 100 200 300 400 500 600 700 800

0

0 5,000 10,000 15,000 20,000 25,000

0

5,000

10,000

15,000

20,000

25,000

Barium

Strontium

A

Manganese

B

C

ICP–AES, IN MICROGRAMS PER LITER

ICP–AES, IN MICROGRAMS PER LITER

ICP–AES, IN MICROGRAMS PER LITER

ICP–MS, IN MICROGRAMS PER LITER 

ICP–MS, IN MICROGRAMS PER LITER 

ICP–MS, IN MICROGRAMS PER LITER 

100

200

300

400

500

600

700

800

Figure 15. Comparison of analytical results by using ICP–AES 

(inductively coupled plasma–atomic emission spectroscopy) 

and ICP–MS (inductvely coupled plasma–mass spectrometry). 

Barium (A), manganese (B), and strontium (C) concentration. 

Solid diagonal line, 1:1 correspondence; dashed line, 10 percent 

variation.
Results 29

 Figure 16. Calcium (A) and sulfate (B) concentration at task 1 sample sites plotted versus sample date. Only samples with 

concentrations above detection limits are shown.

the year in May or early June. At Elk Creek, Zn, Cd, and Mn 

concentrations also increased sharply during spring runoff, 

although high concentrations were also observed in the fall. At 

the Level 1 portal, Zn, Cd, and Mn concentrations increased 

between the May 5 and May 15, 2007, sampling events, but 

this increase was superimposed on an overall trend of decreasing concentration through the spring, similar to the trend of 

major ion concentrations. Concentrations of all five metals 

showed relatively minor seasonal variations at springs 2 and 

8A. 

Task 2

Concentrations of chemical constituents at the 

aboveground sample sites varied spatially as well as 

temporally (figs. 18–24). Calcium and SO4 concentrations 

(figs. 18 and 19) ranged from 4.09 to 60.4 mg/L and from 

2.99 to 318 mg/L, respectively, and had a distribution similar 

to specific conductance (fig. 11). Higher concentrations of 

Ca and SO4 occurred in discharge from tunnels and waste 

rock associated with the Standard Mine, in samples from the 

zone of diffuse discharge south of the Level 1 portal, and at 

Redwell spring 2 (SO4 only). Zinc concentrations (fig. 20) 

ranged from 0.0005 to 25.6 mg/L, Pb concentrations (fig. 

21) from <0.00005 to 1.73 mg/L, Cd concentrations (fig. 22) 

from <0.00002 to 0.197 mg/L, Cu concentrations (fig. 23) 

from <0.0005 to 1.08 mg/L, and Mn concentrations (fig. 24) 

from <0.0002 to 23.5 mg/L. Concentrations of all five metals 

commonly exceeded water quality standards for Elk Creek at 

sites located along the Standard fault, near the Elk Lode portal, 

and in Redwell Basin. Elsewhere, metals concentrations 

seldom exceeded water quality standards for Elk Creek and 

were typically near detection limits. Metals concentrations 

typically were highest at locations of tunnel and waste rock 

discharge associated with the Standard and Elk Lode Mines 

and at Redwell spring 2. The distribution of these metals 

therefore generally mirrored the pH distribution (fig. 10).

Task 3

Concentrations of chemical constituents at the 

underground sample sites also varied similarly (figs. 25 

and 26). Calcium and SO4 concentrations ranged from 11.1 

to 38.4 mg/L and from 31.7 to 111 mg/L, respectively. 

Zinc concentrations ranged from 0.556 to 7.70 mg/L, Pb 

concentrations from 0.0012 to 2.19 mg/L, Cd concentrations 

from 0.00008 to 0.112 mg/L, Cu concentrations from <0.0005 

to 1.67 mg/L, and Mn concentrations from 0.0133 to 4.38 

mg/L. With the exception of Mn, metal concentrations were 

generally higher in Level 3 than in Level 5, and were typically 

the highest at sites 1 and 2 in Level 3, the two sites with the 

lowest pH. The concentrations of some chemical constituents 

bore some relation to overburden thickness (figs. 27 and 28). 

Similar to specific conductance (fig. 14), Ca and SO4 generally 

increased with overburden thickness, the main exception 

being SO4 at Level 3 site 2 (fig. 27). However, similar to pH 

(fig. 14), metal concentrations showed little correlation with 

overburden thickness aside from concentrations at the two 

Level 1 portal

Elk Creek

Spring 2

Spring 8A

Level 1 portal

Elk Creek

Spring 2

Spring 8A

A B

7/1/06 8/31/06 10/31/06 12/31/06 3/2/07 5/2/07 7/2/07 7/1/06 8/31/06 10/31/06 12/31/06 3/2/07 5/2/07 7/2/07

SAMPLE DATE SAMPLE DATE

0

50

100

150

200

250

300

SO4, IN MILLIGRAMS PER LITER

10

20

30

40

50

60

70

80

90

Ca, IN MILLIGRAMS PER LITER

0
30 Hydrogeochemical Investigation of the Standard Mine Vicinity, Upper Elk Creek Basin, Colorado

0.016

0.3

0.6

0.9

1.2

1.5

1.8

0.03

0.06

0.09

0.12

0.15

0.18

5

10

15

20

25

30

0.2

0.4

0.6

0.8

1.0

2

4

6

8

10

12

0

0.004

0.008

0.012

0.020

7/1/06 8/31/06 10/31/06 12/31/06 3/2/07 5/2/07 7/2/07

0

0.001

0.002

0.003

0.004

0.005

0.006

7/1/06 8/31/06 10/31/06 12/31/06 3/2/07 5/2/07 7/2/07

0

0.2

0.4

0.6

0.8

1.0

1.2

7/1/06 8/31/06 10/31/06 12/31/06 3/2/07 5/2/07 7/2/07

0

0.004

0.008

0.012

0.016

0.020

0.024

7/1/06 8/31/06 10/31/06 12/31/06 3/2/07 5/2/07 7/2/07

0

0.04

0.08

0.12

0.16

0.20

7/1/06 8/31/06 10/31/06 12/31/06 3/2/07 5/2/07 7/2/07

SAMPLE DATE

Zn, IN MILLIGRAMS PER LITER Cd, IN MILLIGRAMS PER LITER

Cu, IN MILLIGRAMS PER LITER Pb, IN MILLIGRAMS PER LITER

SAMPLE DATE

Standard = 0.066 milligrams per liter Standard = 0.0011 milligrams per liter

Standard = 0.0047 milligrams per liter

Standard = 0.00024 milligrams per liter

A B

C D

Level 1 portal

Elk Creek

Spring 2

Spring 8A

Level 1 portal

Elk Creek

Spring 2

Mn, IN MILLIGRAMS PER LITER

SAMPLE DATE

SAMPLE DATE

Standard = 0.050 milligrams per liter

E

Level 1 portal

Elk Creek

Spring 2

Spring 8A

Level 1 portal

Elk Creek

Spring 2

Level 1 portal

Elk Creek

Spring 2

Spring 8A

SAMPLE DATE

Figure 17. Zinc (A), lead (B), cadmium (C), copper (D), and 

manganese (E) concentration at task 1 sample sites plotted 

versus sample date. Only samples with concentrations above 

detection limits are shown. Dashed horizontal line marks water 

quality standard for Elk Creek (see text).
Results 31

Elk Creek

Elk

Creek

Coal Creek

4.5

10.9

8.2

36.5

11.3

9.1

17.2

8.7

11.1

28.9

28.8

16.1

17.3 7.2

38.4

4.4

7.9

60.4

18.7

25.5

10.3

10.2

4.09

20.9

<10

10–20

20–30

>30

Redwell Basin

Elk Basin

Lower Elk Creek

Level 5 portal

Level 1 portal

Level 2 portal

Level 3 portal

Elk Lode portal

N

EXPLANATION

Ca concentration, 

 in milligrams per liter 0

0 300 600 900 1,200 1,500 FEET

100 200 300 400 500 METERS

Figure 18. Calcium concentration (white type) at aboveground sample sites. Blue regions, zones of diffuse spring 

discharge; red type, Standard Mine portal.
32 Hydrogeochemical Investigation of the Standard Mine Vicinity, Upper Elk Creek Basin, Colorado Elk Creek

Elk

Creek

Coal Creek

N

EXPLANATION

SO4 concentration, in 

 milligrams per liter

0

0 300 600 900 1,200 1,500 FEET

100 200 300 400 500 METERS

2.99

21.8

3.61

318

25.7

11.9

20.0

5.90

7.67

46.7

45.4

34.2

73.0

17.8

65.6

16.2

27.5

232

183

24.4 81.1

25.4

81.5

25.1

<10

10–30

30–100

>100

Redwell Basin

Elk Basin

Lower Elk Creek

Level 5 portal

Level 1 portal

Level 2 portal

Level 3 portal

Elk Lode portal

Figure 19. Sulfate concentration (white type) at aboveground sample sites. Blue regions, zones of diffuse 

spring discharge; red type, Standard Mine portal.
Results 33

Elk Creek

Elk

Creek

Coal Creek

N

EXPLANATION

Zn concentration, in milligrams per liter 0

0 300 600 900 1,200 1,500 FEET

100 200 300 400 500 METERS

0.0074

0.0313

0.0033

25.6

0.102

0.0026

0.0012

0.0147

0.0005

0.0024

0.0011

0.198

3.40

0.883

0.0020

0.166 0.752

24.1

24.4

3.10

3.06

0.148

5.76

0.428

<0.005

0.005–0.066

0.066–1.0

>1.0

Redwell Basin

Elk Basin

Lower Elk Creek

Level 5 portal

Level 1 portal

Level 2 portal

Level 3 portal

Elk Lode portal

Figure 20. Zinc concentration (white type) at aboveground sample sites. Orange symbols mark sites at 

which zinc concentration exceeds water quality standard for Elk Creek of 0.066 mg/L (see text). Blue regions, 

zones of diffuse spring discharge; red type, Standard Mine portal.
34 Hydrogeochemical Investigation of the Standard Mine Vicinity, Upper Elk Creek Basin, Colorado Elk Creek

Elk

Creek

Coal Creek

0.00087

0.00009

0.0004

1.16

0.0001

<0.00005

0.00006

0.0043

<0.00005

0.0004

0.0002

0.0001

0.219

0.0957

0.0014

0.357 0.0171

0.654

0.604

0.0142 0.480

0.0015

1.73

0.0004

<0.0001

0.0001–0.0011

0.0011–0.1

>0.1

Redwell Basin

Elk Basin

Lower Elk Creek

Level 5 portal

Level 1 portal

Level 2 portal

Level 3 portal

Elk Lode portal

N

EXPLANATION

Pb concentration, in milligrams per liter 0

0 300 600 900 1,200 1,500 FEET

100 200 300 400 500 METERS

Figure 21. Lead concentration (white type) at aboveground sample sites. Orange symbols mark sites 

at which zinc concentration exceeds water quality standard for Elk Creek of 0.0011 mg/L (see text). Blue 

regions, zones of diffuse spring discharge; red type, Standard Mine portal.
Results 35

Elk Creek

Elk

Creek

Coal Creek

N

EXPLANATION

Cd concentration, in milligrams per liter 0

0 300 600 900 1,200 1,500 FEET

100 200 300 400 500 METERS

0.00006

0.00012

0.00002

0.197

0.00052

<0.00002

<0.00002

0.00006

<0.00002

<0.00002

<0.00002

0.00038

0.0262

0.00553

<0.00002

0.00071 0.00482

0.151

0.190

0.0245

0.0171

0.00220

0.00070

0.0540

<0.00002

0.00002–0.00024

0.00024–0.02

>0.02

Redwell Basin

Elk Basin

Lower Elk Creek

Level 5 portal

Level 1 portal

Level 2 portal

Level 3 portal

Elk Lode portal

Figure 22. Cadmium concentration (white type) at aboveground sample sites. Orange symbols mark sites at 

which cadmium concentration exceeds water quality standard for Elk Creek of 0.00024 mg/L (see text). Blue 

regions, zones of diffuse spring discharge; red type, Standard Mine portal.
36 Hydrogeochemical Investigation of the Standard Mine Vicinity, Upper Elk Creek Basin, Colorado Elk Creek

Elk

Creek

Coal Creek

N

EXPLANATION

0 Cu concentration, in milligrams per liter

0 300 600 900 1,200 1,500 FEET

100 200 300 400 500 METERS

<0.0005

<0.0005

<0.0005

0.625

<0.0005

<0.0005

<0.0005

<0.0005

<0.0005

<0.0005

<0.0005

<0.0005

0.0388

0.0062

<0.0005

<0.0005

<0.0005

0.225

1.08

0.0016

0.0834

<0.0005

0.0005–0.0047

0.0047–0.05

>0.05

0.0020

<0.0005

0.0048

Redwell Basin

Elk Basin

Lower Elk Creek

Level 5 portal

Level 1 portal

Level 2 portal

Level 3 portal

Elk Lode portal

Figure 23. Copper concentration (white type)at aboveground sample sites. Orange symbols mark sites at 

which copper concentration exceeds water quality standard for Elk Creek of 0.0047 mg/L (see text). Blue 

regions, zones of diffuse spring discharge; red type, Standard Mine portal.
Results 37

Elk Creek

Elk

Creek

Coal Creek

N

EXPLANATION

Mn concentration, in milligrams per liter 0

0 300 600 900 1,200 1,500 FEET

100 200 300 400 500 METERS

0.0173

0.0104

0.0271

23.5

<0.0002

<0.0002

<0.0002

0.106

0.0003

0.0007

0.0006

0.0082

0.782

0.0066

0.0006

0.0810 0.305

10.1

5.38

2.27

0.331

<0.005

0.005–0.05

0.05–0.5

>0.5

0.0129

0.0051

1.36

Redwell Basin

Elk Basin

Lower Elk Creek

Level 5 portal

Level 1 portal

Level 2 portal

Level 3 portal

Elk Lode portal

Figure 24. Manganese concentration (white type) at aboveground sample sites. Orange symbols mark sites 

at which manganese concentration exceeds water quality standard for Elk Creek of 0.05 mg/L (see text). Blue 

regions, zones of diffuse spring discharge; red type, Standard Mine portal.
Figure 25. Concentrations of calcium, sulfate, and selected metals at underground sample sites in Level 3 of Standard Mine. Adapted from ColoDivision of Reclamation, Mining, and Safety (2007). min., mineralized or mineralization; wk. min., weakly mineralized.

0

0 10 20

50 100 FEET

30 METERS

EXP

N

All concentrations in  Sample site

Ca = SO4 = 

Zn = Pb = Cd = Cu = Mn = 

Ca = SO4 = 

Zn = Pb = Cd = Cu = Mn = 

Ca = SO4 = 

Zn = Pb = Cd = Cu = Mn = 

Ca = SO4 = 

Zn = Pb = Cd = Cu = Mn = 

11.161.0

5.341.770.0348

0.3401.56

19.1

111

7.702.19

0.1121.67

0.989

20.2

31.7

1.070.09470.007270.1110.0133

27.258.6

1.980.0518

0.0218

0.0536

0.236
Figure 26. Concentrations of calcium, sulfate, and selected metals at underground sample sites in Level 5 of the Standard Mine. Adapted from Division of Reclamation, Mining, and Safety (2007). min., mineralized or mineralization.

0

0 10 20

50 100 FEET

30 METERS Sample site

EXPLAN

N

All concentrations in mg/L

Ca = SO4 = 

Zn = Pb = Cd = Cu = Mn = 

35.4

64.5

0.5560.0028

0.00346

0.00161.39
40 Hydrogeochemical Investigation of the Standard Mine Vicinity, Upper Elk Creek Basin, Colorado

Figure 27. Concentrations of calcium (A) and sulfate (B) in underground samples plotted versus overburden thickness.

sites with thinnest overburden (Level 3 sites 1 and 2) that 

typically had the highest (fig. 28).

Strontium Isotopes

A total of 37 samples were analyzed for strontium (Sr) 

isotopes (table 2). Measured Sr isotope ratios (87Sr/86Sr) for 

two of three replicated pairs agreed within the 2σ analytical 

error of 0.00002, and the third replicate pair agreed within 

0.00004.

Measured Sr concentrations ranged from 0.016 to 

0.650 mg/L. The distribution of concentrations at the aboveground sample sites (fig. 29) was similar to the distributions 

of specific conductance and the major ions (figs. 11, 18, and 

19); higher concentrations were found in discharge from tunnels and waste rock associated with the Standard Mine as well 

as in samples from the zone of diffuse discharge south of the 

Level 1 portal. Notably, however, Redwell spring 2 had the 

lowest Sr concentration measured in this study (0.016 mg/L). 

Samples from the Level 1 portal generally had the highest 

Sr concentrations, which reached a maximum of 0.650 mg/L 

during late winter (base flow), as did specific conductance 

(fig. 9B) and the major ions (fig. 16). Samples from Levels 

3 and 5 ranged from 0.074 to 0.398 mg/L and from 0.210 to 

0.227 mg/L, respectively. The Sr concentration of the Level 3 

samples increased with distance in from the portal.

Measured 87Sr/86Sr ratios ranged from 0.70969 to 0.71406 

(table 2). The distribution of 87Sr/86Sr ratios at aboveground 

sample sites (fig. 30) was similar to that of the metal concentrations (figs. 20–24); the highest ratios generally were found 

at tunnel and waste-rock discharge sites associated with the 

Standard and Elk Lode Mines. Strontium concentration versus 

87Sr/86Sr ratio is plotted on figure 31. Samples from areas with 

little or no mineralized rock (denoted in fig. 3 as “other”) 

generally had lower 87Sr/86Sr ratios (<0.7120), and samples 

from areas with abundant mineralized rock generally had 

higher ratios (>0.7120). The highest 87Sr/86Sr ratio (0.71406) 

was measured in the sample from the Elk Lode portal. Ratios 

in Level 1 samples were consistently among the highest 

measured and ranged from 0.71313 to 0.71365 mg/L. The 

three repeat sampling events at springs 2 and 8A displayed 

little variation in Sr isotope ratios. Underground samples from 

Levels 3 and 5 had Sr isotope ratios that ranged from 0.71279 

to 0.71344 mg/L and from 0.71149 to 0.71255 mg/L, 

respectively.

Deuterium and Oxygen-18 

Thirty-one samples were analyzed for δ2H and δ18O 

(table 3). Measured δ18O values of four replicate pairs agreed 

within the 2σ analytical error of 0.30 per mil. For δ2H, three of 

four replicate pairs agreed within the 2σ analytical error of 

4.0 per mil, and the fourth agreed within 4.2 per mil.

0

20

40

60

80

100

120

0 100 200 300 400

0

5

10

15

20

25

30

35

40

45

0 100 200 300 400

Level 3

Level 5

Ca, IN MILLIGRAMS PER LITER

OVERBURDEN THICKNESS, IN FEET

Level 3

Level 5

SO4, IN MILLIGRAMS PER LITER

OVERBURDEN THICKNESS, IN FEET

A B
Results 41

Figure 28. Concentrations of zinc (A), lead (B), cadmium (C), copper (D), and manganese (E) in underground 

samples plotted versus overburden thickness. Only samples with concentrations above detection limits are 

shown.

0

1

2

3

4

5

6

7

8

9

0 100 200 300 400

OVERBURDEN THICKNESS, IN FEET

Level 3

Level 5

Zn, IN MILLIGRAMS PER LITER

A B

C D

Level 3

Level 5

Pb, IN MILLIGRAMS PER LITER

OVERBURDEN THICKNESS, IN FEET

Level 3

Level 5

Cd, IN MILLIGRAMS PER LITER

OVERBURDEN THICKNESS, IN FEET

Level 3

Level 5

Cu, IN MILLIGRAMS PER LITER

OVERBURDEN THICKNESS, IN FEET

Level 3

Level 5

Mn, IN MILLIGRAMS PER LITER

E

OVERBURDEN THICKNESS, IN FEET

0

0.8

1.6

2.4

3.2

4.0

4.8

0 100 200 300 400

0

0.4

0.8

1.2

1.6

2.0

0 100 200 300 400 0

0.02

0.04

0.06

0.08

0.10

0.12

0 100 200 300 400

0

0.5

1.0

1.5

2.0

2.5

0 100 200 300 400
42 Hydrogeochemical Investigation of the Standard Mine Vicinity, Upper Elk Creek Basin, Colorado

Table 2. Strontium isotope content of selected water samples.

[mg/L, milligrams per liter; –R (appended to sample name), replicate sample]

Sample

name

Sr

(mg/L) 87Sr/86Sr Uncertainty(1s)

EC–S1–01 0.221 0.71328 0.00004

EC–S2–01 0.091 0.71158 0.00001

EC–S2–03 0.077 0.71159 0.00001

EC–S2–04 0.049 0.71153 0.00001

EC–S3–01 0.046 0.71110 0.00001

EC–S4–01 0.141 0.71038 0.00001

EC–S7–01 0.054 0.70969 0.00001

EC–S8A–01 0.143 0.71100 0.00001

EC–S8A–03 0.116 0.71143 0.00001

EC–S8B–01 0.143 0.71100 0.00001

EC–S9–01 0.094 0.71095 0.00004

EC–S10–01 0.118 0.71265 0.00001

EC–S11–01–R 0.038 0.71277 0.00001

EC–S12–01 0.171 0.71095 0.00001

EC–MUSTD1–01 0.148 0.71212 0.00001

EC–P4–01 0.033 0.71182 0.00001

EC–P5–01 0.058 0.71133 0.00001

EC–T1–01 0.029 0.71270 0.00001

EC–T2–01 0.088 0.71153 0.00001

EC–MSTD1–01 0.448 0.71343 0.00001

EC–MSTD1–02 0.487 0.71348 0.00001

EC–MSTD1–02–R 0.489 0.71349 0.00001

EC–MSTD1–03 0.468 0.71344 0.00001

EC–MSTD1–03–R 0.448 0.71343 0.00001

EC–MSTD1–04 0.650 0.71364 0.00001

EC–MSTD1–05 0.617 0.71365 0.00001

EC–MSTD1–06 0.407 0.71353 0.00001

EC–MSTD1–07 0.398 0.71347 0.00001

EC–MSTD1–08 0.304 0.71315 0.00001

EC–MSTD1–09 0.303 0.71315 0.00001

EC–MSTDL31–01 0.074 0.71149 0.00001

EC–MSTDL32–01 0.140 0.71209 0.00001

EC–MSTDL33–01 0.144 0.71193 0.00001

EC–MSTDL34–01 0.241 0.71241 0.00001

EC–MSTDL35–01 0.398 0.71255 0.00001

EC–M11400B–01 0.069 0.71402 0.00001

EC–M11400B–01–R 0.069 0.71406 0.00001

EC–M11600–01 0.178 0.71344 0.00001

EC–M116001–01 0.210 0.71301 0.00001

EC–M116002–01 0.227 0.71279 0.00001

Task 1

Figure 32 shows the δ18O and δ2H data for the timeseries samples. Measured values ranged from –16.61 to 

–15.14 per mil for δ18O and from –125.3 to –110.0 per mil 

for δ2H. Measured δ18O and δ2H values for all of the sites 

(except perhaps δ2H at the Level 1 portal) displayed a firstorder seasonal trend: heavier in the fall and lighter in the 

spring and early summer. The trend was most pronounced 

for Elk Creek and more muted for the three ground-water 

sites (Level 1 portal and springs 2 and 8A). Precipitation 

δ18O and δ2H values are typically heavier in rain than they 

are in snow. The first-order trend in the time-series samples 

is therefore consistent with precipitation patterns, suggesting that fall samples contained more summer and fall rain 

and that spring and early summer samples contained more 

snowmelt. This pattern would be expected at Elk Creek but 

not necessarily at the ground-water sites. Elk Creek and 

the Level 1 portal displayed a clear second-order trend (or 

first-order for δ2H at the Level 1 portal) in which both δ18O 

and δ2H values rapidly increased and then decreased during 

spring snowmelt runoff. δ18O and δ2H values might have 

spiked in the spring at springs 2 and 8A also, but the sample 

density was insufficient to resolve it.

Task 3

Measured δ18O and δ2H values for underground 

samples ranged from –17.02 to –15.65 per mil and from 

–124.3 to –114.1 per mil, respectively (figs. 33 and 34). 

These ranges are similar to those of ground-water samples 

collected aboveground during the same month (–16.63 

to –15.93 per mil for δ18O and –122.2 to –113.9 per mil 

for δ2H; table 3). Both δ18O and δ2H generally became 

lighter with increasing overburden thickness (fig. 35). 

The exception was Level 5 site 1, at which δ18O and δ2H 

values were heavier than at most other underground sites 

despite also having the greatest overburden thickness. 

Ground-surface elevations above the tunnel increase 

with overburden thickness (fig. 4), and δ18O and δ2H in 

precipitation typically decrease with elevation (Coplen and 

others, 2000). However, precipitation δ18O and δ2H values 

typically decrease with elevation at a rate of only about 

–0.05 per mil/100 ft for δ18O and about 0.4 per mil/100 ft 

for δ2H in the southern Rocky Mountains (Adams and 

others, 1995; Manning and Solomon, 2004). Given a 
Results 43

Figure 29. Strontium concentration (white type) at aboveground sample sites. Blue regions, zones of diffuse 

spring discharge; red type, Standard Mine portal. Elk Creek

Elk

Creek

Coal Creek

<0.05

0.05–0.10 >0.15

0.029

0.088

0.044

0.221

0.091

0.046

0.141

0.043

0.054

0.143

0.143

0.094

0.118

0.039

0.171

0.033 0.058

0.487

0.148

0.178

0.069

0.10–0.15

0.057

0.016

0.165

N

EXPLANATION

Sr concentration, in milligrams per liter 0

0 300 600 900 1,200 1,500 FEET

100 200 300 400 500 METERS

Redwell Basin

Elk Basin

Lower Elk Creek

Level 5 portal

Level 1 portal

Level 2 portal

Level 3 portal

Elk Lode portal
44 Hydrogeochemical Investigation of the Standard Mine Vicinity, Upper Elk Creek Basin, Colorado Elk Creek

Elk

Creek

Coal Creek

0.71270

0.71153

0.71328

0.71158

0.71110

0.71038

0.70969

0.71100

0.71100

0.71095

0.71265

0.71277

0.71095

0.71182 0.71133

0.71348

0.71212

0.71344

0.71402

<0.71100

0.71100–0.71200

0.71200–0.71300

>0.71300

Redwell Basin

Elk Basin

Lower Elk Creek

Level 5 portal

Level 1 portal

Level 2 portal

Level 3 portal

Elk Lode portal

N

EXPLANATION

0

0 300 600 900 1,200 1,500 FEET

100 200 300 400 500 METERS 87Sr 86Sr ratio

Figure 30. Strontium isotope ratios (87Sr/86Sr) (white type) at aboveground sample sites. Blue regions, 

zones of diffuse spring discharge; red type, Standard Mine portal.
Results 45

0.7090

0.7095

0.7100

0.7105

0.7110

0.7115

0.7120

0.7125

0.7130

0.7135

0.7140

0.7145

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7

87Sr/86Sr

Sr, IN MILLIGRAMS PER LITER

Adit

Level 1

Level 3

Level 5

Waste rock

Other

Figure 31. Strontium concentration at all sample sites plotted 

versus strontium isotope ratio (87Sr/86Sr).

–16.8

–16.6

–16.4

–16.2

–16.0

–15.8

–15.6

–15.4

–15.2

–15.0

7/1/06 8/31/06 10/31/06 12/31/06 3/2/07 5/2/07 7/2/07

–128

–126

–124

–122

–120

–118

–116

–114

–112

–110

–108

7/1/06 8/31/06 10/31/06 12/31/06 3/2/07 5/2/07 7/2/07

18O, PER MIL

SAMPLE DATE

Level 1 portal

Elk Creek

Spring 2

Spring 8A

2H, PER MIL

SAMPLE DATE

Level 1 portal

Elk Creek

Spring 2

Spring 8A

A

B

Figure 32. δ18O (A) and δ2H (B) concentrations at task 1 

sample sites plotted versus sample date. 
46 Hydrogeochemical Investigation of the Standard Mine Vicinity, Upper Elk Creek Basin, Colorado

Table 3. Oxygen-18, deuterium, and carbon isotope content of selected water 

samples.

[NA, not applicable; NC, not computed; NM, not measured; pmC, parts modern carbon; 

–R (appended to sample name), replicate sample]

Sample

name

Sample

date

d18O

(per mil)

d2H

(per mil)

d13C

(per mil)

14C

(pmC)

Unadjusted

14C age

(years)

EC–CELK1–01 7/18/06 –16.52 –123.2 NM NM NC

EC–CELK1–02 10/9/06 –15.14 –110.0 NM NM NC

EC–CELK1–03 2/25/07 –15.76 –116.9 NM NM NC

EC–CELK1–04 4/14/07 –16.24 –122.7 NM NM NC

EC–CELK1–05 5/5/07 –16.33 –115.9 NM NM NC

EC–CELK1–06 5/15/07 –16.34 –116.4 NM NM NC

EC–CELK1–07 6/3/07 –15.80 –115.2 NM NM NC

EC–CELK1–08 6/17/07 –15.99 –121.1 NM NM NC

EC–S2–03 10/9/06 –15.98 –119.1 NM NM NC

EC–S2–04 6/17/07 –16.18 –120.7 NM NM NC

EC–S8A–03 10/9/06 –16.36 –120.2 NM NM NC

EC–S8A–04 6/17/07 –16.61 –125.3 NM NM NC

EC–S8A–04–R 6/17/07 –16.73 –121.1 NM NM NC

EC–MUSTD1–01 8/17/06 –16.50 –122.2 NM NM NC

RW–S1–01 8/18/06 –16.63 –121.7 –8.8 98.62 58

RW–S2–01 8/18/06 –15.93 –113.9 –8.3 34.27 8550

RW–S2–01–R 8/18/06 –15.77 –115.5 –8.0 35.92 8172

EC–MSTD1–01 7/18/06 –16.34 –120.6 NM NM NC

EC–MSTD1–02 8/16/06 –16.22 –120.3 NM NM NC

EC–MSTD1–02–R 8/16/06 –16.24 –121.1 NM NM NC

EC–MSTD1–03 10/9/06 –15.83 –116.3 NM NM NC

EC–MSTD1–03–R 10/9/06 –15.87 –116.4 NM NM NC

EC–MSTD1–04 2/25/07 –16.24 –120.0 NM NM NC

EC-MSTD1-05 4/14/07 –16.12 –116.0 NM NM NC

EC-MSTD1-06 5/5/07 –16.03 –112.7 NM NM NC

EC-MSTD1-07 5/15/07 –16.19 –118.0 NM NM NC

EC-MSTD1-08 6/3/07 –16.44 –117.5 NM NM NC

EC-MSTD1-09 6/17/07 –16.19 –119.2 NM NM NC

EC-MSTDL31-01 8/17/06 –15.65 –114.1 NM NM NC

EC-MSTDL32-01 8/17/06 –16.46 –119.9 NM NM NC

EC-MSTDL33-01 8/17/06 –16.55 –121.7 NM NM NC

EC-MSDTL34-01 8/17/06 –16.82 –121.9 NM NM NC

EC-MSTDL35-01 8/17/06 –16.74 –122.9 NM NM NC

EC-M116001-01 8/17/06 –16.08 –118.8 NM NM NC

EC-M116002-01 8/17/06 –17.02 –124.3 NM NM NC
0

0 10 20

50 100 FEET

30 METERS

EXPL

N

18O = –15.65 PER MIL

18O = –16.46 PER MIL2H = –119.9 PER MIL

18O = –16.55 PER MIL2H = –121.7 PER MIL

18O = -16.82 PER MIL2H = -121.9 PER MIL

2H = –114.1 PER MIL

Figure 33. δ18O and δ2H at underground sample sites in Level 3 of Standard Mine. Adapted from Colorado Division of Reclamation, Mining, and min., mineralized or mineralization; wk. min., weakly mineralized.
00 10 20 50 100 FEET 30 METERS EXPLAN

N 18O = –17.02 PER MIL 2H = –124.3 PER MIL 

Figure 34. δ18O and δ2H at underground sample sites in Level 5 of Standard Mine. Adapted from Colorado Division of Reclamation, Mining, and Smineralized or mineralization.
Results 49

–17.2

–17.0

–16.8

–16.6

–16.4

–16.2

–16.0

–15.8

–15.6

–15.4

0 50 100 150 200 250 300 350 400

–126

–124

–122

–120

–118

–116

–114

–112

0 50 100 150 200 250 300 350 400

Level 3

Level 5

OVERBURDEN THICKNESS, IN FEET

Level 3

Level 5

OVERBURDEN THICKNESS, IN FEET

A B

18O PER MIL

2H PER MIL

Figure 35. δ18O (A) and δ2H (B) of underground samples plotted versus overburden thickness.

surface elevation increase of about 400 ft above the sampled 

sections of Levels 3 and 5, elevation effects can account for 

only about 0.2 per mil of the observed 1.4 per mil change in 

δ18O, and only about 1.6 per mil of the observed 10 per mil 

change in δ2H. The general decrease in δ18O and δ2H with 

overburden thickness must therefore primarily be caused by 

another factor, the most likely of which is increasing flowpathway length and residence time as discussed further in the 

Discussion section below.

Tritium and Noble Gases

Twenty-five samples were analyzed for 3H and 14 

samples were analyzed for dissolved gases (table 4). Up to 25 

dissolved gas samples were initially planned, but only 14 were 

collected because sampling conditions precluded the collection 

of additional reliable samples. In most cases, intended samples 

were not collected because of the obvious potential for gas 

exchange between the sampled water and the atmosphere 

upstream of the sample point. Measured 3H concentrations 

of three replicate pairs agreed within the 2σ analytical error 

(see Methods section above). Likewise, measured dissolved 

gas concentrations and the 3He/4He ratio (reported as R/Ra) 

of two replicate pairs agreed within the 2σ analytical error 

for each gas (see Methods section above). Tritium concentrations are not reported for samples collected from tributary 

2 (EC–T2–02) or from Level 3 site 2 (EC–MSTDL32–01), 

because the flasks used to store these samples for 3He 

ingrowth leaked, making 3H analysis impossible.

Task 2

Measured 3H concentrations in aboveground samples 

were all similar and ranged from 6.61 to 11.01 TU; most were 

8–10 TU (fig. 36). No clear spatial patterns were apparent 

in the 3H distribution. However, the aboveground samples 

with the four highest 3H concentrations (EC–M11600–02, 

EC–MSTD2–01, EC–M11400B–02, and RW–S2–01) were 

collected from four of the five sites where the oldest water was 

expected on the basis of either field parameters and observations (Redwell spring 2 and well 1) or the fact that the sampled 

water discharged from a mine tunnel either known or believed 

to penetrate deeply into the subsurface (Level 5 portal, Level 1 

site 2, and Elk Lode portal). 

Recharge elevations were assumed to be the approximate 

mean elevation of the portion of the watershed up-gradient 

of the sample location and have an uncertainty of ±500 ft 

or less (table 4). Variations in Hr of this magnitude result in 

variations in the apparent 3H/3He age of ±0.2 years or less 

for samples in this study. Chi-squared (χ2) misfit values were 

unacceptably high (probability <0.05) for only two sample 

(EC–S8A–02 and EC–S8B–02), which were from springs 8A 

and 8B. Measured gas concentrations for these samples did 

not fit the closed equilibrium model because lighter gases (He 

and Ne) were overly depleted and the heavier gases (Xe and 

Kr) were overly enriched. This pattern suggests that gas was 

lost from the sampled water during discharge (these samples 

were “stripped”). Such loss can occur when the sampled water 

is high in excess air and, as it emerges from the ground and the 

hydrostatic load is lost, bubbles form and gas (including 3Htrit) 

escapes. Modeled recharge parameters and apparent 3H/3He 
50 Hydrogeochemical Investigation of the Standard Mine Vicinity, Upper Elk Creek Basin, Colorado

Table 4. Dissolved gas and 3H data and 3H/3He age results.

[c2, model misfit; °C, degrees Celsius; cm3STP/g, cubic centimeters at standard temperature and pressure per gram of water; ft asl, feet above sea level; mg/L, 

milligrams per liter; yr, year; Ae and F, excess air parameters defined in text; DO, dissolved oxygen; EA, excess air, defined as the sum of the modeled excess 

air components of N2, O2, and Ar; Hr, recharge elevation; 3Hetrit, tritiogenic 3He; Heterr, terrigenic He component; NC, not computed; NM, not measured; –R 

(appended to sample name), replicate sample; R, 3He/4He ratio in sample; Ra, 3He/4He ratio in air; T, discharge temperature; Tr, recharge temperature; TU, 

tritium units].

Sample

name

T

(°C)

DO

(mg/L)

Dissolved gas concentrations

He

(cm3STP/g)

Ne

(cm3STP/g)

Ar

(cm3STP/g)

Kr

(cm3STP/g)

Xe

(cm3STP/g)

N2

(cm3STP/g)

EC–T1–02 16.0 6.36 NM NM NM NM NM NM

EC–T3–02 12.4 6.25 NM NM NM NM NM NM

EC–S2–02 6.4 8.20 3.19E-084 1.46E-07 2.96E-04 7.51E-08 1.15E-08 1.10E-02

EC–S2–02–R 6.4 8.20 3.19E-08 1.37E-07 2.90E-04 7.27E-08 1.11E-08 1.08E-02

EC–S3–02 5.4 7.92 3.20E-08 1.39E-07 3.05E-04 7.61E-08 1.14E-08 1.14E-02

EC–S4–02 3.9 9.03 3.14E-08 1.40E-07 3.12E-04 7.89E-08 1.18E-08 1.17E-02

EC–S5–02 13.8 2.54 NM NM NM NM NM NM

EC–S7–02 5.2 6.81 3.21E-08 1.45E-07 3.14E-04 7.90E-08 1.17E-08 1.18E-02

EC–S8A–02 3.4 8.56 3.10E-08 1.48E-07 3.47E-04 9.20E-08 1.48E-08 1.29E-02

EC–S8B–02 3.6 8.32 3.05E-08 1.40E-07 3.40E-04 9.16E-08 1.45E-08 1.27E-02

EC–S8B–02–R 3.6 8.32 NM NM NM NM NM NM

EC–S9–02 5.5 6.36 3.14E-08 1.41E-07 3.04E-04 7.64E-08 1.14E-08 1.14E-02

EC–S12–02 3.5 8.85 3.37E-08 1.48E-07 3.25E-04 8.25E-08 1.27E-08 1.21E-02

RW–S1–01 2.8 9.43 3.23E-08 1.46E-07 3.24E-04 8.23E-08 1.23E-08 1.21E-02

RW–S2–01 5.4 0.54 7.43E-08 3.20E-07 4.49E-04 9.88E-08 1.36E-08 2.05E-02

RW–S2–01–R 5.4 0.54 7.24E-08 3.14E-07 4.50E-04 9.89E-08 1.36E-08 2.06E-02

RW–W1–01 3.6 0.18 5.67E-08 2.37E-07 3.96E-04 9.32E-08 1.33E-08 1.68E-02

EC–MSTD2–01 4.6 8.01 3.26E-08 1.45E-07 3.18E-04 8.05E-08 1.19E-08 1.19E-02

EC–MSTDL31–01 5.1 8.20 NM NM NM NM NM NM

EC–MSTDL33–01 4.4 9.21 NM NM NM NM NM NM

EC–MSTDL34–01 4.2 8.74 NM NM NM NM NM NM

EC–MSTDL35–01 4.2 8.78 NM NM NM NM NM NM

EC–M11600–02 3.6 8.55 NM NM NM NM NM NM

EC–M116001–01 3.8 3.62 3.20E-08 1.41E-07 3.14E-04 7.90E-08 1.19E-08 1.17E-02

EC–M116002–01 3.6 NM NM NM NM NM NM

EC–M11400B–02 7.5 5.88 3.44E-08 1.44E-07 3.04E-04 7.53E-08 1.13E-08 1.16E-02

1

Assumed value, see text.

2

Chi–squared value unacceptably high.

3

He excluded in derivation of recharge parameters because stripped.

4

Read 3.19E–08 as 3.19 × 10–8.

5

Samples with negative 3Hetrit values assigned age of 0 yr.
Results 51

Table 4. Dissolved gas and 3H data and 3H/3He age results.—Continued

[c2, model misfit; °C, degrees Celsius; cm3STP/g, cubic centimeters at standard temperature and pressure per gram of water; ft asl, feet above sea level; mg/L, 

milligrams per liter; yr, year; Ae and F, excess air parameters defined in text; DO, dissolved oxygen; EA, excess air, defined as the sum of the modeled excess 

air components of N2, O2, and Ar; Hr, recharge elevation; 3Hetrit, tritiogenic 3He; Heterr, terrigenic He component; NC, not computed; NM, not measured; –R 

(appended to sample name), replicate sample; R, 3He/4He ratio in sample; Ra, 3He/4He ratio in air; T, discharge temperature; Tr, recharge temperature; TU, 

tritium units].

Modeled recharge parameters Age results

Hr

1

(ft asl)

Tr

(°C)

EA

(cm3STP/g)

Ae

(cm3STP/g) F c2 Heterr(cm3STP/g) R/Ra

3

Hetrit

(TU)

3

H

(TU)

Apparent

age5 (yr)

Initial

3

H (TU)

NC NC NC NC NC NC NC NM NC 9.04 NC NC

NC NC NC NC NC NC NC NM NC 8.48 NC NC

11,800 2.9 0.0000 0.0000 0.000 1.6 1.19E-11 0.994 0.02 8.88 0.0 8.9

11,800 3.8 0.0000 0.0000 0.000 3.1 2.66E-10 0.984 –0.01 8.80 0.0 8.8

11,900 2.2 0.0000 0.0000 0.000 1.8 1.53E-10 0.961 –0.48 9.19 0.0 9.2

11,700 1.6 0.0000 0.0000 0.000 4.0 –7.57E-10 0.974 –0.73 9.04 0.0 9.0

NC NC NC NC NC NC NC NM NC 8.97 NC NC

11,500 1.6 0.0000 0.0000 0.000 1.5 –3.56E-10 0.975 –0.49 8.33 0.0 8.3

11,500 0.0 0.0012 0.5000 0.937 19.82,3 –3.90E-09 0.958 –2.69 8.52 0.0 8.5

11,500 0.0 0.0008 0.5000 0.960 30.02,3 –3.57E-09 0.981 –2.12 8.58 0.0 8.6

NC NC NC NC NC NC NC NM NC 8.46 NC NC

11,500 2.7 0.0000 0.0000 0.000 3.4 –8.74E-10 0.975 –0.72 6.61 0.0 6.6

11,500 0.4 0.0001 0.0001 0.000 1.7 4.12E-10 0.984 0.09 8.29 0.2 8.4

11,700 0.2 0.0000 0.0000 0.000 1.3 –1.36E-10 0.982 –0.26 9.01 0.0 9.0

11,500 0.6 0.0117 0.0216 0.276 1.0 –1.75E-10 1.150 6.22 9.97 8.6 16.2

11,500 0.8 0.0118 0.0244 0.308 0.5 –2.16E-10 1.152 6.12 9.76 8.7 15.9

11,600 0.0 0.0064 0.0135 0.386 1.2 4.72E-10 1.106 3.74 8.66 6.4 12.4

11,600 1.0 0.0000 0.0000 0.000 1.2 1.31E-10 1.007 0.33 9.25 0.6 9.6

NC NC NC NC NC NC NC NM NC 8.57 NC NC

NC NC NC NC NC NC NC NM NC 7.96 NC NC

NC NC NC NC NC NC NC NM NC 9.10 NC NC

NC NC NC NC NC NC NC NM NC 9.81 NC NC

NC NC NC NC NC NC NC NM NC 11.01 NC NC

11,900 1.1 0.0000 0.0000 0.000 2.0 –8.49E-11 0.996 –0.06 11.95 0.0 11.9

NC NC NC NC NC NC NC NM NC 14.65 NC NC

11,800 2.7 0.0004 0.0004 0.000 3.7 5.15E-10 1.194 4.11 9.36 6.5 13.5
52 Hydrogeochemical Investigation of the Standard Mine Vicinity, Upper Elk Creek Basin, Colorado Elk Creek

Elk

Creek

Coal Creek

N

EXPLANATION

0 3H concentration, in Tritium units

0 300 600 900 1,200 1,500 FEET

100 200 300 400 500 METERS

<8

8–9

9–10

9.04

8.48

8.88

9.19

9.04

8.97

8.33

8.52

8.58

6.61

8.29

9.25

11.01

9.36

>10

9.01

9.97

8.66

Redwell Basin

Elk Basin

Lower Elk Creek

Level 5 portal

Level 1 portal

Level 2 portal

Level 3 portal

Elk Lode

portal

Figure 36. Tritium concentration (white type) at aboveground sample sites. Blue regions, zones of diffuse 

spring discharge; red type, Standard Mine portal.
Discussion 53

ages of such samples are not reliable. Modeled Tr values 

were 0°–4°C, consistent with a mean annual air temperature 

of about 1°C and discharge temperatures of 3°–5°C from 

the largest springs and the underground sites. Excess air 

concentrations were generally low, most ≤0.001 cm3STP/g. 

Samples from Redwell spring 2 and well 1 were clear 

exceptions; they had excess air values of 0.0117 and 

0.0064 cm3STP/g, respectively.

Apparent 3H/3He ages for the aboveground samples 

ranged from 0.0 to 8.6 yr, and all but three (from the Elk Lode 

portal, Redwell spring 2, and well 1) had apparent ages <1.0 yr 

(fig. 37). Uncertainty in the apparent age is approximately ±1 

yr for samples in this data set, given their low 4Heterr concentrations (<10–8 cm3

 STP/g), low apparent ages, low to intermediate excess air concentrations, and well-constrained Hr

 values 

(Manning and Caine, 2007). The four oldest apparent ages 

at aboveground sample sites (Redwell spring 2, well 1, Elk 

Lode portal, and Level 1 site 2) were from four of the five sites 

where the oldest water was expected, as with the 3H concentrations (see above). Apparent ages considered unreliable (from 

springs 8A and 8B and Level 1 site 2) are shown in green on 

fig. 37. The first two are unreliable because they were probably stripped (as explained above), and thus their apparent 

ages are probably erroneously young owing to loss of 3Hetrit. 

Inspection of table 4 reveals a correlation between excess air 

and age: two of the three samples have apparent ages >1 yr 

and contain considerably more excess air than samples with 

apparent ages <1 yr. This positive correlation between excess 

air and age has been observed at other mountain locations 

(Manning and Caine, 2007). The high probability that samples 

from springs 8A and 8B contained elevated excess air prior to 

discharge (causing them to become stripped) further supports 

the notion that the apparent ages of these samples are erroneously young. The sample at Level 1 site 2 was collected on 

the outby side of the collapse in the Level 1 tunnel, and it is 

unknown whether or not water inby the collapse had undergone considerable exchange with the atmosphere. If so, then 

the apparent age is again erroneously young.

Task 3

Tritium concentrations in underground samples ranged 

from 8.0 to 14.7 TU (figs. 38 and 39), higher than concentrations in aboveground samples. Tritium concentrations 

generally increased with overburden thickness (fig. 40), suggesting a positive correlation between 3

H concentration and 

flow-pathway length and thus residence time. However, the 3H 

concentration at Level 5 site 1 was lower than at Level 5 site 2, 

counter to the overall trend.

Only one dissolved gas sample was collected in Levels 

3 and 5; it came from Level 5 site 1 on the outby side of the 

collapse near the end of Level 5. As at Level 1 site 2, it is 

unknown whether water inby the collapse had undergone gas 

exchange with the atmosphere. Its apparent age of 0.0 yr is 

therefore considered unreliable. If gas exchange did occur, the 

apparent age is erroneously young.

Carbon-14

Two samples were analyzed for 13C and 14C in dissolved 

inorganic carbon (table 3). For the one replicate pair, δ13C 

agreed within the reported 2σ analytical error of 0.3 per mil. 

The 14C activity of the replicate pair differed by 1.6 percent 

modern carbon, more than the typical 2σ analytical error of 

1.0 percent modern carbon. This larger-than-expected discrepancy is probably a result of the very low dissolved inorganic 

carbon concentration in the replicated sample (pH = 3.68). 

 The sample from Redwell spring 1 (RW–S1–01) was 

collected to characterize the carbon isotope signature of young 

ground water at the site, information that is necessary in 

interpreting the 14C age of older ground water. As expected, 

the 14C activity was high (98.62 percent modern carbon), 

indicating an unadjusted age of 58 yr. Note that under the 

best circumstances, 14C ages seldom have uncertainties less 

than ±1,000 yr. A sample was collected from Redwell spring 

2 because it was suspected, on the basis of field parameters 

and observations, that water discharging from this spring was 

the oldest near the Standard Mine. The sample from Redwell 

spring 2 (RW–S2–01) had a 14C activity of 34.27 percent modern carbon, indicating an unadjusted age of 8,550 yr. However, 

the unadjusted age does not take into account possible changes 

in the 14C activity of dissolved inorganic carbon resulting 

from chemical reactions with dissolved inorganic carbon in 

the unsaturated and saturated zone or from mixing with other 

fluids. The chemical mass balance would have to be modeled in detail to quantify the influence of these processes and 

compute an adjusted age. Age adjustments typically reduce the 

unadjusted age 0 to 10,000 yr. Tritium and 3He data indicated 

that water from Redwell spring 2 was about 9 yr old, and 

computed initial 3H concentrations confirmed that it contained 

little water recharged prior to the early 1950s (see Discussion 

section below). These data confirm that processes other than 

radioactive decay almost certainly have markedly reduced the 

14C activity of water discharging from Redwell spring 2 and 

that the unadjusted age has essentially no meaning. Given the 

low pH of water from Redwell spring 2, the large unadjusted 

age is most likely due to the dissolution of calcite along flow 

pathways; calcite has a low 14C activity. The δ13C value for the 

sample (–8.0 per mil) was greater than that at Redwell spring 1 

(–8.8 per mil), consistent with some dissolution of calcite, 

which typically has δ13C values of 0 to –6 per mil. 

Discussion

Distribution of Ground-Water Discharge and 

Potential Geologic Controls on Flow 

The only clear trend in the spatial distribution of groundwater discharge (aboveground) is that discharge was not 

observed on the ridges rimming Elk Basin but only at the 
54 Hydrogeochemical Investigation of the Standard Mine Vicinity, Upper Elk Creek Basin, Colorado Elk Creek

Elk

Creek

Coal Creek

<1

>1

0.0

0.0

0.0

0.0

0.0

0.0

0.0

0.2

0.6

6.5

0.0

8.6

6.4

Elk Lode portal

Redwell Basin

Elk Basin

Lower Elk Creek

Level 5 portal

Level 1 portal

Level 2 portal

Level 3 portal

N

EXPLANATION

Apparent 3H/3He age, in years 0

0 300 600 900 1,200 1,500 FEET

100 200 300 400 500 METERS

Figure 37. Apparent 3H/3He age (white and green type) at aboveground sample sites. Values in green 

considered unreliable (see text). Blue regions, zones of diffuse spring discharge; red type, Standard Mine 

portal.
0

0 10 20

50 100 FEET

30 METERS

EXP

N

3H = 8.57 Tritium units

3H = NM

3H = 7.96 Tritium units

3H = 9.10 Tritium units

Figure 38. Tritium concentration at underground sample sites in Level 3 of the Standard Mine. Adapted from Colorado Division of Reclamation, and Safety (2007). NM, not measured; min., mineralized or mineralization; wk. min., weakly mineralized.
00 10 20 50 100 FEET 30 METERS EXPLAN

N 3H = 14.65 Tritium units Age = NM 

Figure 39. Tritium concentration and apparent 3H/3He age at underground sample sites in Level 5 of the Standard Mine. Apparent age at site 1 (funreliable for reasons explained in text. Adapted from Colorado Division of Reclamation, Mining, and Safety (2007). NM, not measured; min., minemineralization.
Discussion 57

6

7

8

9

10

11

12

13

14

15

16

0 50 100 150 200 250 300 350 400

Level 3

Level 5

OVERBURDEN THICKNESS, IN FEET

3H, IN TRITIUM UNITS

Figure 40. Tritium concentration in underground samples plotted 

versus overburden thickness.

foot of the headwall or on the basin floor (fig. 5). The water 

observed in the exploration pits is probably shallow ground 

water, and the elevation of the surface of that water probably reflects the water-table elevation. However, the shallow 

ground-water system may be perched, in which case water levels in the pits would be unrelated to water levels in the deeper, 

watershed-scale to regional-scale ground-water system.

Shallow water levels (<8 ft) in basin-floor pits and extensive 

ground-water discharge on the basin floor both suggest that the 

water table is generally near the ground surface on the basin 

floor. Dry exploration pits and an absence of any ground-water 

discharge above the basin floor suggest that the water table 

is deeper under the ridges rimming the basin. This relation is 

expected, given that water tables are typically muted expressions of the topography, hence deeper under ridges.

More sample sites are located in the Ohio Creek 

Formation than in the Wasatch Formation (fig. 8). However, 

this difference in number is probably due to the location of 

these units in the basin rather than to systematic permeability 

contrasts between them; the Ohio Creek Formation underlies 

most of the basin floor (where ground water discharges), 

whereas the Wasatch Formation underlies most of the ridges 

rimming the basin (where ground-water does not discharge). 

Ground water does discharge where the Wasatch Formation 

underlies the basin floor at springs 9, 8A, 8B, and 12. No clear 

correlation exists between natural ground-water discharge 

locations and map-scale faults; several springs lie in the 

general vicinity of a fault, but few are located directly on 

a fault as would be expected if ground water flowed to the 

discharge location primarily through the fault. The greater 

density of sample sites along the Standard fault is due to the 

mine workings there, not to more sites of natural groundwater discharge. The lack of correlation between spring 

discharge and the map-scale faults suggests that these 

structures exert little influence on shallow ground-water flow, 

although they may strongly influence deeper ground-water 

flow. The degree to which outcrop-scale geologic structures 

control ground-water flow cannot be assessed on the basis of 

surface observations, because the springs generally discharge 

in float. In short, surface observations suggest that simple 

topography, rather than large-scale geologic features (mapscale faults and lithology), primarily controls the occurrence 

and flow of shallow ground-water in Elk Basin.

Because the primary source of water flowing into the 

Standard Mine appeared to be gouge and breccia in the Standard fault, the Standard fault itself is probably the main pathway of ground-water flow from the shallow subsurface to 

the mine workings. The fact that material in cross faults was 

saturated and dripping suggests that these cross faults may 

also contribute some flow to the mine. However, the lack 

of increased inflow rates where these cross-faults intersect 

Level 5 suggests that such contributions are relatively minor. 

Inflows throughout Levels 3 and 5 present the possibility that 

ground-water commonly circulates to depths of at least 500 

feet throughout Elk Basin. However, the fact that the fault 

material was the primary source of inflowing water suggests that most of the ground-water flow at these depths, if it 

does occur elsewhere in the basin, is likely localized within 

map-scale fault zones such as the Standard fault. The mine 

workings might allow ground water to circulate far deeper 

in the Standard fault than it would naturally, by providing a 

drain and drawing water down to the tunnel elevations. The 

installation of monitoring wells would be required to further 

characterize deeper ground-water flow in Elk Basin and the 

manner in which ground-water flows to the Standard Mine 

workings.

Ground-Water Residence Times

The 3H and 3He data along with measured δ18O and 

δ2H values provide important information on ground-water 

residence times within the Standard Mine and surrounding 

area. Water recharged prior to the early 1950s (prebomb 

water) would have had a 3H concentration <0.5 TU in the 

year 2006. Because measured 3H concentrations were 

≥6.61 TU, all samples were composed partly or completely 

of water recharged after the early 1950s (postbomb 

water). Mean annual precipitation 3H concentrations were 

computed from monthly and quarterly precipitation 3H data 

for the period 1970 to 2006 at Salt Lake City, Utah, and 

Albuquerque, N. Mex., the two cities closest to the site with 

extended precipitation 3H records (fig. 41). Both records 

are shown because it is uncertain which record is more 

representative of precipitation at the site. Concentrations for 
58 Hydrogeochemical Investigation of the Standard Mine Vicinity, Upper Elk Creek Basin, Colorado

years with no data were estimated on the basis of correlations 

with complete records from other cities as described by 

Manning and others (2005). Precipitation 3H concentrations 

decayed to 2006 levels are also shown in fig. 41. Tritium 

concentrations for samples in this study were similar to 

expected current concentrations in precipitation recharged 

within the past 35 yr (5–15 TU), suggesting that, if the 

sampled waters were unmixed, they were <35 yr old. Apparent 

3

H/3He ages further constrain ground-water residence times: if 

sampled waters again were unmixed, they were <9 years old 

and most were <1 yr old.

However, actual ground-water ages can be considerably 

older than apparent 3H/3He ages for samples that are mixtures 

of postbomb and prebomb water, and such mixing cannot be 

ruled out on the basis of 3H concentration or apparent 3H/3He 

age alone. Potential mixing can be evaluated by comparing 

computed initial 3H concentrations (measured 3H + measured 3

Hetrit; table 4) with precipitation 3H concentrations at 

the apparent time of recharge (fig. 42). Tritium concentrations in precipitation vary seasonally, but initial 3

H values 

are commonly compared with mean annual concentrations in 

precipitation (fig. 42) because dispersion along ground-water 

flow pathways is expected to erase seasonal signals in water 

>1 yr old. The three samples with apparent ages >1 yr all plot 

close to the Salt Lake City record (fig. 42), suggesting that 

this record represents precipitation at the site better than the 

Albuquerque record. Initial 3H values from Handcart Gulch in 

Park County in the Front Range, the only other alpine site in 

Colorado where extensive 3H/3He ground-water age data have 

been collected, are also more consistent with the Salt Lake 

City record than the Albuquerque record (Manning and Caine, 

2007). The fact that these three samples do not plot below 

either record suggests that they contained little or no prebomb 

water and that the apparent age closely approximates the true 

mean age.

Samples with apparent ages <1 yr mostly plot below the 

Salt Lake City record and closer to the Albuquerque record. 

There are three possible explanations: these samples contained 

some prebomb water; the Albuquerque record better represents precipitation at the site; or these samples were affected 

by seasonal variations in precipitation 3H concentrations. The 

first explanation is unlikely. It is difficult to imagine a groundwater flow configuration for the site area that would consistently produce large fractions of prebomb water in samples 

with the youngest apparent ages but no prebomb water in 

samples with older apparent ages. Further, we are not aware of 

any published ground-water age data sets that show evidence 

of such a mixing pattern. The second explanation is also 

unlikely, given how well the three samples with apparent ages 

>1 yr match the Salt Lake City record. The third explanation 

is the most likely. Quarterly precipitation 3H concentrations 

for Albuquerque, N. Mex., from 1997 to 2002 (the final five 

years that data were collected at this station) show a seasonal 

cycle in which concentrations are higher in winter and spring 

and lower in summer and fall (fig. 43). This pattern is common 

throughout North America. If the samples with apparent ages 

0

5

10

15

20

25

30

35

40

45

50

1970 1974 1978 1982 1986 1990 1994 1998 2002 2006

SLC

ALB

SLC decayed

ALB decayed

3H, IN TRITIUM UNITS

YEAR

Figure 41. Precipitation 3H records for Salt Lake City, Utah 

(SLC), and Albuquerque, N. Mex. (ALB). Precipitation tritium 

concentrations decayed to 2006 levels (SLC decayed and ALB 

decayed) are also shown.

<1 yr contained a large component of water only weeks to 

months old, then they contained a large component of summer 

precipitation having 3H concentrations below the annual mean, 

thus explaining their low initial 3H concentrations. The 3H and 

He data therefore suggest that much of the ground water in the 

Standard Mine vicinity is extremely young and has residence 

times of weeks or months rather than years.

The spatial distribution of 3H concentration is consistent with much of the water at the site being <1 yr old. The 

aboveground samples with the four highest 3H concentrations 

are from four of the five locations where the oldest water was 

expected on the basis of either field parameters and observations or the fact that the sampled water discharged from a mine 

tunnel (fig. 36). More important, 3H concentrations in underground samples generally increased with overburden thickness 

(fig. 40). Both of these trends suggest that older samples 

generally have higher 3H concentrations than younger samples. 

All 3H samples were collected in late summer. A positive 

correlation between 3H concentration and age is therefore 

consistent with much of the water at the site being months 

old. Younger samples containing mostly water <2 months old 

would contain a larger fraction of summer rain and thus have 

lower 3H concentrations (fig. 43). Older samples containing 

mostly water >2 months old would contain a larger fraction 

of spring snowmelt and thus have higher 3H concentrations. 
Discussion 59

2

4

6

8

10

12

14

16

18

20

1992 1994 1996 1998 2000 2002 2004 2006

SLC

ALB

Sample

APPARENT RECHARGE YEAR

INITIAL 3H, IN TRITIUM UNITS

Figure 42. Initial 3H concentration (measured 3H + 

measured 3Hetrit) in samples plotted versus apparent 

recharge year (determined from apparent 3H/3He age). 

Precipitation 3H records for Salt Lake City, Utah (SLC), and 

Albuquerque, N. Mex. (ALB) are also shown.

2

4

6

8

10

12

14

16

18

1997 1998 1999 2000 2001 2002

YEAR

3H CONCENTRATION, IN TRITIUM UNITS 

Figure 43. Quarterly 3H concentration in precipitation at 

Albuquerque, N. Mex., 1997–2002.

If instead the youngest water at the site were about 1 yr old 

(recall that the uncertainty in the apparent 3H/3He age is 

±1 yr), then older samples would have 3H concentrations 

similar to or lower than the younger samples (fig. 41)—if the 

oldest water at the site were <10 yr old (as suggested by the 

maximum apparent age of 9 yr at Redwell spring 2).

Another important feature of the underground 3H 

distribution is that the concentration decreased from 

14.65 TU at Level 5 site 2 in the middle of the tunnel to 

11.95 TU at Level 5 site 1 near the end of the tunnel, which 

is the reverse of the general trend of 3H concentration 

increasing with overburden thickness (and age). It is 

possible that water at site 1 was younger than water at site 2. 

However, no shafts connect Level 5 to higher tunnels or to 

the surface (fig. 4), and thus no obvious fast-flow pathways 

preferentially connect site 1 to the surface. Furthermore, 

specific conductance is higher at site 1 than at site 2, and 

specific conductance is apparently positively correlated with 

age in waters with circumneutral pH (fig. 14B). Therefore, 

a more likely explanation is that water at site 1 was indeed 

older than water at site 2, but its 3H concentration was lower 

because its age was ≥1 yr. Assuming that the Salt Lake City 

precipitation 3H record is representative of the site, ground 

water with an age of 1–10 yr should have a 3H concentration 

of 8–12 TU (fig. 41). The sample at site 2 had a 3H 

concentration above this range (14.65 TU), suggesting that 

it contained a substantial fraction of snowmelt water (water 

2–4 months old). The sample at site 1 had a 3H concentration 

within this range (11.95 TU), consistent with being 1–10 yr 

old.

The δ18O and δ2H data are also consistent with much of 

the water at the site being <1 yr old. Seasonal variations in 

δ18O and δ2H were more muted at the Level 1 portal than at 

Elk Creek (fig. 32). This lesser variation is expected given 

that ground water is generally older than creek water, much 

of which resides only hours to days (if at all) in the groundwater system. However, the fact that δ18O and δ2

H values did 

vary seasonally at the Level 1 portal means that the portal 

discharge must have contained an appreciable fraction of 

water <1 yr old. If all portal discharge were >1 yr old, such 

seasonal isotopic variations (particularly of those isotopes 

that closely track seasonal variations in precipitation) would 

be unlikely given natural dispersion in the ground-water 

system, and δ18O and δ2H values would remain relatively 

constant throughout the year. δ18O and δ2H data from the 

Level 1 portal therefore also suggest that a large mine pool 

extending above the elevation of Level 1 does not exist in the 

Standard Mine. If such a large reservoir of water did exist, 

most ground water entering into the mine presumably would 

reside within the mine for well over one year. The substantial seasonal variations in δ18O and δ2

H suggest that such is 

not the case. Furthermore, the apparent 3H/3He age for the 

sample collected just inside the portal at Level 1 site 2 was 

0.6 yr. This apparent age could be erroneously young owing 

to unseen gas exchange inby the collapse where the sample 

was collected. However, such gas exchange would require 
60 Hydrogeochemical Investigation of the Standard Mine Vicinity, Upper Elk Creek Basin, Colorado

that the mine tunnel be filled largely with air inby this collapse, a requirement that is inconsistent with the mine being 

flooded inby the collapse (in other words, with a large mine 

pool extending above Level 1).

Measured δ18O and δ2H values for underground samples 

generally decreased with overburden thickness (fig. 35), and 

elevation changes at the ground surface above can account 

for only a small fraction of this decrease (see Results section 

above). This correlation with overburden thickness is consistent with samples from shallower tunnel sites that contain 

larger fractions of summer rain (water <2 months old) and 

samples from deeper tunnel sites that contain larger fractions of snowmelt water (water 2–4 months old). Again, if all 

ground water entering Levels 3 and 5 were >1 yr old, δ18O 

and δ2H values should vary little throughout the tunnels owing 

to natural dispersion. As with 3H, the general trend reversed 

between Level 5 site 2 and Level 5 site 1 (fig. 35); δ18O and 

δ2H were heavier rather than lighter with greater overburden 

thickness. Samples from Redwell spring 2 and the Level 1 

portal at base flow (EC–MSTD1–04, collected in February) 

provide the best estimation of the δ18O of water that is 1–10 yr 

old, because the former had an apparent 3H/3He age in this 

range (the only such sample for which δ18O was measured) 

and the latter was presumably the oldest of the other samples 

for which δ18O was measured. δ18O values for these two 

samples (table 3) suggest that water 1–10 yr old had a δ18O 

of approximately –15.9 to –16.2 per mil. Water at Level 5 

site 2 had a δ18O well below this range (–17.02 per mil) and 

likely contained a large fraction of snowmelt water (water 

2–4 months old). Water at site 1 had a δ18O of –16.08 per mil, 

consistent with water 1–10 yr old.

Controls on Ground-Water Chemistry

Controls on Metal Concentrations

The presence of sulfide-rich mineralized rock is the 

primary control on dissolved metal concentrations and pH in 

ground water in the Standard Mine vicinity. Ground-water pH 

was consistently low and Zn, Pb, Cd, Cu, and Mn concentrations were consistently elevated at aboveground sample sites 

located within or immediately downgradient of areas where 

sulfides are abundant (figs. 10, 20–24), namely the Standard 

fault, the Elk Lode portal, and the breccia pipe in Redwell 

Basin. Metal concentrations in underground samples in the 

Standard Mine, which follows mineralized rock in the Standard fault, were also generally higher than in aboveground 

samples located outside of the sulfide-rich areas (figs. 28, 

20–24). Metal concentrations in discharge from the Level 1 

portal were among the highest measured in Elk Basin, and the 

time-series data indicate that they remained so throughout the 

year (fig. 17). The pH at underground sites and at the Level 1 

portal was as low as 3.3 (fig. 9A and 14A), whereas samples 

from locations outside sulfide-rich areas were consistently 

circumneutral.

Whether or not sulfide-rich rock occurs in waste-rock 

piles appears to be another major control on ground-water 

metal concentrations and pH. Spring 1 and the Level 2 waste 

rock site had the lowest pH and, typically, the highest metal 

concentrations, and both are sites where the sampled water 

discharged directly from waste rock. The waste-rock piles at 

these sites are associated with the Standard Mine workings 

(fig. 5). The interior of the piles could not be observed, and 

it is possible that they contain rock that is more sulfide rich 

than at other sites. However, the fact that the waste rock came 

from the Standard Mine means that its sulfide content should 

be similar to that of mineralized rock still in place within the 

mine. More likely, waste-rock piles allow greater water-rock 

interaction than sulfide-bearing rocks still in place because 

the piles are a porous medium rather than a fractured-rock 

medium; thus, the total surface area per unit volume of rock 

where water can directly contact and react with minerals is 

far greater. Furthermore, the exposed mineral surfaces may be 

fresher (tens of years old), and thus more reactive, than those 

along well established flow pathways in the native ground (at 

least thousands of years old). It is also possible that more oxygen is available for sulfide oxidation because saturated portions of the waste-rock piles may be thin and highly transient, 

allowing considerable oxygen exchange between ground-water 

and air. Regardless of the actual controlling mechanism, 

waste-rock piles appear to be the source of some of the lowestpH and most metal-rich ground water near the Standard Mine.

Controls on Major Ion Chemistry

As with metal concentrations, major ion concentrations 

are controlled in part by the presence of sulfide-rich rock, 

and whether or not this rock is in waste-rock piles. Ca and 

SO4 concentrations and specific conductance were commonly 

elevated where pH was low and metal concentrations were 

high (figs. 11, 18, and 19). Further, samples from spring 1 

(waste rock discharge) and the Level 2 waste rock site, which 

had the lowest pH values and typically the highest metal concentrations, also had the highest specific conductance values 

(fig. 11). Major ion concentrations were probably high in areas 

with abundant sulfides because the low pH caused by sulfide 

dissolution increased the dissolution of other minerals.

However, major ion concentrations are apparently 

controlled by another factor as well: residence time. Specific 

conductance and Ca and SO4 concentrations in the underground samples all generally increased with overburden 

thickness (figs. 14B and 27), which is presumably correlated 

with flow-pathway length and thus residence time. Major ion 

concentrations probably increase with increasing residence 

time owing to progressive dissolution of more easily dissolved 

minerals such as calcite and gypsum along ground-water 

flow pathways within the sedimentary rocks underlying most 

of the site, which have undergone only low-grade alteration. 

Note that, although the Standard fault zone contains abundant 

sulfides, the circumneutral pH of most of the underground 

samples suggests that the grade of alteration in the fault zone 
Discussion 61

(or in much of the fault zone) was not high enough to remove 

all the carbonate. Residence time had little apparent influence 

on the pH and metal concentrations. Metal concentrations 

did not systematically increase and pH did not systematically decrease with overburden thickness in the underground 

samples (figs. 14A and 28). Further, metal concentrations 

were high and pH was low in older aboveground samples (for 

example, at Redwell spring 2) and in presumably very young 

aboveground samples (for example, pit 5).

Specific conductance, Ca, and SO4 were all somewhat 

elevated in the area of diffuse spring discharge south of the 

Level 1 portal where springs 8A, 8B, and 12 are located 

(figs. 11, 18, and 19). Older ground water in this area could 

produce higher specific conductance. This speculation is 

consistent with the probable high excess air levels at springs 

8A and 8B (see Results section above), but inconsistent with 

the apparent age at spring 12 of only 0.2 yr (fig. 37). It could 

also be the result of mineralogical differences between the 

Wasatch Formation, which underlies this area south of the 

Level 1 portal, and the Ohio Creek Formation, which underlies the rest of the sampled portion of Elk Basin (spring 9 

excepted; fig. 8). The cause of elevated major ion concentrations in this part of the study site remains unclear.

Controls on Standard Mine Water Chemistry

The likely sources of Zn, Pb, Cd, and Cu in ground 

water in and near the Standard Mine are sphalerite (ZnS), 

galena (PbS), and chalcopyrite (CuFeS2), which are commonly observed in mineralized zones in the Standard fault 

and in waste-rock piles associated with the Standard Mine. 

Sphalerite is the likely source of Cd and Zn. Cadmium can 

substitute for Zn in the sphalerite crystal lattice because its 

atomic size is similar to that of Zn, so sphalerite regularly 

contains small percentages of Cd. The Zn/Cd ratio was relatively constant in the sampled waters (fig. 44). Ratios were 

generally in the range of 100–300, similar to ratios measured 

by Plumlee and others (2005) in sphalerite in the Questa 

porphyry molybdenum deposit in northern New Mexico, 

further supporting sphalerite as the source of Cd. Manganese 

enrichment is common in porphyry-type molybdenum deposits such as that underlying Mt. Emmons. Siderite (FeCO3

) is 

commonly associated with such deposits and is a potential 

source of Mn because Mn commonly substitutes for Fe. 

Siderite is therefore a possible source of Mn in ground water 

near the Standard Mine, although the presence of siderite in 

and near the Standard fault was not confirmed.

The location within the flow system where these 

metals become dissolved in the ground water (the source 

location) remains unknown. To evaluate possible mixing 

among different sampled waters, zinc was plotted against 

SO4 (fig. 45). Zinc and SO4 were chosen because they were 

among the most abundant constituents in the sampled waters 

and because, when waters of differing pH are mixed, neither 

will precipitate unless the pH rises above about 8. Level 1 

portal discharge had the highest concentrations of Zn and 

0

0.05

0.10

0.15

0.20

0.25

0 5 10 15 20 25 30

Cd, IN MILLIGRAMS PER LITER

Zn, IN MILLIGRAMS PER LITER

Redwell spring 2

Level 1

Level 3

Level 5

Elk Creek

Waste rock

Other

Figure 44. Zinc concentration at all sample sites plotted versus 

cadmium concentration.

SO4 of all waters sampled except the waste-rock waters from 

spring 1 and the Level 2 waste rock site (fig. 45). Thus, none 

of the sampled waters, other than those from spring 1 and the 

Level 2 waste rock site, could have been the primary source 

of metals in Level 1 discharge. It is emphasized that sulfides 

in the immediate vicinity of Levels 3 and 5 were not the 

primary source of metals in Level 1 discharge. Although it is 

chemically possible that the sampled waste-rock waters were 

the source, it is highly unlikely because the volume of water 

observed discharging from the waste rock (and thus, presumably, flowing through the waste rock) was small in comparison 

to the volume of water discharging from Level 1. In addition to Zn and SO4

, concentrations of other constituents (for 

example, Cd and Ca), were greater in Level 1 discharge than 

in waters from Levels 3 and 5 (appendix 3). Measured 87Sr/86Sr 

ratios were also higher in Level 1 discharge than in samples 

from Levels 3 and 5 (fig. 31). Therefore, in short, the primary 

source location of metals in Level 1 discharge was not found 

in this study.

Two types of sources are possible for metals in Level 

1 discharge. The first is an unseen mineralized zone that is 

substantially richer in ore minerals than any encountered in 

the observable portions of the Standard fault. Unsampled 

water draining this zone could be more metal-rich than water 

sampled in Levels 3 and 5 and could mix with water similar to 

that sampled in Levels 3 and 5 to form Level 1 discharge. Such 

a zone would need to be located below Level 3 or farther back 

into the mountain than the ends of the Levels 3 and 5 tunnels. 

The fact that Level 1 extends an unknown distance under the 
62 Hydrogeochemical Investigation of the Standard Mine Vicinity, Upper Elk Creek Basin, Colorado

ridge between Elk and Redwell Basins presents the possibility 

that mineralization associated with the breccia pipe in Redwell 

Basin could be the source. However, this mineralized area is 

the source of metals at Redwell spring 2, and concentrations of 

Zn and SO4 at Redwell spring 2 are clearly too low to suggest 

that this same area is the source of metals in Level 1 discharge 

(fig. 45).

The second possible type of source zone contains rock 

with the same degree of mineralization as that observed but 

under conditions more favorable for the dissolution of metals. 

Waters similar to those observed in Levels 3 and 5 could flow 

through such a zone and acquire higher metal concentrations 

to become similar to Level 1 discharge. Given the high metal 

concentrations observed in the waste-rock waters, a reasonable 

possibility is that the mineralized rock in a source zone of this 

type would form a porous medium, such as an extensive pile 

of rubble or debris within the mine workings below Level 3. 

As explained above, several factors might allow rock in such 

a porous medium to produce metal concentrations higher than 

those observed in Levels 3 and 5. Determining which type of 

source is responsible for the metals in Level 1 discharge is not 

possible without further investigation.

Controls on Elk Creek Water Chemistry

The patterns of seasonal variations in field parameters, 

chemical constituents, and stable isotopes were very similar 

in Level 1 discharge and in Elk Creek (figs. 9, 16, 17, and 

32), suggesting that Level 1 discharge may be the primary 

source of metals in Elk Creek. At the time of preparation of 

this report, flow data from September 2006 were the only 

flow data available for the Level 1 portal and for Elk Creek 

(Christina Progess, U.S. Environmental Protection Agency, 

oral communication, September 2007). A flow rate of 0.021 

cubic feet per second (cfs) was measured on September 13, 

2006, at the Level 1 portal site, and a flow rate of 1.29 cfs 

was measured on September 12, 2006, approximately 200 ft 

downstream from the Elk Creek sample site (no tributaries 

enter the creek between the sample site and the flow measurement location). These flow rates were used in combination 

with metal concentrations measured in the summer of 2006 

(figs. 20–24) to calculate mass fluxes for Zn, Pb, Cd, Cu, and 

Mn at the Level 1 portal and at the Elk Creek sample site for 

the times when flow data were collected. Calculated mass 

fluxes are only estimates because the metal concentrations 

used were collected several weeks before the flow measurements. Estimated mass fluxes for the Level 1 portal are Zn, 

14 milligrams per second (mg/s); Pb, 0.39 mg/s; Cd, 

0.090 mg/s; Cu, 0.13 mg/s; and Mn, 6.0 mg/s. Estimated 

mass fluxes for the Elk Creek sample site are Zn, 16 mg/s; 

Pb, 0.015 mg/s; Cd, 0.080 mg/s; Cu, 0.073 mg/s; and Mn, 

0.47 mg/s. Mass fluxes at the Elk Creek sample site are 

approximately the same as (Zn and Cd) or lower than (Pb, Cu, 

and Mn) those at the Level 1 portal, consistent with Level 1 

discharge being the primary source of metals in Elk Creek. 

A prominent feature of the time-series data is that pH 

dropped and metals concentrations rose during the early stages 

of spring runoff (figs. 9 and 17) in Elk Creek and in Level 1 

discharge. Rapid infiltration of snowmelt water in the spring 

therefore must have mobilized a low-pH, metal-rich component of ground water in and near the Standard Mine. δ18O and 

δ2H values became heavier during spring runoff at both sample 

sites (fig. 32) before dropping back down to lighter values representative of spring snowmelt. The stable isotope data suggest 

that the seasonal low-pH, metal-rich component (spring flush 

water) contained a large fraction of summer and fall rainwater. 

One hypothesis is that the spring flush water originated from 

a location where ground-water flow ceased as water levels 

fell over the winter, such that water recharged mainly in the 

late summer or fall became immobile. Reasonable candidate 

locations include pockets of high capillarity material (finegrained fault gouge or intensely microfractured rock) within 

the seasonally saturated zone (unsaturated in the winter, saturated in spring) near the ground surface or within parts of the 

mine workings that become saturated only during spring high 

flow. Immobilized water in these pockets could have acquired 

particularly low pH values and high metal concentrations 

during the winter given the lack of flow, high mineral surface 

contact area, and high oxygen availability (the pockets would 

be surrounded by air). One complication for this hypothesis is 

that increases in concentrations of Zn, Cd, and Mn in Level 1 

discharge were minor to nonexistent during the early stages of 

spring runoff, suggesting that the spring flush water was high 

0

5

10

15

20

25

30

0 50 100 150 200 250 300 350

Redwell spring 2

Level 1

Level 3

Level 5

Elk Creek

Waste rock

Other

Zn, IN MILLIGRAMS PER LITER

SO4, IN MILLIGRAMS PER LITER

Figure 45. Sulfate concentration at all sample sites plotted 

versus zinc concentration.
Conclusions 63

in Pb and Cu, but not in Zn, Cd, and Mn. A reason for this 

discrepancy in the metal concentrations is not clear.

Although increases in Zn, Cd, and Mn concentrations 

during spring runoff were minor to nonexistent in Level 1 

discharge, concentrations of these three metals increased 

sharply in Elk Creek. One possible explanation is that the 

Level 1 portal water (assuming it is the source of these metals 

in Elk Creek) simply composed a larger fraction of Elk Creek 

water during spring runoff. However, this possibility seems 

unlikely given the presumed increase in overland flow to the 

creek owing to rapid snowmelt in the spring. Another possible 

explanation is that the slight drop in pH of Elk Creek water 

during spring runoff was sufficient to dissolve Zn, Cd, and 

Mn sorbed to suspended sediment particles under higher pH 

conditions. This effect would not have been observed at the 

Level 1 portal because portal discharge is essentially free of 

suspended sediment all year. A third possible explanation is 

that the increase in suspended sediment in Elk Creek during 

spring runoff resulted in an increase in colloids smaller than 

0.45 μm, sufficiently small to pass through the sample filters 

used in this study (Kimball and others, 1995). Zinc, Cd, and 

Mn sorbed to such colloids could have caused an apparent 

increase in the dissolved concentrations of these metals in Elk 

Creek samples but not in portal discharge samples, which were 

free of suspended sediment. Further study would be required 

to better understand the potentially complex processes controlling metal concentrations in Elk Creek.

Conclusions

1. No clear correlation was observed between natural 

ground-water discharge locations and map-scale faults 

and lithology. Surface observations and the location of 

ground-water discharge suggest that simple topography, 

rather than large-scale geologic features, primarily controls the occurrence and flow of shallow ground water in 

Elk Basin.

2. Discrete inflows from cross faults or other features were 

not observed in Levels 3 and 5 of the Standard Mine. 

Instead, water entered the mine as persistent dripping 

from gouge and breccia within the Standard fault, which 

both tunnels follow. Therefore, the Standard fault itself is 

probably the main pathway of ground-water flow from the 

shallow subsurface to the mine workings.

3. Apparent tritium/helium-3 ground-water ages ranged from 

0 to 9 yr, and the considerable majority were <1 yr. The 

tritium data and computed initial tritium values (measured 

tritium plus measured tritiogenic helium-3) suggest that 

much of the ground water in the Standard Mine vicinity 

was weeks to months old rather than years old.

4. Tritium, δ18O, and δ2H data from ground water entering 

into and discharge from the Standard Mine all displayed 

spatial and temporal patterns indicating that they were 

influenced by seasonal variations in their concentration 

in precipitation. These data therefore suggest that ground 

water entering into and discharging from the Standard 

Mine was largely composed of water <1 yr old. Short residence times for much of the water in the Standard Mine 

are consistent with the pronounced seasonal variations in 

geochemistry observed in Level 1 discharge. The short 

residence times are not consistent with a large mine pool 

that extends above the Level 1 tunnel.

5. The pH was consistently low and metal concentrations 

were consistently elevated in aboveground samples 

located within or immediately down-gradient of areas 

where sulfides are abundant, including the Standard fault, 

the Elk Lode portal, and the breccia pipe in Redwell 

Basin. Metal concentrations in underground samples from 

the Standard Mine, which follows mineralized rock in the 

Standard fault, were also generally higher than aboveground samples located outside of the sulfide-rich areas. 

Metal concentrations in Level 1 discharge were among the 

highest measured in Elk Basin. All of these observations 

suggest that the presence of sulfide-rich mineralized rock 

is the primary control on dissolved metal concentrations 

and pH in ground water in the Standard Mine vicinity.

6. Waste-rock piles exert another major control on metal 

concentrations and pH. The lowest pH values and highest 

metal concentrations were typically observed in ground 

water discharging from waste-rock piles.

7. In addition to the control exerted by sulfide-rich bedrock, 

and waste rock piles, residence time also controlled major 

ion concentrations: higher specific conductance and major 

ion concentrations occur in older ground water.

8. Concentrations of many chemical constituents in addition to strontium isotope data indicate that the metals in 

sampled waters cannot be the primary source of metals in 

Level 1 discharge. Therefore, the primary source location 

of metals in Level 1 discharge was not found in this study. 

Possible source locations include either a zone of rock 

more highly mineralized than any observed in this study 

or a zone of mineralized rock similar to that observed but 

in a form that is highly conducive to metals dissolution, 

such as rubble or debris in the mine workings. Either 

source must be located below Levels 3 and 5 or farther 

back into the mountainside than the ends of Levels 3 

and 5.

9. The patterns of seasonal variations in field parameters, 

chemical constituents, and stable isotopes in Level 1 

discharge and Elk Creek are very similar. Estimated metal 

fluxes in Elk Creek in September 2006 are similar to or 

less than those in Level 1 discharge. Both of these observations are consistent with Level 1 discharge being the 

primary source of metals in Elk Creek.
64 Hydrogeochemical Investigation of the Standard Mine Vicinity, Upper Elk Creek Basin, Colorado

10. A prominent feature of the time-series data from both 

Level 1 discharge and Elk Creek was a “spring flush” during which pH dropped and metal concentrations rose in 

the early stages of spring runoff. δ18O and δ2H data along 

with the fact that the flush occurred during spring high 

flow suggest that the spring flush water originated from a 

shallow portion of the ground-water flow system or within 

the mine workings themselves. Reasonable candidate 

locations include pockets of high capillarity material 

(fine-grained fault gouge or intensely microfractured 

rock) within the seasonally saturated zone (unsaturated 

in winter, saturated in spring) near the ground surface or 

within portions of the mine workings that become saturated only during spring high flow.

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66
 67

Appendix 1. Sampling and Analysis Plan
68 
 69

SAMPLING AND ANALYSIS PLAN

GEOHYDROLOGIC INVESTIGATIONS OF THE STANDARD MINE VICINITY

GUNNISON COUNTY, COLORADO

May 30, 2006

Prepared by:

Andrew Manning, Ph.D.

Phillip Verplanck, Ph. D.

U.S. Geological Survey

P.O. Box 25046, Mail Stop 964

Denver, CO 80225
70 Hydrogeochemical Investigation of the Standard Mine Vicinity, Upper Elk Creek Basin, Colorado

Introduction

This Sampling and Analysis Plan (SAP) describes ground- and surface-water sampling and analysis that will be conducted as 

part of a geohydrologic investigation of the Standard Mine site. Ground-water sampling will occur and surface-water sampling 

will begin during Summer 2006. Surface-water sampling will continue through Spring 2007.

Problem Statement

The U.S. Environmental Protection Agency (USEPA) has listed the Standard Mine in the Elk Creek drainage near Crested Butte, 

Colorado as a Superfund Site (Figure 1). Drainage from the Standard Mine enters Elk Creek, contributing loads of zinc, cadmium, copper and other metals. Elk Creek is a tributary to Coal Creek, which is part of the drinking-water supply for the town 

of Crested Butte. The Standard Mine is one of dozens of mines and prospects that cover both the north and south sides of Mount 

Emmons, but is among the few mine portals from which water continually drains. It has therefore become the focus of attention 

of concerned local citizens and the USEPA.

Decisions on remedial options will require an understanding of: (1) the source(s) of the high metal loads in ground-water discharge from the Standard Mine, and potentially other parts of the upper Elk Creek basin; (2) ground-water flow paths leading to, 

and in the vicinity of, the Standard Mine; and (3) the residence time of ground water following these flow paths. Ground-water 

residence time is particularly important because it controls the degree to which mine discharge volumes and chemistry will vary 

in response to the dramatic seasonal and climatic cycles characteristic of alpine settings. These variations are a critical factor in 

formulating remediation strategies and treatment plant design. The geohydrologic investigation is designed to gain the greatest 

understanding of the metals source(s), ground-water flow paths, and residence times in the vicinity of the Standard Mine that is 

possible within assumed cost limitations. 

Data Quality Objectives

1. Determine where in the Elk Creek basin metal-rich water discharges, the concentrations of metals in these waters, and 

how these compare to metal concentrations in the Standard Mine discharge. 

2. Determine the primary source(s) of the elevated metal concentrations, and where and how the Standard Mine intersects 

the metal source(s).

3. Determine where in the basin there is sufficient permeability and fracture connectivity to allow significant groundwater flow, how/where these high-flow zones are connected and associated with metal sources, and how/where the 

Standard Mine intersects these high-flow zones.

4. Determine characteristic ground-water residence times and related temporal variations in the flow regime.

5. Determine the chemical signatures of the different waters that discharge into the Standard Mine.

Data Management

Data for the Standard Mine geohydrologic investigation will be obtained from a combination of sources, including field and 

laboratory measurements. The process of collecting and managing data is a coordinated effort and will be conducted by project 

staff and laboratories working closely together. Analytical results will be provided in an electronic spreadsheet format and will 

be tabulated in report form. All raw analytical data will be archived in an electronic format. Data quality will be examined before 

results are presented or used in subsequent activities. The laboratory will confirm sample receipt, sample condition, and required 

analyses.
Appendix 1 71

Types, Numbers, and Locations of Samples to Be Collected

Table 1 summarizes information on the different sample types, including bottle sizes, filtration, and types of analyses to be performed. 

Table 1. Sample Types.

Type of sample Bottle Size Filtration Analyses

Raw, acidified (RA) 30 mL None Total recoverable metals

Filtered, unacidified (FU) 125 mL Field filtered,

 0.45 μm Anions, alkalinity

Filtered, HNO3 acidified (FA) 125 mL Field filtered,

 0.45 μm

Dissolved metals, 

 Strontium isotopes

Filtered, HCl acidified(FAHCl) 60 mL Field filtered

 0.45 μm Dissolved iron species

Filtered, unacidified (C isotopes) 1 L Field filtered

 0.45 μm Carbon isotopes

Raw, unacidified (HO isotopes) 10 mL None Water isotopes

Raw, unacidified (Tritium) 500 mL None Tritium

Raw, unacidified (Dissolved gases) 15 ml (clamped copper tube) None Dissolved gases

Field sampling has been broken into three different tasks. Task 1 will involve collecting surface- and ground-water samples from 

4 different sites multiple times over the course of a year. These sites include the portal of the Standard Mine, Elk Creek just 

above its confluence with Coal Creek, and two additional ground-water sampling sites located in upper Elk Creek Basin. These 

two additional ground-water sites will most likely be springs, and their specific locations will be determined in the field. Table 2 

lists which types of samples will collected and when from the 4 different sites.
72 Hydrogeochemical Investigation of the Standard Mine Vicinity, Upper Elk Creek Basin, Colorado

Table 2. Task 1 Sample Collection Schedule.

Sampling 

Event

Standard 

Mine 

Portal

Elk 

Creek

Ground-water

Site 1

Ground-water

Site 2

Summer 2006 RA, FU, FA, FAHCl, HO Isotopes RA, FU, FA, HO 

Isotopes

Fall 2006 RA, FU, FA, FAHCl, HO Isotopes RA, FU, FA, HO 

Isotopes

RA, FU, FA, FAHCl, 

HO Isotopes

RA, FU, FA, FAHCl, 

HO Isotopes

Early Winter 2006/2007 RA, FU, FA, FAHCl, HO Isotopes RA, FU, FA, HO 

Isotopes

Late Winter 2007 RA, FU, FA, FAHCl, HO Isotopes RA, FU, FA, HO 

Isotopes

High Flow 1 Spring 2007 RA, FU, FA, FAHCl, HO Isotopes RA, FU, FA, HO 

Isotopes

High Flow 2 Spring 2007 RA, FU, FA, FAHCl, HO Isotopes RA, FU, FA, HO 

Isotopes

High Flow 3 Spring 2007 RA, FU, FA, FAHCl, HO Isotopes RA, FU, FA, HO 

Isotopes

RA, FU, FA, FAHCl, 

HO Isotopes

RA, FU, FA, FAHCl, 

HO Isotopes

High Flow 4 Spring 2007 RA, FU, FA, FAHCl, HO Isotopes RA, FU, FA, HO 

Isotopes

Task 2 will involve collecting ground-water samples (one-time) from about 20-30 locations in the upper Elk Creek Basin. Sampling sites will include springs, discharging mines, and flooded shafts, the locations of which will be determined in the field. The 

number and type of samples to be collected include: 20 to 30 samples for major and trace constituents (RA, FU, FA, FAHCl); 20 

samples for Sr isotopes (FA); 20 samples for tritium and dissolved gases; and up to 2 samples for C isotopes.

Task 3 will involve collecting ground-water samples (one-time) from 5-10 locations within the Standard Mine. Specific sampling 

locations will be determined in the field. The number and type of samples to be collected include: 10 samples for major and trace 

constituents (RA, FU, FA, FAHCl); 7 samples for Sr isotopes (FA); and 5 samples for tritium and dissolved gases. 

Field duplicate samples and equipment blanks will be collected at a rate of one for every ten locations sampled. Equipment 

blanks will be collected on filters. 

Sample Identification and Labeling

Each water sample will be clearly labeled for easy identification. An adhesive label will be affixed to each sample container. All 

labels will be written with permanent, waterproof markers. The label will convey the following information:

•	 sample identification code

•	 sample date and time 

•	 filtered or unfiltered sample

•	 preservative used, if any
Appendix 1 73

The label will contain an identification code that is unique for each sample. The identification code on the label will convey 

the following information: Site name, site type, number of times site has been sampled, and replicate information. The form of 

the identification code is “EC-XXXXX-00-X,” where X and 0 denote letter and numeric symbols, respectively. 

Identification codes are created as follows:

EC indicates: Drainage where site is located, in this case Elk Creek.

XXXXX indicates: Site name, which may include letters or numbers. The first character will always be a letter 

indicating the site type: C = creek; S = spring; M = mine discharge; etc.

00 indicates: Number in a sequence referring to how many times the site has been sampled: 01 = first 

time; 02 = second time; etc.

X indicates: Replicate information: A = first replicate; B = second replicate (sample locations with no 

replicates will not get an A or B).

Identification codes for equipment blank samples will have the form “EB-00”, where “EB” indicates “equipment blank” and 

“00” is the number in a sequence to be created as sample collection progresses.

The type of analysis or analyses to be conducted on the sample will also be noted on the sample label. All other sample collection information will be written on field sheets with the same ID code (see Attachment A).

Field Sampling Protocols

Sample Site Selection

For Task 1, the sampling site at the portal of the Standard Mine will be located as close to the portal as possible. The Elk Creek 

stream sample location will be located as close to the confluence with Coal Creek as possible, and will afford safe, convenient 

sample collection from the stream bank (without wading) during all seasons.

Task 2 sample sites will be selected based on several criteria. An attempt will be made to spatially distribute sites as evenly as 

possible throughout the Standard Mine vicinity, and to distribute sites among the different geologic features (rock types, faults, 

etc.) potentially controlling ground-water flow. If different types of water become evident based on field parameters, an attempt 

will be made to include sites representing all observed water types. If different site types can be sampled (different types of 

springs, mine discharge waters, and open mine shafts), an attempt will be made to include different site types. All sites must 

allow safe and relatively convenient access. Samples will only be collected from those sites that allow for the collection of a 

quality sample (for example, a quality dissolved gas sample cannot be collected from a very low-flow spring or seep). If field 

observations suggest that a site located in a drainage adjacent to Elk Creek would be useful, then this site might be selected.

In selecting Task 3 sample sites, the highest priority will be given to inflows with the highest flow rates and the lowest pH 

values. If multiple types of geologic features appear to be controlling inflows, then an attempt will be made to select inflows 

associated with the different features. An attempt will also be made to spread the sites as evenly as possible spatially. The most 

significant inflows, based on flow rate and pH, will be selected for the sampling of integrated mine drainage water immediately 

upstream and downstream of the inflow.

Field Parameters

At each sample location, field measurements of pH, specific conductance, dissolved oxygen, and temperature will be made at the 

time of sample collection. All field measurements will be recorded in a dedicated field notebook or on sample field sheets. All 

field monitoring equipment will be operated according to manufacturer’s instructions.
74 Hydrogeochemical Investigation of the Standard Mine Vicinity, Upper Elk Creek Basin, Colorado

Sample Collection

Table 3 lists the types and sizes of bottles used for sample collection, the bottle cleaning methods, filtration, and preservation for analytes. All bottles other than those cleaned by rinsing with sample water will be cleaned at the USGS laboratories. 

Sample filtration and preservation will be performed at the sampling site.

Table 3. Bottle type and size, cleaning, filtration, and preservation for analytes.

Analytes Bottle Type Bottle Size Cleaning Filtration Preservative

Total recoverable metals HDPE 30 mL 10% HNO3

 soak overnight, 

rinse 3x w/ DIW None HNO3

 to pH<2

Anions HDPE 125 mL Soak overnight in DIW 0.45-μm None

Alkalinity HDPE (in anions 

bottle) Soak overnight in DIW 0.45-μm None

Dissolved metals HDPE 125 mL 10% HNO3

 soak overnight, 

rinse 3x w/ DIW 0.45-μm HNO3

 to pH<2

Dissolved iron species Amber polyethylene 60 mL 10% HCl soak overnight, 

rinse 3x w/ DIW 0.45-μm HCl to pH<2, on ice, 4oC

Strontium isotopes HDPE (in metals 

bottle)

10% HNO3 soak overnight, 

rinse 3x w/ DIW 0.45-μm HNO3

 to pH<2

Carbon Isotopes Safety-coated glass with 

septum cap

1 L Rinse with sample water 0.45-μm None, on ice, 4oC

Water Isotopes Borosilicate glass 10 mL Rinse with sample water None None

Tritium HDPE 500 mL Rinse with sample water None None

Dissolved

Gases 5/8” copper tubing 15 mL Rinse with sample water None None

HDPE = high density polyethylene

DIW = distilled water

Samples collected from springs and discharging mines will be collected as close as possible to the emanation point – i.e., the actual 

orifice through which water discharges from the ground. Sampling gloves will be worn while sample bottles are being filled. For all 

samples except dissolved gas samples, bottles will be triple-rinsed using the following procedure:

1. open bottle and partially fill it with the water to be sampled (filtered if necessary)

2. close the cap and shake it vigorously

3. empty bottle downstream of the sample location

4. repeat 2 more times.

An effort will be made to minimize all physical contact with the water to be sampled while bottles are being filled. If entering 

the water is necessary in order to fill bottles, the person collecting the sample will stand downstream of the point where sample 

bottles are filled. Sample filtration procedures are described in section 7.4.

C isotope bottles will be filled using the following procedure.

1. Use a peristaltic or small submersible (centrifugal) pump to transfer water from the sampling point to the bottle. Submerge 

pump intake at the sample point, keeping it off the bottom so as to avoid pumping in sediment.

2. Turn on pump and allow to run for at least 2 minutes to purge the sample tubing.
Appendix 1 75

3. Turn off pump and install a disposable 0.45 μm in-line filter in the sample line. Turn pump back on and allow to run at least 

15 seconds to purge the filter. After sample line is purged, triple rinse sample bottle with filtered water.

4. Place discharge end of the sample tubing at the bottom of the sample bottle, thus allowing the bottle to fill from the bottom. 

Let the bottle overflow and continue overflowing for at least 1 minute.

5. Carefully remove the discharge end of the sample tubing from the bottle. Leave a 1-2mm head space.

6. Cap bottle with septum cap. Secure the cap by wrapping with electrical tape.

7. Affix a sample label with all required information. In addition to the standard information, the sample label will list the 

field pH and alkalinity. Field alkalinity will be obtained immediately before or after sample collection using a standard field 

alkalinity test kit, following all manufacturer’s instructions.

8. Repeat for a second bottle that is to be archived as a back-up in case of sample breakage. Use a cone-cap for this back-up 

sample instead of a septum cap.

9. Place bottles in cooler as soon as possible after filling.

Dissolved gas samples will be collected following the general guidelines described in Stute and Schlosser (2000). Samples will 

be collected in approximately 18” long sections of 3/8” diameter copper tubing. Water is sealed in the copper tubing with stainless steel pinch-off clamps. The following procedure will be used.

1. Use a peristaltic, small submersible (centrifugal), or vacuum hand pump to transfer water from the sampling point to the 

copper tube. This can also be done by siphoning. Submerge pump or intake tube at the sample point, keeping it off the bottom so as to avoid pumping in sediment.

2. Attach a pre-cut section of copper tubing at the end of the discharge tube. Attach a section of clear plastic tubing to the 

downstream end of the copper tubing. All fittings must create a tight seal to prevent leakage. Preset pinch-off clamps on the 

copper tubing so they are in place and ready to close.

3. Turn on pump or begin siphoning. Immediately tip copper tube upright (downstream-end up) and tap the copper tubing 

gently and repeatedly along its length with a wrench (or something similar) to force any trapped air bubbles to dislodge and 

flow out.

4. Allow water to run through the sample line for at least 1 minute to purge the copper tube. While purging, check the clear 

plastic tubing downstream of copper tubing to ensure that it is free of bubbles.

5. After purging, turn down the pump to low speed (unless siphoning) and close off the downstream end of the sample line by 

clamping the clear plastic tubing (alternately, a pre-installed valve in the plastic tubing can be closed).

6. Immediately close the downstream pinch-off clamp on the copper tube using a wrench. Alternate between the two bolts on 

either side of the clamp to avoid closing the clamp unevenly, which can cut the tube in a scissor-like fashion. After closing 

the downstream clamp completely, close the upstream clamp in the same way.

7. Remove the copper tubing from the sample line, fill the ends with sample water, and install end-caps.

8. Affix a sample label with all required information.

9. Care will be taken to not to bend the ends of the copper tubing that extend beyond the pinch-off clamps after the clamps are 

closed. These ends are delicate and will be handled with care during sample transport and storage.

Sample Filtration

Samples other than C isotope samples requiring filtration will be filtered at the sampling site using a disposable 0.45 μm syringe 

filter. Syringe filtration will be performed using the following procedure:

1. Put on disposable powderless gloves.

2. Fill syringe with sampling water and expel. 
76 Hydrogeochemical Investigation of the Standard Mine Vicinity, Upper Elk Creek Basin, Colorado

3. Fill syringe with sampling water, connect syringe filter, and pass approximately 30 mls through filter.

4. Rinse each sampling bottle that will receive filtered sample with filtered water. Cap bottle, shake to coat inner surfaces, 

remove cap, and empty out contents.

5. Fill bottles in the following order, leaving sufficient space in bottles for addition of preservative, if required:

a. Anions/alkalinity

b. Dissolved metals/Sr isotope

c. Dissolved iron species

6. If the filter medium clogs before the needed volume of water is filtered, replace with a new filter and note on field sheet. 

Repeat filter-rinsing process (step 3) with each new filter.

7. Add preservatives, as needed (see Table 3). Cap each bottle immediately and invert to incorporate preservative into sample.

8. Dry off sample bottles, complete labels, and affix appropriate labels to bottles. 

9. Place each sample bottle in a sealable bag and place in cooler or box, depending on required preservation.

10. Discard the used filter.

11. Document on field forms and in field notes any modifications to the filtration procedures used.

Preparation of Equipment Blanks

Equipment blanks will be prepared at a rate of 1 blank per 10 samples collected. Equipment blanks will be analyzed for total 

recoverable metals, anions (excluding alkalinity), dissolved metals, and dissolved iron species. Equipment blanks will be collected using the following procedure:

1. Put on disposable powderless gloves.

2. Fill syringe with double distilled water (DDW) and expel.

3. Fill syringe with DDW water, connect syringe filter, and pass approximately 30 mls through filter.

4. Rinse each blank bottle that will receive filtered sample with filtered DDW. Cap bottle, shake to coat inner surfaces, remove 

cap, and empty out contents

5. Fill one bottle for each set of analytes to be determined. 

6. Add preservatives, as needed (see Table 3). Cap each bottle immediately and invert to incorporate preservative into sample.

7. Dry off sample bottles, complete labels, and affix appropriate labels to bottles. 

8. Place each sample bottle in a sealable bag and place in cooler or box, depending on required preservation.

Duplicate Samples

Duplicate samples will be prepared at a rate of one per 10 locations sampled, Duplicate samples will be collected using the same 

procedure as the sample being duplicated, and will be analyzed for the same analytes.

Field Documentation

The field sampling team will document its sampling activities in dedicated, paginated, bound field notebooks. Entries will be 

made in waterproof ink, and corrections will be made with a single line through the error accompanied by the correction date 

and corrector’s initials. The notebook(s) will be kept in possession of the field sampling team at all times in the field. At the 
Appendix 1 77

conclusion of the field investigation, the notebook(s) will be stored in a secure office location. Information recorded in the field 

notebook will include:

•	 a general description of activities performed on site, including personnel on site and times and locations of work 

activities

•	 work conditions, including weather and any difficulties encountered

•	 observations and data not related to sampling, such as geologic observations, structural measurements, etc.

•	 any additional information relevant to sampling that is not recorded on sample sheets (see below)

Prepared sample sheets (see Attachment A) will be used by the sampling team. The following information will be recorded at 

each sample site either in the field notebook(s) or on the sample sheets:

•	 site and project name

•	 each person’s name in the sampling crew

•	 date and time of sample collection, weather conditions

•	 description of sample location using available landmarks and GPS-measured coordinates

•	 description of sample site characteristics, including surface stream characteristics, spring flow characteristics, etc.

•	 identification number(s) of sample(s) collected and the container (volume, type) used for each sample

•	 field parameter measurements

•	 any difficulties encountered or necessary deviations from the SAP during sample collection

•	 a description of each photograph taken

•	 any other pertinent field observations.

After each day’s field sampling, the notes will be reviewed by the sampler and any necessary corrections will be made. Photographs of each sample location will be taken.

Sample Preservation, Storage, Shipping and Custody

Preservation and Storage

Requirements for sample preservation are given in Table 3. All samples will be collected and stored in pre-cleaned sample 

bottles. Ultrapure nitric and hydrochloric acid will be used for preservation of metals samples.

Shipping and Custody

All sample bottles will be placed in resealable plastic storage bags. Samples will be stored on ice at 4oC, if required, until 

samples are transported to the laboratories. Total and dissolved metals/cations samples may be transported at either ambient 

temperatures or 4°C, as needed to conserve cooler space. For transport to the laboratory, samples will be placed in a cooler with 

ice (double bagged using plastic trash bags or ziplock bags) or a box, as required for preservation. Protective packing material 

will be used if appropriate to ensure that no breakage occurs during shipment. 

The field sampler is personally responsible for the care and custody of the samples until they are transferred to storage coolers. 

Samples will be stored in storage coolers in a locked room until they are transported to the laboratories. Samples will be transported to the USGS laboratories in Denver in locked field vehicles. C isotope samples will be shipped via FedEx from the USGS 
78 Hydrogeochemical Investigation of the Standard Mine Vicinity, Upper Elk Creek Basin, Colorado

office in Denver to the University of Waterloo Laboratory, who performs the carbon extractions. The University of Waterloo then 

ships the extracted carbon samples to the University of Arizona for analysis. 

Analytical Measurements

Major and Trace Constituent Chemistry

Analyses for total recoverable metals, anions and alkalinity, dissolved metals, and dissolved iron species will be performed in 

USGS laboratories in Denver or Boulder, Colorado. The following parameters will be measured: (1) major cations and anions; 

(2) total and dissolved trace and minor metals; and (3) dissolved iron species. The analytical method, reference, and detection 

limit for each parameter is listed in Table 4A and 4B.

Table 4A. Analytical methods and reporting limits in mg/L.

Parameter Method Reference Reporting Limit

(mg/L)

Calcium (Ca) ICP Taggart, 2002 0.1

Magnesium (Mg) ICP Taggart, 2002 0.1

Strontium (Sr) ICP Taggart, 2002 0.001

Barium (Ba) ICP Taggart, 2002 0.001

Sodium (Na) ICP Taggart, 2002 0.1

Aluminum (Al) ICP Taggart, 2002 0.01

Silica (SiO2) ICP Taggart, 2002 0.1

Alkalinity Titration Taggart, 2002 1.0

Chloride (Cl) IC Taggart, 2002 0.4

Fluoride (F) IC Taggart, 2002 0.4

Sulfate (SO4) IC Taggart, 2002 0.8

Iron (total) (Fe) Colorimetric To et al., 1999 0.001

Iron (II) Colorimetric To et al., 1999 0.002

ICP = inductively coupled argon plasma

IC = Ion chromatography

Sr Isotopes

Strontium isotopic analyses will be performed at the USGS in Denver, Colorado. In a clean environment, an aliquot of the water 

sample will be poured into a Teflon beaker and evaporated to dryness. The residue will be redissolved in ultrapure 2N HNO3

and eluted on a cation exchange column to separate the Sr from the other constituents in the sample. The Sr separate will be 
Appendix 1 79

Table 4B. Analytical methods and reporting limits in μg/L.

Parameter Method Reference Reporting Limit

(μg/L)

Lithium (Li) ICP-MS Taggart, 2002 0.9

Beryllium (Be) ICP-MS Taggart, 2002 0.05

Aluminum (Al) ICP-MS Taggart, 2002 2

Phosphorous (P) ICP-MS Taggart, 2002 10

Potassium (K) ICP-MS Taggart, 2002 30

Scandium (Sc) ICP-MS Taggart, 2002 0.6

Titanium (Ti) ICP-MS Taggart, 2002 0.5

Vanadium (V) ICP-MS Taggart, 2002 0.5

Chromium (Cr) ICP-MS Taggart, 2002 1

Manganese (Mn) ICP-MS Taggart, 2002 0.2

Cobalt (Co) ICP-MS Taggart, 2002 0.02

Nickel (Ni) ICP-MS Taggart, 2002 0.4

Copper (Cu) ICP-MS Taggart, 2002 0.5

Zinc (Zn) ICP-MS Taggart, 2002 0.5

Arsenic (As0 ICP-MS Taggart, 2002 1

Rubidium (Rb) ICP-MS Taggart, 2002 0.01

Strontium (Sr) ICP-MS Taggart, 2002 0.5

Yttrium (Y) ICP-MS Taggart, 2002 0.01

Niobium (Nb) ICP-MS Taggart, 2002 0.2

Molybdenum (Mo) ICP-MS Taggart, 2002 2

Silver (Ag) ICP-MS Taggart, 2002 0.3

Cadmium (Cd) ICP-MS Taggart, 2002 0.02

Antimony (Sb) ICP-MS Taggart, 2002 0.3

Cesium (Cs) ICP-MS Taggart, 2002 0.02

Barium (Ba) ICP-MS Taggart, 2002 0.2

Lanthanum (La) ICP-MS Taggart, 2002 0.01

Cerium (Ce) ICP-MS Taggart, 2002 0.01

Praseodymium (Pr) ICP-MS Taggart, 2002 0.01

Neodymium (Nd) ICP-MS Taggart, 2002 0.01

Samarium (Sm) ICP-MS Taggart, 2002 0.01

Europium (Eu) ICP-MS Taggart, 2002 0.005

Terbium (Tb) ICP-MS Taggart, 2002 0.005

Gadolinium (Gd) ICP-MS Taggart, 2002 0.005

Dysprosium (Dy) ICP-MS Taggart, 2002 0.005

Holmium (Ho) ICP-MS Taggart, 2002 0.005

Erbium (Er) ICP-MS Taggart, 2002 0.005

Thulium (Tm) ICP-MS Taggart, 2002 0.005

Ytterbium (Yb) ICP-MS Taggart, 2002 0.005

Lutetium (Lu) ICP-MS Taggart, 2002 0.1

Tantalum (Ta) ICP-MS Taggart, 2002 0.02

Tungsten (W) ICP-MS Taggart, 2002 0.5

Thallium (Tl) ICP-MS Taggart, 2002 0.1

Lead (Pb) ICP-MS Taggart, 2002 0.05

Bismuth (Bi) ICP-MS Taggart, 2002 0.2

Thorium (Th) ICP-MS Taggart, 2002 0.2

Uranium (U) ICP-MS Taggart, 2002 0.1

ICP-MS = Inductively coupled argon plasma – mass spectrometry
80 Hydrogeochemical Investigation of the Standard Mine Vicinity, Upper Elk Creek Basin, Colorado

collected in a Teflon beaker. The strontium isotopic composition of each separate will be measured on a Nu Instruments HR 

multi-collector ICP-MS. During each analytical run, a Sr standard reference (SRM987) will be measured periodically. Precision 

is generally less than +/- 0.00003. At least one duplicate will be prepared and analyzed with each set of samples.

C Isotopes

Carbon isotope analyses will be performed at the University of Arizona Accelerator Mass Spectrometry Laboratory in Tucson, 

Arizona. Samples will be analyzed for carbon-14 and carbon-13/carbon-12 ratio by accelerator mass spectrometry. Analytical methods are described in Donahue et al. (1990). Measurement precision for carbon-14 is typically less than +/- 0.5 percent 

modern carbon. 

Water Isotopes

Water isotope analyses will be performed by the USGS Stable Isotope Laboratory in Denver, Colorado.

Deuterium

Sample preparation for deuterium analysis of water is carried out offline in batch process by zinc reduction (Kendall and Coplen 

1985). Specifically, 2 μL of sample is condensed under liquid nitrogen temperatures in butt-sealed pyrex tubes containing 

approximately 60 mg of Indiana zinc. Following cryogenic purification of the sample, the tube is flame sealed and heated in a 

muffle furnace at 500°C for 30 minutes. Sample H2 gas is admitted to a Thermo-Finnigan 252 mass spectrometer and deuterium 

measured by dual inlet viscous flow. Samples are compared to reference gas of known isotopic composition and final δ2H values 

scaled against V-SMOW by post correcting against internal lab standards prepared offline in a similar fashion.

Precision is generally less than +/- 1.5 per mil. At least one set of sample duplicates is prepared in each batch on the zinc line to 

monitor measurement precision. Each sample is cycled 8 times in the mass spectrometer to produce a statistically robust average measurement for the sample, and the multiple cycles are checked for consistency and outliers are identified. Each sample 

is plotted versus δ18O values from the same sample, and samples that plot far from the global meteoric water line are flagged as 

potentially unreliable and in need of confirmation.

Oxygen-18

Sample preparation for δ18O analysis of water is performed in batch process by on-line equilibration with CO2, followed by 

isotopic analysis of the CO2 headspace gas. This is the classical method for δ18O first proposed by Epstein and Mayeda (1953), 

with slight modification to accommodate automated sample preparation and analysis. Water samples (200 μL) are dispensed 

into 2 mL borosilicate glass vials, purged with high purity CO2 in a glove bag and sealed with threaded septum-style caps prior 

to removal from the glove bag. Water-CO2 equilibration is facilitated by an isothermal heating block maintained at 40°C for 12 

hours. Following equilibration, headspace CO2 is extracted, purified, and admitted to a Micromass Optima mass spectrometer for 

δ18O -CO2 measurement by dual inlet viscous flow. Sample CO2 gas is compared to reference gas of known isotopic composition and final δ18O values scaled against V-SMOW by post correcting against internal lab standards prepared online in a similar 

fashion.

Precision is approximately +/- 0.05 per mil. Approximately one duplicate is run per 10 samples to monitor measurement precision. Each sample is cycled 8 times in the mass spectrometer to produce a statistically robust average measurement for the 

sample, and the multiple cycles are checked for consistency and outliers are identified. Each sample is plotted versus δ2H values 

from the same sample, and samples that plot far from the global meteoric water line are flagged as potentially unreliable and in 

need of confirmation.
Appendix 1 81

Tritium

Tritium analyses will be performed by the USGS Noble Gas Laboratory in Denver, Colorado using the 3He in-growth method 

(Bayer et al., 1989). Approximately 170 mL of sample is placed in a tritium extraction flask, degassed for 30 minutes under 

vacuum while being agitated using a heated ultrasonic bath, then sealed using a cold-welded crimp. The flask is then stored for 

approximately 100 days, allowing the accumulation of tritiogenically produced 3He. The flask is then attached to an ultra-high 

vacuum extraction line and the accumulated 3He is released and purified prior to being measured using a magnetic sector mass 

spectrometer (Mass Analyzer Products 215-50). The 3He concentration is determined by calibration to a known air standard that 

is run in conjunction with the sample set. Original 3H concentration at the time of sampling is calculated from the measured 3He 

concentration using the known decay constant (0.05621 yr-1) and the amount of time the extracted flask was stored. 

The detection limit is approximately 0.05 Tritium Units (TU), where 1 TU = 1 atom of 3H per 1018 atoms of hydrogen. Total 

pressure is checked upon sample inlet to verify that the flask did not leak during storage. Each sample is cycled 10 times in the 

mass spectrometer to produce a statistically robust measurement, and the multiple cycles are checked for consistency and outliers are 

identified.

Dissolved Gases

Dissolved gas analyses will be performed at the USGS Noble Gas Laboratory in Denver, Colorado. Dissolved gases are 

extracted from samples on an ultra-high vacuum extraction line. Major component gases (nitrogen, oxygen, carbon dioxide, 

and methane) are measured on a quadrupole mass spectrometer in dynamic operation mode. Major component gases are then 

removed by chemical reaction with a heated titanium/zirconium sponge, and remaining noble gases are separated cryogenically. 

Noble gas concentrations and isotopic compositions (He, 3He/4He ratio, Ne, Ar, Kr, and Xe) are measured using separate aliquots 

on a magnetic sector mass spectrometer (Mass Analyzer Products 215-50) run in static operation mode. Gas concentrations are 

determined by calibration to a known air standard. All gas concentrations are reported in units of cubic centimeters at standard 

temperature and pressure per gram of water (cm3STP/g).

Measurement uncertainties (1σ) typically are 2% for nitrogen, 2% for He, 1% for 3He/4He ratio, 3% for Ne, 2% for Ar, 3% for 

Kr, and 3% for Xe. Uncertainties for the other major component gases are considerably higher (approximately 10%), but these 

gases are analyzed only to screen samples for high levels of these gases, because unusually high levels can increase measurement uncertainty for nitrogen. Each sample tube is carefully checked prior to analysis for any signs of failed seals and any such 

signs are noted. Each gas aliquot is cycled 8-10 times in the mass spectrometer to produce a statistically robust measurement for the 

sample, and the multiple cycles are checked for consistency and outliers are identified. Oxygen levels are checked to verify that sample 

seals did not fail. The total pressure of extracted gases is checked upon initial inlet to evaluate the possibility of bubbles or leaks in the 

sample tube, or that all gases were not successfully extracted (due to ice blockages, etc.), and irregularities are noted.

References

Bayer, R., P. Schlosser, G. Bönisch, H. Rupp, F. Zaucker, and G. Zimmek, 1989, Performance and blank components of a mass 

spectrometric system for routine measurement of helium isotopes and tritium by the 3He ingrowth method, In Sitzungsberichte der Heidelberger Akademie der Wissenschaften, Mathematisch-naturwissenschaftliche Klasse, vol. 5: Heidelberg, 

Springer Verlag, p. 241-279.

Donahue, D.J., T.W. Linick, and A.J. Jull, 1990, Isotope-ratio and background corrections for accelerator mass spectrometry 

radiocarbon measurements, Radiocarbon, v. 32(2), p. 135-142

Epstein, S., and Mayeda, T, 1953, Variation of 18O content of waters from natural sources: Geochimica et Cosmochimica Acta, 

v. 4, p. 213-224.

Kendall, C., and Coplen, T.B., 1985, Multisample conversion of water to hydrogen by zinc for stable isotope determination: 

Analytical Chemistry, v. 57, p.1437-1440.

Stute, M., and Schlosser, P., 2000, Atmospheric noble gases, In P.G. Cook and A.L. Herczeg (Editors), Environmental Tracers in 

Subsurface Hydrology: Boston, Kluwer Academic Publishers, p. 349-377.
82 Hydrogeochemical Investigation of the Standard Mine Vicinity, Upper Elk Creek Basin, Colorado

Taggart, J.E. (ed.), 2002, Analytical methods for chemical analysis of geologic and other materials, U.S. Geological Survey, 

Open-File Report 02-0223.

To, B.T., Nordstrom, D. K., Cunningham, K.M., Ball, J.W., and McCleskey, R.B., 1999, New method for direct determination of 

dissolved Fe(III) concentrations in acid mine waters: Environmental Science and Technology, v. 33, p. 807-813.

Figure 1. Base map of the Mount Emmons area.

Mt. Emmons

Standard

Mine

Daisy

Mine

Keystone

Mine

Peeler Lakes

Copley

Lake Crested Butte

1 mile

1 km

N
 83

Attachment A: 

Field Sampling Sheet
84 Hydrogeochemical Investigation of the Standard Mine Vicinity, Upper Elk Creek Basin, Colorado
 85

Appendix 2. Sampling Information and 

Field Parameters
86 Hydrogeochemical Investigation of the Standard Mine Vicinity, Upper Elk Creek Basin, Colorado

Appendix 2. Sample information and field parameters.

[°C, degree Celsius; asl, above sea level; ft, feet; gpm, gallons per minute; mS/cm, microsiemens per centimeter; m, meters; mg/L, milligrams per liter; 14C, 

carbon-13 and carbon-14 isotopes; DG, dissolved gases; DO, dissolved oxygen; EB, equipment blank; Eh, redox potential; FA, filtered, acidified with nitric acid; 

FEHCL, filtered, acidified with hydrochloric acid; FU, filtered, unacidified; 3H, tritium; NA, not applicable; NM, not measured; –R (appended to sample name), 

replicate sample; RA, unfiltered, acidified with nitric acid; SAA, same as above; SC, specific conductance; SI, stable isotopes deuterium and oxygen-18; T, 

discharge temperature; UG, underground; V, volts]

Site Location1

Elevation

(ft asl)

Sample

name

Collection

date

Estimated

discharge

(gpm)

Field parameters

Name Description ID Easting

(m)

Northing

(m) pH Eh(V)

T

(°C)

Elk Creek Elk Creek near 

confluence 

with Coal 

Creek

EC–CELK1 321270 4302915 9,579 EC–CELK1–01 7/18/2006 NM 7.16 NM 7.9

EC–CELK1–02 10/9/2006 NM 6.94 NM 3.9

EC–CELK1–03 2/25/2007 NM 7.102 NM 0.5

EC–CELK1–04 4/14/2007 NM 7.392 NM 1.0

EC–CELK1–05 5/5/2007 NM 6.40 NM 1.0

EC–CELK1–06 5/15/2007 NM 6.12 NM 2.5

EC–CELK1–07 6/3/2007 NM 6.29 NM 7.4

EC–CELK1–08 6/17/2007 NM 6.78 NM 11.8

Tributary 1 Elk Creek 

Tributary

EC–T1 320458 4305961 11,416 EC–T1–01 8/15/2006 >10 7.70 0.490 16.0

EC–T1–02 8/20/2006 SAA NM NM 11.0

Tributary 2 Elk Creek 

Tributary

EC–T2 320455 4305941 11,404 EC–T2–01 8/15/2006 >10 7.68 0.503 13.9

EC–T2–02 8/20/2006 SAA NM NM 9.4

Tributary 3 Elk Creek 

Tributary

EC–T3 319954 4305479 11,021 EC–T3–01 8/17/2006 5–10 7.022 0.4252 12.4

EC–T3–02 8/20/2006 SAA NM NM 11.2

Spring 1 Discharge from 

waste rock 

outside Level 

5 portal

EC–S1 320610 4305936 11,510 EC–S1–01 8/15/2006 <1 3.18 NM 8.2

Spring 2 NA EC–S2 320669 4306012 11,580 EC–S2–01 8/15/2006 1–2 6.92 0.486 6.4

EC–S2–02 8/19/2006 SAA NM NM 6.9

EC–S2–02–R SAA SAA SAA SAA SAA

EC–S2–03 10/9/2006 NM 6.742 NM 4.8

EC–S2–04 6/17/2007 NM 6.76 NM 3.0

Spring 3 NA EC–S3 320543 4306331 11,663 EC–S3–01 8/15/2006 1 6.66 0.485 5.4

EC–S3–02 8/18/2006 SAA NM NM 5.6

Spring 4 NA EC–S4 320188 4306207 11,583 EC–S4–01 8/15/2006 2 7.40 0.467 3.9

EC–S4–02 8/19/2006 SAA NM NM 4.1
Appendix 2 87

Appendix 2. Sample information and field parameters.—Continued

[°C, degree Celsius; asl, above sea level; ft, feet; gpm, gallons per minute; mS/cm, microsiemens per centimeter; m, meters; mg/L, milligrams per liter; 14C, 

carbon-13 and carbon-14 isotopes; DG, dissolved gases; DO, dissolved oxygen; EB, equipment blank; Eh, redox potential; FA, filtered, acidified with nitric acid; 

FEHCL, filtered, acidified with hydrochloric acid; FU, filtered, unacidified; 3H, tritium; NA, not applicable; NM, not measured; –R (appended to sample name), 

replicate sample; RA, unfiltered, acidified with nitric acid; SAA, same as above; SC, specific conductance; SI, stable isotopes deuterium and oxygen-18; T, 

discharge temperature; UG, underground; V, volts]

Site Field parameters Samples collected

Name Description ID DO

(mg/L)

SC

(mS/cm) FU FA FEHCL 14C RA SI 3

H DG

Elk Creek Elk Creek near 

confluence 

with Coal 

Creek

EC–CELK1 8.29 132 x x x x x

8.93 129 x x x x

NM 1642 x x x x

NM 1242 x x x x

NM 79 x x x x

NM 70 x x x x

NM 86 x x x x

7.60 104 x x x x

Tributary 1 Elk Creek 

Tributary

EC–T1 6.36 30 x x x x

8.16 31 x

Tributary 2 Elk Creek 

Tributary

EC–T2 6.78 86 x x x x

8.42 86 x

Tributary 3 Elk Creek 

Tributary

EC–T3 6.25 522 x x x x

7.03 54 x

Spring 1 Discharge from 

waste rock 

outside Level 

5 portal

EC–S1 7.23 840 x x x x

Spring 2 NA EC–S2 8.20 91 x x x x

8.20 92 x x

SAA SAA x x

6.46 87 x x x x x

9.23 52 x x x x x

Spring 3 NA EC–S3 7.92 63 x x x x

8.12 55 x x

Spring 4 NA EC–S4 9.03 108 x x x x

9.16 126 x x
88 Hydrogeochemical Investigation of the Standard Mine Vicinity, Upper Elk Creek Basin, Colorado

Appendix 2. Sample information and field parameters.—Continued

[°C, degree Celsius; asl, above sea level; ft, feet; gpm, gallons per minute; mS/cm, microsiemens per centimeter; m, meters; mg/L, milligrams per liter; 14C, 

carbon-13 and carbon-14 isotopes; DG, dissolved gases; DO, dissolved oxygen; EB, equipment blank; Eh, redox potential; FA, filtered, acidified with nitric acid; 

FEHCL, filtered, acidified with hydrochloric acid; FU, filtered, unacidified; 3H, tritium; NA, not applicable; NM, not measured; –R (appended to sample name), 

replicate sample; RA, unfiltered, acidified with nitric acid; SAA, same as above; SC, specific conductance; SI, stable isotopes deuterium and oxygen-18; T, 

discharge temperature; UG, underground; V, volts]

Site Location1

Elevation

(ft asl)

Sample

name

Collection

date

Estimated

discharge

(gpm)

Field parameters

Name Description ID Easting

(m)

Northing

(m) pH Eh(V)

T

(°C)

Spring 5 NA EC–S5 320445 4306065 11,490 EC–S5–01 8/15/2006 <1 6.24 0.458 13.8

EC–S5–02 8/20/2006 SAA NM NM 12.2

Spring 7 NA EC–S7 319878 4305721 11,243 EC–S7–01 8/15/2006 2 7.22 0.484 5.2

EC–S7–02 8/20/2006 SAA NM NM 5.5

Spring 8A NA EC–S8A 320152 4305418 11,070 EC–S8A–01 8/16/2006 1–2 7.13 0.452 3.4

EC–S8A–02 8/20/2006 SAA NM NM 3.2

EC–S8A–03 10/9/2006 NM 6.56 NM 3.0

EC–S8A–04 6/17/2007 NM 7.31 NM 2.9

EC–S8A–04–R SAA SAA SAA SAA SAA

Spring 8B NA EC–S8B 320159 4305449 11,071 EC–S8B–01 8/16/2006 2 7.35 0.450 3.6

EC–S8B–02 8/20/2006 SAA NM NM 3.0

EC–S8B–02–R SAA SAA SAA SAA SAA

Spring 9 NA EC–S9 320282 4305608 11,174 EC–S9–01 8/16/2006 <1 6.38 0.474 5.5

EC–S9–02 8/19/2006 SAA NM NM 6.2

Spring 10 About 400 ft 

directly 

downhill from 

Spring 1

EC–S10 320526 4305857 11,433 EC–S10–01 8/16/2006 <1 4.71 0.571 11.9

Spring 11 Discharge from 

waste rock 

outside Elk 

Lode Mine 

portal

EC–S11 320345 4305912 11,356 EC–S11–01 8/17/2006 <1 6.20 0.425 13.4

EC–S11–01–R SAA SAA SAA SAA SAA

Spring 12 NA EC–S12 320157 4305229 10,990 EC–S12–01 8/17/2006 10 7.25 0.475 3.5

EC–S12–02 8/20/2006 SAA NM NM 3.3
Appendix 2 89

Appendix 2. Sample information and field parameters.—Continued

[°C, degree Celsius; asl, above sea level; ft, feet; gpm, gallons per minute; mS/cm, microsiemens per centimeter; m, meters; mg/L, milligrams per liter; 14C, 

carbon-13 and carbon-14 isotopes; DG, dissolved gases; DO, dissolved oxygen; EB, equipment blank; Eh, redox potential; FA, filtered, acidified with nitric acid; 

FEHCL, filtered, acidified with hydrochloric acid; FU, filtered, unacidified; 3H, tritium; NA, not applicable; NM, not measured; –R (appended to sample name), 

replicate sample; RA, unfiltered, acidified with nitric acid; SAA, same as above; SC, specific conductance; SI, stable isotopes deuterium and oxygen-18; T, 

discharge temperature; UG, underground; V, volts]

Site Field parameters Samples collected

Name Description ID DO

(mg/L)

SC

(mS/cm) FU FA FEHCL 14C RA SI 3

H DG

Spring 5 NA EC–S5 2.54 56 x x x x

2.86 61 x

Spring 7 NA EC–S7 6.81 72 x x x x

7.73 73 x x

Spring 8A NA EC–S8A 8.56 180 x x x x

9.51 178 x x

7.18 152 x x x x x

9.42 157 x x x x x

SAA SAA x

Spring 8B NA EC–S8B 8.32 180 x x x x

9.22 180 x x

SAA SAA x

Spring 9 NA EC–S9 6.36 109 x x x x

5.75 115 x x

Spring 10 About 400 ft 

directly 

downhill from 

Spring 1

EC–S10 2.82 187 x x x x

Spring 11 Discharge from 

waste rock 

outside Elk 

Lode Mine 

portal

EC–S11 6.67 57 x x x x

SAA SAA x x x x

Spring 12 NA EC–S12 8.85 230 x x x x

10.03 230 x x
90 Hydrogeochemical Investigation of the Standard Mine Vicinity, Upper Elk Creek Basin, Colorado

Appendix 2. Sample information and field parameters.—Continued

[°C, degree Celsius; asl, above sea level; ft, feet; gpm, gallons per minute; mS/cm, microsiemens per centimeter; m, meters; mg/L, milligrams per liter; 14C, 

carbon-13 and carbon-14 isotopes; DG, dissolved gases; DO, dissolved oxygen; EB, equipment blank; Eh, redox potential; FA, filtered, acidified with nitric acid; 

FEHCL, filtered, acidified with hydrochloric acid; FU, filtered, unacidified; 3H, tritium; NA, not applicable; NM, not measured; –R (appended to sample name), 

replicate sample; RA, unfiltered, acidified with nitric acid; SAA, same as above; SC, specific conductance; SI, stable isotopes deuterium and oxygen-18; T, 

discharge temperature; UG, underground; V, volts]

Site Location1

Elevation

(ft asl)

Sample

name

Collection

date

Estimated

discharge

(gpm)

Field parameters

Name Description ID Easting

(m)

Northing

(m) pH Eh(V)

T

(°C)

Level 2 

waste 

rock

Discharge from 

waste rock 

outside Level 

2 portal

EC–MUSTD1 320315 4305674 11,208 EC–MUSTD1–01 7/18/2006 <1 2.97 NM 10.0

Redwell 

spring 1

Located in Redwell BasinRW–S1 321500 4306706 11,065 RW–S1–01 8/18/2006 1 6.65 0.476 2.8

Redwell 

spring 2

"The Red Well," 

located in 

Redwell 

Basin

RW–S2 321671 4306947 10,782 RW–S2–01 8/18/2006 10 3.68 0.547 5.4

RW–S2–01–R SAA SAA SAA SAA SAA

Well 1 Flowing well 

located in 

Redwell 

Basin

RW–W1 321711 4306789 10,912 RW–W1–01 8/18/2006 10-20 NM NM 3.6

Pit 4 Exploration pit EC–P4 320416 4305759 11,335 EC–P4–01 8/16/2006 NA 5.60 0.491 13.4

Pit 5 Exploration pit EC–P5 320493 4305802 11,398 EC–P5–01 8/17/2006 NA 5.78 0.461 9.2

Level 1 

portal

Discharge 

from Level 

1 portal of 

Standard 

Mine

EC–MSTD1 320124 4305517 11,008 EC–MSTD1–01 7/18/2006 NM 5.62 NM 4.5

EC–MSTD1–02 8/16/2006 11 6.20 0.422 4.5

EC–MSTD1–02–R SAA SAA SAA SAA SAA

EC–MSTD1–03 10/9/2006 NM 5.58 NM 4.5

EC–MSTD1–03–R SAA SAA SAA SAA SAA

EC–MSTD1–04 2/25/2007 NM 6.602 NM 0.5

EC–MSTD1–05 4/14/2007 NM 6.682 NM 0.5

EC–MSTD1–06 5/5/2007 NM 4.03 NM 0.5

EC–MSTD1–07 5/15/2007 NM 3.56 NM 3.1

EC–MSTD1–08 6/3/2007 NM 3.42 NM 3.7

EC–MSTD1–09 6/17/2007 NM 3.84 NM 4.1

Level 1

 site 2

Standard Mine, 

Level 1, 

about 60 ft in 

fromportal at 

collapse

EC–MSTD2 UG UG UG EC–MSTD2–01 8/19/2006 NM NM NM 4.6
Appendix 2 91

Appendix 2. Sample information and field parameters.—Continued

[°C, degree Celsius; asl, above sea level; ft, feet; gpm, gallons per minute; mS/cm, microsiemens per centimeter; m, meters; mg/L, milligrams per liter; 14C, 

carbon-13 and carbon-14 isotopes; DG, dissolved gases; DO, dissolved oxygen; EB, equipment blank; Eh, redox potential; FA, filtered, acidified with nitric acid; 

FEHCL, filtered, acidified with hydrochloric acid; FU, filtered, unacidified; 3H, tritium; NA, not applicable; NM, not measured; –R (appended to sample name), 

replicate sample; RA, unfiltered, acidified with nitric acid; SAA, same as above; SC, specific conductance; SI, stable isotopes deuterium and oxygen-18; T, 

discharge temperature; UG, underground; V, volts]

Name Description ID

Field parameters Samples collected

DO

(mg/L)

SC

(mS/cm) FU FA FEHCL 14C RA SI 3

H DG

Level 2 

waste 

rock

Discharge from 

waste rock 

outside Level 

2 portal

EC–MUSTD1 5.60 773 x x x x x

Redwell 

spring 1

Located in Redwell BasinRW–S1 9.43 75 x x x x x x x x

Redwell 

spring 2

"The Red Well," 

located in 

Redwell 

Basin

RW–S2 0.54 249 x x x x x x x x

SAA SAA x x x x x x x x

Well 1 Flowing well 

located in 

Redwell 

Basin

RW–W1 0.18 618 x x

Pit 4 Exploration pit EC–P4 6.70 47 x x x x

Pit 5 Exploration pit EC–P5 6.90 78 x x x x

Level 1 

portal

Discharge from 

Level 1 portal 

of Standard 

Mine

EC–MSTD1 6.55 479 x x x x x

8.23 518 x x x x x

SAA SAA x x x x x

6.31 452 x x x x x

SAA SAA x x x x x

NM 6132 x x x x x

NM 5722 x x x x x

NM 485 x x x x x

NM 488 x x x x x

NM 453 x x x x x

8.40 442 x x x x x

Level 1 

site 2

Standard Mine, 

Level 1, 

about 60 ft in 

from portal at 

collapse

EC–MSTD2 8.01 470 x x
92 Hydrogeochemical Investigation of the Standard Mine Vicinity, Upper Elk Creek Basin, Colorado

Appendix 2. Sample information and field parameters.—Continued

[°C, degree Celsius; asl, above sea level; ft, feet; gpm, gallons per minute; mS/cm, microsiemens per centimeter; m, meters; mg/L, milligrams per 

liter; 14C, carbon-13 and carbon-14 isotopes; DG, dissolved gases; DO, dissolved oxygen; EB, equipment blank; Eh, redox potential; FA, filtered, 

acidified with nitric acid; FEHCL, filtered, acidified with hydrochloric acid; FU, filtered, unacidified; 3H, tritium; NA, not applicable; NM, not measured; 

–R (appended to sample name), replicate sample; RA, unfiltered, acidified with nitric acid; SAA, same as above SC, specific conductance; SI, stable 

isotopes deuterium and oxygen-18; T, discharge temperature; UG, underground; V, volts]

Site Location1

Elevation

(ft asl)

Sample 

name

Collection 

date

Estimated 

discharge 

(gpm)

Field parameters

Name Description ID Easting

(m)

Northing

(m) pH Eh(V)

T

(°C)

Level 3 

site 4

Standard Mine, 

Level 3, 386 

ft in from 

portal

EC–

MSTDL34

UG UG UG EC–

MSTDL34–01

8/17/2006 <1 6.95 0.567 4.2

Level 3 

site 5

Standard Mine, 

Level 3, 639 

ft in from 

portal

EC–

MSTDL35

UG UG UG EC–

MSTDL35–01

8/17/2006 <1 6.77 0.554 4.2

Level 5 

portal

Discharge 

from Level 

5 portal of 

Standard 

Mine

EC–

M11600

320667 4305941 11582 EC–

M11600–01

8/15/2006 2-3 6.66 0.384 3.6

EC–

M11600–02

8/19/2006 SAA NM NM 3.8

Level 5 

site 1

Standard Mine, 

Level 5, 546 

ft in from 

portal

EC–

M116001

UG UG UG EC–

M116001–01

8/17/2006 1–2 6.70 0.278 3.8

Level 5 

site 2

Standard Mine, 

Level 5, 228 

ft in from 

portal

EC–

M116002

UG UG UG EC–

M116002–01

8/17/2006 <1 7.20 0.354 3.6

Elk Lode 

portal

Discharge from 

portal of Elk 

Lode Mine

EC–

M11400B

320404 4305949 11380 EC–

M11400B–01

8/15/2006 1–2 6.28 0.462 7.5

EC–

M11400B–01–R

SAA SAA SAA SAA SAA

EC–

M11400B–02

8/20/2006 SAA NM NM 7.2

NA NA NA NA NA NA EB–01 8/15/2006 NA NA NA NA

NA NA NA NA NA NA EB–02 8/16/2006 NA NA NA NA

NA NA NA NA NA NA EB–03 8/18/2006 NA NA NA NA

NA NA NA NA NA NA EB–04 10/9/2006 NA NA NA NA

NA NA NA NA NA NA EB–05 6/20/2007 NA NA NA NA
Appendix 2 93

Appendix 2. Sample information and field parameters.—Continued

[°C, degree Celsius; asl, above sea level; ft, feet; gpm, gallons per minute; mS/cm, microsiemens per centimeter; m, meters; mg/L, milligrams 

per liter; 14C, carbon-13 and carbon-14 isotopes; DG, dissolved gases; DO, dissolved oxygen; EB, equipment blank; Eh, redox potential; FA, 

filtered, acidified with nitric acid; FEHCL, filtered, acidified with hydrochloric acid; FU, filtered, unacidified; 3H, tritium; NA, not applicable; NM, 

not measured; –R (appended to sample name), replicate sample; RA, unfiltered, acidified with nitric acid; SAA, same as above SC, specific 

conductance; SI, stable isotopes deuterium and oxygen-18; T, discharge temperature; UG, underground; V, volts]

Site Field parameters Samples collected

Name Description ID DO

(mg/L)

SC

(mS/cm) FU FA FEHCL 14C RA SI 3

H DG

Level 3 

site 4

Standard Mine, 

Level 3, 386 

ft in from 

portal

EC–

MSTDL34

8.74 188 x x x x x x

Level 3 

site 5

Standard Mine, 

Level 3, 639 

ft in from 

portal

EC–

MSTDL35

8.78 265 x x x x x x

Level 5 

portal

Discharge 

from Level 

5 portal of 

Standard 

Mine

EC–

M11600

8.55 215 x x x x

8.75 123 x

Level 5 

site 1

Standard Mine, 

Level 5, 546 

ft in from 

portal

EC–

M116001

3.62 302 x x x x x x x

Level 5 

site 2

Standard Mine, 

Level 5, 228 

ft in from 

portal

EC–

M116002

NM 241 x x x x x x

Elk Lode 

portal

Discharge from 

portal of Elk 

Lode Mine

EC–

M11400B

5.88 88 x x x x

SAA SAA x x x x

6.16 92 x x

NA NA NA NA NA x x x x

NA NA NA NA NA x x x x

NA NA NA NA NA x x x x

NA NA NA NA NA x x x x

NA NA NA NA NA x x x x

1

Coordinates are Universal Transverse Mercator (UTM) coordinate system, North American Datum of 1983, Zone 13S.

2

Not measured in situ, but generally within 12 hours of sampling and at a temperature <16°C.

 95

Appendix 3. Concentrations of Major Ions 

and Selected Metals
96 Hydrogeochemical Investigation of the Standard Mine Vicinity, Upper Elk Creek Basin, Colorado

Appendix 3. Concentrations of major ions and selected metals.

[°C, degrees Celsius; mS/cm, microsiemens per centimeter; meq/L, milliequivalents per liter; mg/L, milligrams per liter; C.I., charge imbalance; DO, dissolved 

oxygen; EB, equipment blank; Eh, redox potential; FA, filtered, acidified; Fe(II), ferrous iron; FU, filtered, unacidified; NC, not computed; NM, not measured; 

–R (appended to sample name), replicate sample; RA, unfiltered, acidified; SC, specific conductance; T, total; V, volts]

Property and 

constituent

Sample

EC–CELK1

–01

EC–CELK1

–01

EC–CELK1

–02

EC–CELK1

–02

EC–CELK1

–03

EC–CELK1

–03

EC–CELK1

–04

Property

Date 7/18/2006 10/9/2006 2/25/2007 4/14/2007

pH 7.16 6.94 7.1 7.39

SC (mS/cm) 132 129 164 124

Temperature (°C) 7.9 3.9 0.5 1

DO (mg/L) 8.29 8.93 NM NM

Eh (V) NM NM NM NM

Treatment FA/FU RA FA/FU RA FA/FU RA FA/FU

Constituent (mg/L)

Alkalinity as HCO3

– 41.7 NM 30.4 NM 43.3 NM 38.8

F <0.03 NM 0.06 NM <0.05 NM <0.05

Cl 0.05 NM 0.43 NM 0.15 NM 0.09

NO3 2.8 NM 0.08 NM 0.10 NM 0.10

SO4 25.1 NM 33.7 NM 40.6 NM 25.1

Ca 20.9 21.1 18.3 18.4 26.2 26.5 19.7

Mg 1.37 1.41 1.35 1.41 1.68 1.71 1.22

Na 1.69 1.68 1.44 1.44 2.05 2.09 1.56

SiO2 8.0 8.1 6.5 6.9 6.2 6.3 6.1

K1 0.38 0.38 0.43 0.49 0.45 0.46 0.44

Fe(T) 0.002 <0.02 <0.02 0.055 <0.02 0.027 <0.02

Fe(II) NM NM NM NM NM NM NM

Al1 <0.02 <0.02 0.027 0.035 <0.02 <0.02 <0.02

Mn1 0.014 0.019 0.163 0.188 <0.01 <0.01 0.030

Cu1 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01

Zn1 0.444 0.482 0.937 1.06 0.596 0.617 0.515

Pb1 <0.05 <0.05 <0.05 <0.05 <0.05 <0.05 <0.05

Cd 0.00220 0.00235 0.00517 0.00515 0.00270 0.00256 0.00236

Ni <0.0004 <0.0004 0.0006 0.0006 0.0004 0.0004 <0.0004

Ag <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001

Ba1 0.015 0.016 0.013 0.015 0.016 0.016 0.012

Sr1 0.165 0.179 0.149 0.172 0.245 0.252 0.190

B <0.005 <0.005 0.0039 <0.005 <0.005 <0.005 <0.005

Hardness (mg/L 

CaCO3)

58.0 NC 51.7 NC 72.6 NC 54.5

Sum cations (meq/L) 1.22 NC 1.10 NC 1.51 NC 1.15

Sum anions (meq/L) 1.22 NC 1.18 NC 1.50 NC 1.13

C.I. (%) 0.18 NC –3.48 NC 0.37 NC 1.00
Appendix 3 97

Appendix 3. Concentrations of major ions and selected metals.—Continued

[°C, degrees Celsius; mS/cm, microsiemens per centimeter; meq/L, milliequivalents per liter; mg/L, milligrams per liter; C.I., charge imbalance; DO, dissolved 

oxygen; EB, equipment blank; Eh, redox potential; FA, filtered, acidified; Fe(II), ferrous iron; FU, filtered, unacidified; NC, not computed; NM, not measured; 

–R (appended to sample name), replicate sample; RA, unfiltered, acidified; SC, specific conductance; T, total; V, volts]

Property and 

constituent

Sample

EC–CELK1

–04

EC–CELK1

–05

EC–CELK1

–05

EC–CELK1

–06

EC–CELK1

–06

EC–CELK1

–07

EC–CELK1

–07

Property

Date 5/5/2007 5/15/2007 6/3/2007

pH 6.4 6.12 6.29

SC (mS/cm) 79 70 86

Temperature (°C) 1 2.5 7.4

DO (mg/L) NM NM NM

Eh (V) NM NM NM

Treatment RA FA/FU RA FA/FU RA FA/FU RA

Constituent (mg/L)

Alkalinity as HCO3

– NM 23.6 NM 18.4 NM 23.4 NM

F NM <0.05 NM <0.05 NM <0.05 NM

Cl NM 0.07 NM 0.07 NM 0.08 NM

NO3 NM 0.08 NM 0.08 NM <0.05 NM

SO4 NM 16.1 NM 15.5 NM 19.1 NM

Ca 19.2 12.1 11.6 9.66 9.59 12.8 12.7

Mg 1.22 0.86 0.83 0.78 0.79 0.92 0.92

Na 1.55 1.19 0.83 1.04 0.95 1.31 1.22

SiO2 6.1 5.4 5.4 4.9 5.1 5.5 5.5

K 0.35 0.37 0.36 0.34 0.34 0.39 0.36

Fe(T) 0.036 0.046 0.217 0.054 0.428 0.041 0.142

Fe(II) NM NM NM NM NM NM NM

Al 0.026 0.033 0.135 0.044 0.201 0.044 0.095

Mn 0.032 0.116 0.116 0.170 0.185 0.111 0.121

Cu <0.01 <0.01 0.011 0.011 0.019 0.010 0.014

Zn 0.526 0.646 0.652 0.791 0.856 0.610 0.651

Pb <0.05 <0.05 <0.05 <0.05 <0.05 <0.05 <0.05

Cd 0.00232 0.00376 0.00366 0.00492 0.00488 0.00393 0.00381

Ni <0.0004 0.0005 0.0005 0.0008 0.0006 0.0005 0.0005

Ag <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001

Ba 0.012 0.0086 0.0087 0.0078 0.0086 0.010 0.011

Sr 0.183 0.098 0.094 0.070 0.074 0.089 0.090

B <0.005 <0.005 <0.005 <0.005 <0.005 <0.005 <0.005

Hardness (mg/L CaCO3) NC 34.1 NC 27.7 NC 36.1 NC

Sum cations (meq/L) NC 0.75 NC 0.63 NC 0.79 NC

Sum anions (meq/L) NC 0.71 NC 0.61 NC 0.77 NC

C.I. (%) NC 2.81 NC 0.88 NC 1.70 NC
98 Hydrogeochemical Investigation of the Standard Mine Vicinity, Upper Elk Creek Basin, Colorado

Appendix 3. Concentrations of major ions and selected metals.—Continued

[°C, degrees Celsius; mS/cm, microsiemens per centimeter; meq/L, milliequivalents per liter; mg/L, milligrams per liter; C.I., charge imbalance; DO, dissolved 

oxygen; EB, equipment blank; Eh, redox potential; FA, filtered, acidified; Fe(II), ferrous iron; FU, filtered, unacidified; NC, not computed; NM, not measured; 

–R (appended to sample name), replicate sample; RA, unfiltered, acidified; SC, specific conductance; T, total; V, volts]

Property and

constituent

Sample

EC–CELK1

–08

EC–CELK1

–08

EC–T1–01 EC–T1–01 EC–T2–01 EC–T2–01 EC–T3–01

Property

Date 6/17/2007 8/15/2006 8/15/2006 8/17/2006

pH 6.78 7.70 7.68 7.02

SC (mS/cm) 104 30 86 52

Temperature (°C) 11.8 16.0 13.9 12.4

DO (mg/L) 7.6 6.36 6.78 6.25

Eh (V) NM 0.490 0.503 0.425

Treatment FA/FU RA FA/FU RA FA/FU RA FA/FU

Constituent (mg/L)

Alkalinity as HCO3

– 30.3 NM 14.0 NM 19.7 NM 27.5

F <0.05 NM 0.03 NM 0.08 NM <0.03

Cl 0.08 NM 0.16 NM 0.08 NM 0.12

NO3 <0.05 NM <0.05 NM 0.07 NM 0.10

SO4 21.8 NM 2.99 NM 21.8 NM 3.61

Ca 15.9 15.8 4.45 4.46 10.9 11.1 8.19

Mg 1.07 1.06 0.39 0.39 1.21 1.21 0.58

Na 1.57 1.50 0.63 0.62 2.04 2.01 0.86

SiO2 6.2 6.2 4.0 4.2 9.4 9.6 5.7

K 0.40 0.39 0.23 0.26 0.43 0.42 0.41

Fe(T) 0.027 0.096 0.042 0.264 0.007 0.030 0.031

Fe(II) NM NM 0.042 NM 0.007 NM 0.020

Al 0.039 0.060 <0.02 0.051 <0.02 <0.02 <0.02

Mn 0.059 0.070 0.018 0.080 0.011 0.027 0.029

Cu <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01

Zn 0.419 0.438 <0.02 <0.02 0.032 0.038 <0.02

Pb <0.05 <0.05 <0.05 <0.05 <0.05 <0.05 <0.05

Cd 0.00279 0.00267 0.00006 0.00011 0.00012 0.00015 0.00002

Ni <0.0004 0.0004 <0.0004 <0.0004 <0.0004 <0.0004 <0.0004

Ag <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001

Ba 0.012 0.012 0.0049 0.0066 0.0040 0.0046 0.011

Sr 0.109 0.110 0.029 0.028 0.088 0.092 0.044

B <0.005 <0.005 <0.005 <0.005 0.0061 <0.005 <0.005

Hardness (mg/L CaCO3) 44.3 NC 12.9 NC 32.3 NC 23.0

Sum cations (meq/L) 0.95 NC 0.29 NC 0.73 NC 0.50

Sum anions (meq/L) 0.93 NC 0.30 NC 0.77 NC 0.53

C.I. (%) 1.38 NC –1.28 NC –2.53 NC –2.37
Appendix 3 99

Appendix 3. Concentrations of major ions and selected metals.—Continued

[°C, degrees Celsius; mS/cm, microsiemens per centimeter; meq/L, milliequivalents per liter; mg/L, milligrams per liter; C.I., charge imbalance; DO, dissolved 

oxygen; EB, equipment blank; Eh, redox potential; FA, filtered, acidified; Fe(II), ferrous iron; FU, filtered, unacidified; NC, not computed; NM, not measured; 

–R (appended to sample name), replicate sample; RA, unfiltered, acidified; SC, specific conductance; T, total; V, volts]

Property and 

constituent

Sample

EC–T3

–01

EC–S1

–01

EC–S1

–01

EC–S2

–01

EC–S2

–01

EC–S2

–03

EC–S2

–03

Property

Date 8/15/2006 8/15/2006 10/9/2006

pH 3.18 6.92 6.74

SC (mS/cm) 840 91 87.2

Temperature (°C) 8.2 6.4 4.8

DO (mg/L) 7.23 8.20 6.46

Eh (V) NM 0.486 NM

Treatment RA FA/FU RA FA/FU RA FA/FU RA

Constituent (mg/L)

Alkalinity as HCO3

– NM NM NM 19.5 NM 17.7 NM

F NM 0.13 NM 0.07 NM 0.06 NM

Cl NM 0.16 NM 0.16 NM 0.13 NM

NO3 NM <0.05 NM 0.41 NM 0.43 NM

SO4 NM 318 NM 25.7 NM 25.2 NM

Ca 8.46 36.5 39.6 11.3 11.5 11.0 11.2

Mg 0.59 9.37 9.88 1.33 1.34 1.28 1.27

Na 0.84 2.36 2.39 2.04 2.01 2.66 1.92

SiO2 5.9 23.4 25.1 10.4 10.7 9.3 9.7

K 0.39 0.85 0.99 0.49 0.52 1.67 0.45

Fe(T) 0.438 2.36 2.73 0.002 <0.02 0.003 <0.02

Fe(II) NM 0.028 NM <0.002 NM 0.003 NM

Al 0.077 11.0 12.0 <0.02 <0.02 <0.02 <0.02

Mn 0.059 23.0 26.0 <0.01 <0.01 <0.01 <0.01

Cu <0.01 0.617 0.681 <0.01 <0.01 <0.01 <0.01

Zn <0.02 25.0 28.0 0.102 0.110 0.162 0.102

Pb <0.05 1.18 1.23 <0.05 <0.05 <0.05 <0.05

Cd 0.00003 0.197 0.186 0.00052 0.00051 0.00067 0.00047

Ni <0.0004 0.0252 0.0238 <0.0004 <0.0004 0.0030 <0.0004

Ag <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001

Ba 0.013 0.023 0.026 0.0077 0.0083 0.0090 0.0075

Sr 0.052 0.221 0.259 0.091 0.092 0.077 0.093

B <0.005 <0.005 <0.005 <0.005 <0.005 0.0062 <0.005

Hardness (mg/L CaCO3) NC 172 NC 33.8 NC 32.8 NC

Sum cations (meq/L) NC 5.12 NC 0.76 NC 0.80 NC

Sum anions (meq/L) NC 5.25 NC 0.85 NC 0.81 NC

C.I. (%) NC –1.23 NC –5.56 NC –0.54 NC
100 Hydrogeochemical Investigation of the Standard Mine Vicinity, Upper Elk Creek Basin, Colorado

Appendix 3. Concentrations of major ions and selected metals.—Continued

[°C, degrees Celsius; mS/cm, microsiemens per centimeter; meq/L, milliequivalents per liter; mg/L, milligrams per liter; C.I., charge imbalance; DO, dissolved 

oxygen; EB, equipment blank; Eh, redox potential; FA, filtered, acidified; Fe(II), ferrous iron; FU, filtered, unacidified; NC, not computed; NM, not measured; 

–R (appended to sample name), replicate sample; RA, unfiltered, acidified; SC, specific conductance; T, total; V, volts]

Property and

constituent

Sample

EC–S2

–04

EC–S2

–04

EC–S3

–01

EC–S3

–01

EC–S4

–01

EC–S4

–01

EC–S5

–01

Property

Date 6/17/2007 8/15/2006 8/15/2006 8/15/2006

pH 6.76 6.66 7.40 6.24

SC (mS/cm) 52 63 108 56

Temperature (°C) 3 5.4 3.9 13.8

DO (mg/L) 9.23 7.92 9.03 2.54

Eh (V) NM 0.485 0.467 0.458

Treatment Fa/FU RA FA/FU RA FA/FU RA FA/FU

Constituent (mg/L)

Alkalinity as HCO3

– 13.4 NM 22.3 NM 38.0 NM 28.0

F <0.05 NM 0.07 NM 0.03 NM 0.03

Cl 0.08 NM 0.06 NM 0.07 NM 0.21

NO3 0.50 NM 0.14 NM 0.33 NM 0.13

SO4 12.8 NM 11.9 NM 20.0 NM 5.90

Ca 6.69 6.62 9.07 9.51 17.2 17.3 8.66

Mg 0.75 0.74 0.67 0.68 0.78 0.82 0.58

Na 1.58 1.25 1.11 1.11 1.53 1.56 0.92

SiO2 7.5 7.5 7.1 7.7 7.9 8.2 6.7

K 0.37 0.33 0.30 0.32 0.27 0.24 0.60

Fe(T) <0.02 <0.02 <0.002 <0.02 <0.002 <0.02 0.015

Fe(II) NM NM <0.002 NM <0.002 NM 0.004

Al <0.02 0.023 <0.02 0.033 <0.02 <0.02 <0.02

Mn <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 0.112

Cu <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01

Zn 0.063 0.063 <0.02 <0.02 <0.02 <0.02 <0.02

Pb <0.05 <0.05 <0.05 <0.05 <0.05 <0.05 <0.05

Cd 0.00032 0.00027 <0.00002 <0.00002 <0.00002 <0.00002 0.00006

Ni <0.0004 <0.0004 <0.0004 <0.0004 <0.0004 <0.0004 <0.0004

Ag <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001

Ba 0.0043 0.0043 0.0027 0.0031 0.0036 0.0040 0.010

Sr 0.049 0.048 0.046 0.055 0.141 0.164 0.043

B <0.005 <0.005 <0.005 <0.005 0.0065 <0.005 <0.005

Hardness (mg/L CaCO3) 19.9 NC 25.5 NC 46.3 NC 24.3

Sum cations (meq/L) 0.47 NC 0.56 NC 0.98 NC 0.54

Sum anions (meq/L) 0.48 NC 0.61 NC 1.03 NC 0.59

C.I. (%) –1.16 NC –4.77 NC –2.44 NC –4.46
Appendix 3 101

Appendix 3. Concentrations of major ions and selected metals.—Continued

[°C, degrees Celsius; mS/cm, microsiemens per centimeter; meq/L, milliequivalents per liter; mg/L, milligrams per liter; C.I., charge imbalance; DO, dissolved 

oxygen; EB, equipment blank; Eh, redox potential; FA, filtered, acidified; Fe(II), ferrous iron; FU, filtered, unacidified; NC, not computed; NM, not measured; 

–R, (appended to sample name), replicate sample; RA, unfiltered, acidified; SC, specific conductance; T, total; V, volts]

Property and 

constituent

Sample

EC–S5

–01

EC–S7

–01

EC–S7

–01

EC–S8A

–01

EC-S8A

–01

EC–S8A

–03

EC–S8A

–03

Property

Date 8/15/2006 8/16/2006 10/9/2006

pH 7.22 7.13 6.56

SC (mS/cm) 72 180 152

Temperature (°C) 5.2 3.4 3.5

DO (mg/L) 6.81 8.56 7.68

Eh (V) 0.484 0.452 NM

Treatment RA FA/FU RA FA/FU RA FA/FU RA

Constituent (mg/L)

Alkalinity as HCO3

– NM 34.8 NM 49.8 NM 45.9 NM

F NM 0.03 NM 0.08 NM 0.09 NM

Cl NM 0.03 NM 0.11 NM 0.47 NM

NO3 NM <0.05 NM 0.29 NM 0.32 NM

SO4 NM 7.67 NM 46.7 NM 36.1 NM

Ca 9.14 11.1 11.5 28.9 30.0 23.7 24.6

Mg 0.64 0.67 0.67 1.41 1.51 1.18 1.20

Na 0.94 1.26 1.22 1.90 1.93 1.71 1.67

SiO2 7.7 7.6 7.9 9.3 11.1 8.8 9.2

K 0.67 0.15 0.15 0.42 0.53 0.34 0.39

Fe(T) 0.248 0.003 <0.02 <0.002 0.477 0.012 <0.02

Fe(II) NM <0.002 NM <0.002 NM <0.002 NM

Al 0.270 <0.02 <0.02 <0.02 0.507 <0.02 0.025

Mn 0.157 <0.01 <0.01 <0.01 0.042 <0.01 <0.01

Cu <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01

Zn 0.021 <0.02 <0.02 <0.02 <0.02 <0.02 <0.02

Pb <0.05 <0.05 <0.05 <0.05 <0.05 <0.05 <0.05

Cd 0.00010 <0.00002 <0.00002 <0.00002 0.00002 <0.00002 <0.00002

Ni 0.0004 <0.0004 <0.0004 <0.0004 <0.0004 <0.0004 <0.0004

Ag <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001

Ba 0.014 0.0051 0.0054 0.0055 0.010 0.0046 0.0053

Sr 0.051 0.054 0.061 0.143 0.165 0.116 0.120

B <0.005 <0.005 <0.005 <0.005 <0.005 <0.005 <0.005

Hardness (mg/L CaCO3) NC 30.5 NC 78.1 NC 64.2 NC

Sum cations (meq/L) NC 0.66 NC 1.58 NC 1.32 NC

Sum anions (meq/L) NC 0.73 NC 1.73 NC 1.48 NC

C.I. (%) NC –4.61 NC –4.39 NC –5.76 NC
102 Hydrogeochemical Investigation of the Standard Mine Vicinity, Upper Elk Creek Basin, Colorado

Appendix 3. Concentrations of major ions and selected metals.—Continued

[°C, degrees Celsius; mS/cm, microsiemens per centimeter; meq/L, milliequivalents per liter; mg/L, milligrams per liter; C.I., charge imbalance; DO, dissolved 

oxygen; EB, equipment blank; Eh, redox potential; FA, filtered, acidified; Fe(II), ferrous iron; FU, filtered, unacidified; NC, not computed; NM, not measured; 

–R (appended to sample name), replicate sample; RA, unfiltered, acidified; SC, specific conductance; T, total; V, volts]

Property and

constituent

Sample

EC–S8A

–04

EC–S8A

–04

EC–S8B

–01

EC–S8B

–01

EC–S9

–01

EC–S9

–01

EC–S10

–01

Property

Date 6/17/2007 8/16/2006 8/16/2006 8/16/2006

pH 7.31 7.35 6.38 4.71

SC (mS/cm) 157 180 109 187

Temperature (°C) 2.9 3.6 5.5 11.9

DO (mg/L) 9.42 8.32 6.36 2.82

Eh (V) NM 0.450 0.474 0.571

Treatment FA/FU RA FA/FU RA FA/FU RA FA/FU

Constituent (mg/L)

Alkalinity as HCO3

– 41.2 NM 48.6 NM 19.2 NM <1.0

F 0.05 NM 0.08 NM 0.06 NM 0.18

Cl 0.09 NM 0.15 NM 0.11 NM 0.21

NO3 0.12 NM 0.22 NM <0.05 NM 0.12

SO4 37.4 NM 45.4 NM 34.2 NM 73.0

Ca 25.9 26.1 28.8 29.6 16.1 15.5 17.3

Mg 1.23 1.27 1.38 1.45 1.18 1.20 3.58

Na 1.97 1.99 1.87 1.85 1.23 1.17 2.21

SiO2 7.7 7.9 9.4 10.2 7.6 7.9 15.8

K 0.39 0.37 0.67 0.90 0.39 0.47 1.03

Fe(T) <0.02 0.132 0.002 0.185 0.014 0.141 0.017

Fe(II) NM NM 0.002 NM 0.010 NM 0.011

Al 0.072 0.095 <0.02 0.213 <0.02 0.073 1.20

Mn <0.01 0.013 <0.01 0.026 <0.01 0.019 0.816

Cu <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 0.038

Zn <0.02 <0.02 <0.02 <0.02 0.195 0.216 3.33

Pb <0.05 <0.05 <0.05 <0.05 <0.05 <0.05 0.232

Cd <0.00002 <0.00002 <0.00002 0.00002 0.00038 0.00043 0.0262

Ni <0.0004 <0.0004 <0.0004 <0.0004 0.0005 0.0005 0.0043

Ag <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001

Ba 0.0048 0.0054 0.0052 0.0075 0.0038 0.0048 0.037

Sr 0.122 0.125 0.143 0.163 0.094 0.095 0.118

B 0.0089 <0.005 0.0055 <0.005 <0.005 <0.005 0.0066

Hardness (mg/L CaCO3) 69.9 NC 77.8 NC 45.2 NC 59.6

Sum cations (meq/L) 1.44 NC 1.58 NC 0.94 NC 1.43

Sum anions (meq/L) 1.41 NC 1.68 NC 1.00 NC 1.40

C.I. (%) 1.18 NC –3.10 NC –3.10 NC 1.20
Appendix 3 103

Appendix 3. Concentrations of major ions and selected metals.—Continued

[°C, degrees Celsius; mS/cm, microsiemens per centimeter; meq/L, milliequivalents per liter; mg/L, milligrams per liter; C.I., charge imbalance; DO, dissolved 

oxygen; EB, equipment blank; Eh, redox potential; FA, filtered, acidified; Fe(II), ferrous iron; FU, filtered, unacidified; NC, not computed; NM, not measured; 

–R (appended to sample name), replicate sample; RA, unfiltered, acidified; SC, specific conductance; T, total; V, volts]

Property and

constituent

Sample

EC–S10

–01

EC–S11

–01

EC–S11

–01

EC–S11–01

–R

EC–S11–01

–R

EC–S12

–01

EC–S12

–01

Property

Date 8/17/2006 8/17/2006 8/17/2006

pH 6.20 6.20 7.25

SC (mS/cm) 57 57 230

Temperature (°C) 13.4 13.4 3.5

DO (mg/L) 6.67 6.67 8.85

Eh (V) 0.425 0.425 0.475

Treatment RA FA/FU RA FA/FU RA FA/FU RA

Constituent (mg/L)

Alkalinity as HCO3

– NM 9.4 NM 9.4 NM 60.0 NM

F NM 0.04 NM 0.04 NM 0.10 NM

Cl NM 0.20 NM 0.18 NM 0.17 NM

NO3 NM 0.23 NM 0.26 NM 0.54 NM

SO4 NM 17.8 NM 17.7 NM 65.6 NM

Ca 17.2 7.15 6.97 7.06 6.96 38.4 39.4

Mg 3.74 0.59 0.60 0.60 0.60 1.71 1.76

Na 2.24 0.83 0.83 0.84 0.82 2.25 2.23

SiO2 18.5 5.7 5.9 5.8 6.0 9.1 9.6

K 1.35 0.34 0.34 0.33 0.30 0.50 0.54

Fe(T) 0.691 0.020 0.032 0.021 0.030 0.004 0.037

Fe(II) NM 0.010 NM 0.003 NM <0.002 NM

Al 2.23 <0.02 <0.02 <0.02 <0.02 <0.02 0.037

Mn 0.905 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01

Cu 0.066 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01

Zn 3.63 0.882 0.944 0.889 0.956 <0.02 <0.02

Pb 0.318 0.102 0.110 0.097 0.109 <0.05 <0.05

Cd 0.0262 0.00553 0.00530 0.00548 0.00545 <0.00002 <0.00002

Ni 0.0046 <0.0004 <0.0004 <0.0004 <0.0004 <0.0004 <0.0004

Ag 0.0120 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001

Ba 0.043 0.0087 0.0096 0.0089 0.0097 0.0059 0.0068

Sr 0.132 0.039 0.044 0.038 0.044 0.171 0.193

B <0.005 <0.005 <0.005 <0.005 <0.005 <0.005 <0.005

Hardness (mg/L CaCO3) NC 20.3 NC 20.2 NC 103 NC

Sum cations (meq/L) NC 0.47 NC 0.47 NC 2.05 NC

Sum anions (meq/L) NC 0.52 NC 0.52 NC 2.25 NC

C.I. (%) NC –5.61 NC –5.77 NC –4.57 NC
104 Hydrogeochemical Investigation of the Standard Mine Vicinity, Upper Elk Creek Basin, Colorado

Appendix 3. Concentrations of major ions and selected metals.—Continued

[°C, degrees Celsius; mS/cm, microsiemens per centimeter; meq/L, milliequivalents per liter; mg/L, milligrams per liter; C.I., charge imbalance; DO, dissolved 

oxygen; EB, equipment blank; Eh, redox potential; FA, filtered, acidified; Fe(II), ferrous iron; FU, filtered, unacidified; NC, not computed; NM, not measured; 

–R (appended to sample name), replicate sample; RA, unfiltered, acidified; SC, specific conductance; T, total; V, volts]

Property and 

constituent

Sample

EC–MUSTD1

–01

EC–MUSTD1

–01

RW–S1

–01

RW–S1

–01

RW–S2

–01

RW–S2

–01

RW–S2–01

–R

Property

Date 7/18/2006 8/18/2006 8/18/2006 8/18/2006

pH 2.97 6.65 3.68 3.68

SC (mS/cm) 773 75 249 249

Temperature (°C) 10.0 2.8 5.40 5.40

DO (mg/L) 5.60 9.43 0.54 0.54

Eh (V) NM 0.476 0.547 0.547

Treatment FA/FU RA FA/FU RA FA/FU RA FA/FU

Constituent (mg/L)

Alkalinity as HCO3

– NM NM 11.2 NM NM NM NM

F 0.05 NM 0.06 NM 0.86 NM 0.88

Cl 0.08 NM 0.07 NM 0.30 NM 0.18

NO3 0.43 NM 0.86 NM <0.05 NM <0.05

SO4 183 NM 25.4 NM 81.5 NM 79.5

Ca 18.7 19.9 10.2 10.7 4.09 4.20 4.25

Mg 3.85 4.05 0.96 0.96 1.68 1.72 1.74

Na 1.66 1.68 0.94 0.92 0.65 0.59 0.69

SiO2 16.8 17.8 5.9 6.1 15.3 15.7 15.9

K 0.59 0.73 0.35 0.35 1.17 1.27 1.20

Fe(T) 2.30 2.58 0.002 <0.02 17.1 22.0 18.4

Fe(II) 0.122 NM <0.002 NM 17.0 NM 17.9

Al 4.04 4.45 <0.02 0.048 2.85 3.07 2.97

Mn 5.42 6.18 <0.01 0.014 1.48 1.63 1.54

Cu 1.08 1.19 <0.01 <0.01 <0.01 <0.01 <0.01

Zn 24.0 27.0 0.148 0.160 5.84 6.19 6.10

Pb 0.622 0.644 <0.05 <0.05 1.88 1.92 1.94

Cd 0.190 0.181 0.00070 0.00068 0.0540 0.0542 0.0553

Ni 0.0154 0.0150 <0.0004 <0.0004 0.0035 0.0036 0.0036

Ag 0.0012 0.0011 <0.001 <0.001 <0.001 <0.001 <0.001

Ba 0.016 0.018 0.0073 0.0080 0.016 0.018 0.017

Sr 0.148 0.171 0.057 0.067 0.016 0.018 0.017

B <0.005 <0.005 <0.005 <0.005 <0.005 <0.005 <0.005

Hardness (mg/L CaCO3) 72.8 NC 29.5 NC 50.3 NC 52.6

Sum cations (meq/L) 3.51 NC 0.63 NC 1.62 NC 1.69

Sum anions (meq/L) 3.21 NC 0.71 NC 1.55 NC 1.50

C.I. (%) 4.47 NC –6.52 NC 1.92 NC 5.97
Appendix 3 105

Appendix 3. Concentrations of major ions and selected metals.—Continued

[°C, degrees Celsius; mS/cm, microsiemens per centimeter; meq/L, milliequivalents per liter; mg/L, milligrams per liter; C.I., charge imbalance; DO, dissolved 

oxygen; EB, equipment blank; Eh, redox potential; FA, filtered, acidified; Fe(II), ferrous iron; FU, filtered, unacidified; NC, not computed; NM, not measured; 

–R (appended to sample name), replicate sample; RA, unfiltered, acidified; SC, specific conductance; T, total; V, volts]

Property and

constituent

Sample

RW–S2–01

–R

EC–P4

–01

EC–P4

–01

EC–P5

–01

EC–P5

–01

EC–MSTD1

–01

EC–MSTD1

–01

Property

Date 8/16/2006 8/17/2006 7/18/2006

pH 5.60 5.78 5.62

SC (mS/cm) 47 78 479

Temperature (°C) 13.4 9.2 4.5

DO (mg/L) 6.70 6.90 6.55

Eh (V) 0.491 0.461 NM

Treatment RA FA/FU RA FA/FU RA FA/FU RA

Constituent (mg/L)

Alkalinity as HCO3

– NM 2.0 NM 4.6 NM 6.7 NM

F NM 0.04 NM 0.09 NM 0.30 NM

Cl NM 0.09 NM 0.12 NM 0.14 NM

NO3 NM <0.05 NM <0.05 NM 1.8 NM

SO4 NM 16.2 NM 27.5 NM 212 NM

Ca 4.34 4.38 4.41 7.91 7.98 55.8 60.9

Mg 1.77 0.84 0.85 1.56 1.57 6.34 6.80

Na 0.61 0.58 0.58 1.27 1.27 2.59 2.69

SiO2 16.3 2.7 3.0 7.9 8.2 10.9 12.0

K 1.34 0.62 0.73 0.48 0.48 0.87 1.01

Fe(T) 22.0 0.188 2.09 0.055 0.123 0.570 1.70

Fe(II) NM 0.181 NM 0.034 NM 0.303 NM

Al 3.14 <0.02 0.065 0.048 0.068 0.390 0.977

Mn 1.68 0.086 0.104 0.328 0.348 9.00 10.0

Cu <0.01 <0.01 0.073 <0.01 <0.01 0.419 0.508

Zn 6.43 0.174 0.211 0.777 0.857 24.0 27.0

Pb 1.99 0.410 1.05 <0.05 <0.05 0.859 1.16

Cd 0.0526 0.00071 0.00090 0.00482 0.00514 0.154 0.154

Ni 0.0034 0.0007 0.0009 0.0010 0.0011 0.0155 0.0146

Ag <0.001 <0.001 0.0048 <0.001 <0.001 <0.001 <0.001

Ba 0.018 0.043 0.047 0.041 0.046 0.013 0.015

Sr 0.019 0.033 0.033 0.058 0.069 0.448 0.530

B <0.005 <0.005 <0.005 <0.005 <0.005 0.012 0.011

Hardness (mg/L CaCO3) NC 14.9 NC 26.9 NC 183 NC

Sum cations (meq/L) NC 0.34 NC 0.62 NC 3.99 NC

Sum anions (meq/L) NC 0.37 NC 0.63 NC 3.96 NC

C.I. (%) NC –3.22 NC –1.55 NC 0.32 NC
106 Hydrogeochemical Investigation of the Standard Mine Vicinity, Upper Elk Creek Basin, Colorado

Appendix 3. Concentrations of major ions and selected metals.—Continued

[°C, degrees Celsius; mS/cm, microsiemens per centimeter; meq/L, milliequivalents per liter; mg/L, milligrams per liter; C.I., charge imbalance; DO, dissolved 

oxygen; EB, equipment blank; Eh, redox potential; FA, filtered, acidified; Fe(II), ferrous iron; FU, filtered, unacidified; NC, not computed; NM, not measured; 

–R (appended to sample name), replicate sample; RA, unfiltered, acidified; SC, specific conductance; T, total; V, volts]

Property and

constituent

Sample

EC–MSTD1

–02

EC–MSTD1

–02

EC–MSTD1

–02R

EC–MSTD1

–02R

EC–MSTD1

–03

EC–MSTD1

–03

EC–MSTD1

–03R

Property

Date 8/16/2006 8/16/2006 10/9/2006 10/9/2006

pH 6.20 6.20 5.58 5.58

SC (mS/cm) 518 518 452 452

Temperature (°C) 4.5 4.5 4.5 4.5

DO (mg/L) 8.23 8.23 6.31 6.31

Eh (V) 0.422 0.422 NM NM

Treatment FA/FU RA FA/FU RA FA/FU RA FA/FU

Constituent (mg/L)

Alkalinity as HCO3

– 12.0 NM 11.7 NM 3.5 NM 3.4

F 0.35 NM 0.35 NM 0.34 NM 0.37

Cl 0.15 NM 0.15 NM 0.12 NM 0.17

NO3 0.26 NM 0.28 NM 0.62 NM 0.66

SO4 232 NM 233 NM 235 NM 232

Ca 60.4 63.0 60.6 65.5 58.5 60.2 55.9

Mg 6.91 7.10 6.94 7.36 6.89 6.54 6.49

Na 2.74 2.77 2.76 2.80 2.63 2.51 2.54

SiO2 10.6 11.4 10.6 11.6 12.0 12.2 11.5

K 0.91 1.00 0.91 1.04 0.88 1.00 0.85

Fe(T) 0.510 1.68 0.518 1.73 1.79 3.89 1.70

Fe(II) 0.510 NM 0.499 NM 1.58 NM 1.51

Al 0.221 0.849 0.236 0.846 0.489 1.30 0.485

Mn 10.0 11.0 10.0 12.0 9.79 10.0 9.48

Cu 0.226 0.304 0.227 0.309 0.375 0.443 0.368

Zn 24.0 27.0 24.0 27.0 25.0 27.0 24.0

Pb 0.661 1.02 0.672 1.03 1.09 1.54 1.04

Cd 0.151 0.148 0.156 0.147 0.155 0.150 0.156

Ni 0.0162 0.0154 0.0167 0.0159 0.0184 0.0173 0.0184

Ag <0.001 <0.001 <0.001 <0.001 0.0012 0.0013 0.0012

Ba 0.014 0.015 0.014 0.015 0.014 0.015 0.014

Sr 0.487 0.552 0.489 0.572 0.468 0.532 0.448

B 0.013 0.011 0.011 0.011 0.012 0.0082 0.0098

Hardness (mg/L CaCO3) 199 NC 200 NC 196 NC 187

Sum cations (meq/L) 4.21 NC 4.22 NC 4.21 NC 4.02

Sum anions (meq/L) 4.37 NC 4.39 NC 4.29 NC 4.26

C.I. (%) –1.87 NC –1.88 NC –1.00 NC –2.87
Appendix 3 107

Appendix 3. Concentrations of major ions and selected metals.—Continued

[°C, degrees Celsius; mS/cm, microsiemens per centimeter; meq/L, milliequivalents per liter; mg/L, milligrams per liter; C.I., charge imbalance; DO, dissolved 

oxygen; EB, equipment blank; Eh, redox potential; FA, filtered, acidified; Fe(II), ferrous iron; FU, filtered, unacidified; NC, not computed; NM, not measured; 

–R (appended to sample name), replicate sample; RA, unfiltered, acidified; SC, specific conductance; T, total; V, volts]

Property and

constituent

Sample

EC–MSTD1

–03R

EC–MSTD1

–04

EC–MSTD1

–04

EC–MSTD1

–05

EC–MSTD1

–05

EC–MSTD1

–06

EC–MSTD1

–06

Property

Date 2/25/2007 4/14/2007 5/5/2007

pH 6.60 6.68 4.03

SC (mS/cm) 613 572 485

Temperature (°C) 0.5 0.5 0.5

DO (mg/L) NM NM NM

Eh (V) NM NM NM

Treatment RA FA/FU RA FA/FU RA FA/FU RA

Constituent (mg/L)

Alkalinity as HCO3

– NM 25.2 NM 22.7 NM NM NM

F NM 0.49 NM 0.44 NM 0.13 NM

Cl NM 0.22 NM 0.19 NM 0.19 NM

NO3 NM <0.05 NM <0.05 NM 0.50 NM

SO4 NM 280 NM 267 NM 222 NM

Ca 61.0 83.2 84.8 79.0 80.6 53.3 50.3

Mg 6.67 9.01 9.24 8.71 8.93 6.26 5.48

Na 2.55 3.56 3.80 3.41 3.59 2.31 2.60

SiO2 12.4 8.4 8.8 9.0 9.5 10.0 9.4

K 1.07 1.10 1.14 1.04 1.08 0.86 1.91

Fe(T) 3.65 0.277 1.14 0.280 1.55 1.90 4.79

Fe(II) NM 0.227 NM 0.227 NM 1.54 NM

Al 1.32 <0.02 0.283 <0.02 0.622 1.63 1.63

Mn 11.0 11.0 11.0 10.0 11.0 7.96 7.35

Cu 0.435 0.080 0.131 0.113 0.203 0.590 0.560

Zn 27.0 25.0 26.0 25.0 26.0 23.0 22.0

Pb 1.58 0.067 0.321 0.205 0.678 1.78 1.67

Cd 0.149 0.132 0.132 0.138 0.134 0.141 0.133

Ni 0.0172 0.0144 0.0149 0.0165 0.0166 0.0182 0.0189

Ag 0.0014 <0.001 <0.001 <0.001 <0.001 0.0015 <0.001

Ba 0.016 0.014 0.015 0.013 0.014 0.015 0.021

Sr 0.538 0.650 0.672 0.617 0.638 0.407 0.395

B 0.0093 0.011 0.0095 0.0093 0.0092 0.0069 <0.005

Hardness (mg/L CaCO3) NC 266 NC 252 NC 177 NC

Sum cations (meq/L) NC 5.37 NC 5.15 NC 4.05 NC

Sum anions (meq/L) NC 5.37 NC 5.12 NC 3.99 NC

C.I. (%) NC –0.02 NC 0.34 NC 0.79 NC
108 Hydrogeochemical Investigation of the Standard Mine Vicinity, Upper Elk Creek Basin, Colorado

Appendix 3. Concentrations of major ions and selected metals.—Continued

[°C, degrees Celsius; mS/cm, microsiemens per centimeter; meq/L, milliequivalents per liter; mg/L, milligrams per liter; C.I., charge imbalance; DO, dissolved 

oxygen; EB, equipment blank; Eh, redox potential; FA, filtered, acidified; Fe(II), ferrous iron; FU, filtered, unacidified; NC, not computed; NM, not measured; 

–R (appended to sample name), replicate sample; RA, unfiltered, acidified; SC, specific conductance; T, total; V, volts]

Property and

constituent

Sample

EC–MSTD1

–07

EC–MSTD1

–07

EC–MSTD1

–08

EC–MSTD1

–08

EC–MSTD1

–09

EC–MSTD1

–09

EC–MSTDL31

–01

Property

Date 5/15/2007 6/3/2007 6/17/2007 8/17/2006

pH 3.56 3.42 3.84 4.29

SC (mS/cm) 488 453 442 178

Temperature (°C) 3.1 3.7 4.1 5.1

DO (mg/L) NM NM 8.40 8.20

Eh (V) NM NM NM 0.625

Treatment FA/FU RA FA/FU RA FA/FU RA FA/FU

Constituent (mg/L)

Alkalinity as HCO3

– NM NM NM NM NM NM NM

F 0.14 NM 0.11 NM 0.12 NM 0.06

Cl 0.19 NM 0.17 NM 0.24 NM 0.15

NO3 0.30 NM 0.15 NM 0.15 NM 0.51

SO4 212 NM 169 NM 166 NM 61.0

Ca 52.6 52.8 39.2 38.0 38.7 38.8 11.1

Mg 6.12 6.20 4.23 4.11 4.08 4.01 2.65

Na 2.26 2.34 1.97 1.89 1.86 1.92 1.20

SiO2 9.1 9.2 9.3 8.9 8.8 8.6 11.4

K 0.87 0.90 0.77 0.75 0.70 0.74 0.61

Fe(T) 0.641 2.68 2.16 3.25 1.26 2.15 0.042

Fe(II) 0.535 NM 0.502 NM 0.366 NM 0.017

Al 1.07 1.24 1.09 1.05 0.928 0.900 1.24

Mn 8.92 9.19 6.31 6.20 5.82 5.77 1.70

Cu 0.439 0.459 0.869 0.842 0.630 0.624 0.365

Zn 24.0 25.0 21.0 21.0 18.0 18.0 5.58

Pb 1.23 1.32 1.43 1.36 1.40 1.39 1.98

Cd 0.145 0.139 0.132 0.128 0.121 0.115 0.0348

Ni 0.0166 0.0164 0.0109 0.0113 0.0108 0.0105 0.0053

Ag 0.0010 0.0012 <0.001 0.0011 <0.001 0.0012 <0.001

Ba 0.014 0.015 0.016 0.015 0.014 0.014 0.023

Sr 0.398 0.404 0.304 0.301 0.303 0.308 0.074

B 0.0071 <0.005 0.0056 <0.005 0.0069 0.0055 <0.005

Hardness (mg/L CaCO3) 174 NC 128 NC 125 NC 41.8

Sum cations (meq/L) 4.19 NC 3.51 NC 3.07 NC 1.19

Sum anions (meq/L) 3.80 NC 3.05 NC 3.05 NC 1.18

C.I. (%) 4.85 NC 6.93 NC 0.21 NC 0.58
Appendix 3 109

Appendix 3. Concentrations of major ions and selected metals.—Continued

[°C, degrees Celsius; mS/cm, microsiemens per centimeter; meq/L, milliequivalents per liter; mg/L, milligrams per liter; C.I., charge imbalance; DO, dissolved 

oxygen; EB, equipment blank; Eh, redox potential; FA, filtered, acidified; Fe(II), ferrous iron; FU, filtered, unacidified; NC, not computed; NM, not measured; 

–R (appended to sample name), replicate sample; RA, unfiltered, acidified; SC, specific conductance; T, total; V, volts]

Property and

constituent

Sample

EC–MSTDL31

–01

EC–MSTDL32

–01

EC–MSTDL32

–01

EC–MSTDL33

–01

EC–MSTDL33

–01

EC–MSTDL34

–01

Property

Date 8/17/2006 8/17/2006 8/17/2006

pH 3.26 6.95 6.95

SC (mS/cm) 424 153 188

Temperature (°C) 4.7 4.4 4.2

DO (mg/L) 8.54 9.21 8.74

Eh (V) 0.675 0.535 0.567

Treatment RA FA/FU RA FA/FU RA FA/FU

Constituent (mg/L)

Alkalinity as HCO3

– NM NM NM 28.7 NM 31.4

F NM 0.07 NM 0.15 NM 0.26

Cl NM 0.11 NM 0.11 NM 0.10

NO3 NM 0.29 NM <0.05 NM <0.05

SO4 NM 111 NM 31.7 NM 58.6

Ca 11.5 19.1 20.0 20.2 20.5 27.2

Mg 2.69 1.46 1.52 1.18 1.21 2.21

Na 1.14 1.51 1.49 1.58 1.54 1.78

SiO2 11.7 10.2 10.8 9.9 10.2 8.9

K 0.68 0.45 0.52 0.46 0.48 0.62

Fe(T) 0.156 3.69 7.10 0.017 0.428 0.018

Fe(II) NM 1.93 NM 0.005 NM 0.007

Al 1.36 0.804 0.880 <0.02 <0.02 <0.02

Mn 1.83 1.02 1.15 0.013 0.020 0.243

Cu 0.385 1.73 1.88 0.110 0.162 0.054

Zn 5.88 7.55 8.44 1.06 1.24 2.02

Pb 2.03 2.35 2.52 0.103 0.303 <0.05

Cd 0.0362 0.112 0.106 0.00727 0.00775 0.0218

Ni 0.0052 0.0052 0.0049 0.0008 0.0008 0.0026

Ag 0.0011 <0.001 0.0022 <0.001 <0.001 <0.001

Ba 0.025 0.010 0.011 0.0062 0.0071 0.016

Sr 0.082 0.140 0.160 0.144 0.156 0.241

B <0.005 0.0054 <0.005 0.0056 <0.005 0.0067

Hardness (mg/L CaCO3) NC 59.2 NC 55.5 NC 77.8

Sum cations (meq/L) NC 2.12 NC 1.18 NC 1.62

Sum anions (meq/L) NC 2.09 NC 1.10 NC 1.66

C.I. (%) NC 0.72 NC 3.68 NC –1.24
110 Hydrogeochemical Investigation of the Standard Mine Vicinity, Upper Elk Creek Basin, Colorado

Appendix 3. Concentrations of major ions and selected metals.—Continued

[°C, degrees Celsius; mS/cm, microsiemens per centimeter; meq/L, milliequivalents per liter; mg/L, milligrams per liter; C.I., charge imbalance; DO, dissolved 

oxygen; EB, equipment blank; Eh, redox potential; FA, filtered, acidified; Fe(II), ferrous iron; FU, filtered, unacidified; NC, not computed; NM, not measured; 

–R (appended to sample name), replicate sample; RA, unfiltered, acidified; SC, specific conductance; T, total; V, volts]

Property and

constituent

Sample

EC–MSTDL34

–01

EC–MSTDL35

–01

EC–MSTDL35

–01

EC–M11600

–01

EC–M11600

–01

EC–M116001

–01

Property

Date 8/17/2006 8/15/2006 8/17/2006

pH 6.77 6.66 6.70

SC (mS/cm) 265 215 302

Temperature (°C) 4.2 3.6 3.8

DO (mg/L) 8.78 8.55 3.62

Eh (V) 0.554 0.384 0.278

Treatment RA FA/FU RA FA/FU RA FA/FU

Constituent (mg/L)

Alkalinity as HCO3

– NM 33.7 NM 10.8 NM 46.4

F NM 0.29 NM 0.37 NM 0.53

Cl NM 0.24 NM 0.25 NM 0.21

NO3 NM <0.05 NM <0.05 NM <0.05

SO4 NM 92.1 NM 81.1 NM 99.1

Ca 27.8 38.4 39.8 25.5 26.3 33.5

Mg 2.26 3.25 3.37 3.49 3.59 7.16

Na 1.75 2.06 2.12 2.75 2.74 2.99

SiO2 10.3 10.1 10.6 13.4 14.7 8.4

K 0.77 0.80 0.95 0.72 0.90 0.66

Fe(T) 1.21 0.022 0.038 0.557 1.68 5.44

Fe(II) NM 0.006 NM 0.529 NM 5.28

Al 0.622 <0.02 <0.02 <0.02 0.254 <0.02

Mn 0.280 0.207 0.237 2.31 2.57 4.40

Cu 0.201 0.435 0.491 <0.01 <0.01 <0.01

Zn 2.29 2.80 3.14 2.95 3.31 2.26

Pb 0.393 0.152 0.159 <0.05 0.227 <0.05

Cd 0.0231 0.0221 0.0209 0.0245 0.0241 0.00008

Ni 0.0026 0.0073 0.0068 0.0026 0.0024 0.0021

Ag <0.001 <0.001 <0.001 <0.001 <0.001 <0.001

Ba 0.020 0.013 0.015 0.015 0.019 0.013

Sr 0.270 0.398 0.449 0.178 0.197 0.210

B <0.005 0.012 0.012 0.005 <0.005 0.005

Hardness (mg/L CaCO3) NC 110 NC 83.4 NC 131

Sum cations (meq/L) NC 2.23 NC 1.77 NC 2.62

Sum anions (meq/L) NC 2.31 NC 1.77 NC 2.65

C.I. (%) NC –1.84 NC 0.11 NC –0.46
Appendix 3 111

Appendix 3. Concentrations of major ions and selected metals.—Continued

[°C, degrees Celsius; mS/cm, microsiemens per centimeter; meq/L, milliequivalents per liter; mg/L, milligrams per liter; C.I., charge imbalance; DO, dissolved 

oxygen; EB, equipment blank; Eh, redox potential; FA, filtered, acidified; Fe(II), ferrous iron; FU, filtered, unacidified; NC, not computed; NM, not measured; 

–R (appended to sample name), replicate sample; RA, unfiltered, acidified; SC, specific conductance; T, total; V, volts]

Property and

constituent

Sample

EC–M116001

–01

EC–M116002

–01

EC–M116002

–01

EC–M11400B

–01

EC–M11400B

–01

EC–M11400B

–01R

Property

Date 8/17/2006 8/15/2006 8/15/2006

pH 7.20 6.28 6.28

SC (mS/cm) 241 88 88

Temperature (°C) 3.6 7.5 7.5

DO (mg/L) NM 5.88 5.88

Eh (V) 0.354 0.462 0.462

Treatment RA FA/FU RA FA/FU RA FA/FU

Constituent (mg/L)

Alkalinity as HCO3

– NM 60.2 NM 17.2 NM 17.3

F NM 0.86 NM 0.06 NM 0.04

Cl NM 0.24 NM 0.26 NM 0.20

NO3 NM <0.05 NM 1.9 NM 2.1

SO4 NM 64.5 NM 24.4 NM 24.6

Ca 35.3 35.4 38.5 10.3 10.6 10.3

Mg 7.55 2.79 2.97 0.94 0.95 0.93

Na 3.06 4.03 4.25 1.03 1.00 1.02

SiO2 8.8 11.8 12.9 7.0 7.4 7.0

K 0.72 0.65 0.70 0.34 0.37 0.35

Fe(T) 6.45 0.318 0.675 0.045 2.35 0.042

Fe(II) NM 0.272 NM 0.040 NM 0.037

Al <0.02 <0.02 <0.02 0.037 0.201 0.035

Mn 5.01 1.41 1.62 0.359 0.432 0.356

Cu <0.01 <0.01 <0.01 0.087 0.126 0.089

Zn 2.50 0.536 0.626 3.03 3.30 3.04

Pb <0.05 <0.05 <0.05 0.525 1.24 0.527

Cd 0.00011 0.00346 0.00350 0.0171 0.0167 0.0168

Ni 0.0020 0.0004 <0.0004 0.0007 0.0006 0.0007

Ag <0.001 <0.001 <0.001 <0.001 <0.001 <0.001

Ba 0.014 0.010 0.012 0.013 0.015 0.013

Sr 0.242 0.227 0.269 0.069 0.079 0.069

B <0.005 0.0070 0.0068 <0.005 <0.005 <0.005

Hardness (mg/L CaCO3) NC 103 NC 30.4 NC 30.3

Sum cations (meq/L) NC 2.15 NC 0.74 NC 0.74

Sum anions (meq/L) NC 2.26 NC 0.81 NC 0.81

C.I. (%) NC –2.51 NC –4.25 NC –4.72
112 Hydrogeochemical Investigation of the Standard Mine Vicinity, Upper Elk Creek Basin, Colorado

Appendix 3. Concentrations of major ions and selected metals.—Continued

[°C, degrees Celsius; mS/cm, microsiemens per centimeter; meq/L, milliequivalents per liter; mg/L, milligrams per liter; C.I., charge imbalance; DO, dissolved 

oxygen; EB, equipment blank; Eh, redox potential; FA, filtered, acidified; Fe(II), ferrous iron; FU, filtered, unacidified; NC, not computed; NM, not measured; 

–R (appended to sample name), replicate sample; RA, unfiltered, acidified; SC, specific conductance; T, total; V, volts]

Property and

constituent

Sample

EC–M11400B

–01R

EB–01 EB–01 EB–02 EB–02 EB–03 EB–03

Property

Date 8/15/2006 8/16/2006 8/18/2006

pH NM NM NM

SC (mS/cm) NM NM NM

Temperature (°C) NM NM NM

DO (mg/L) NM NM NM

Eh (V) NM NM NM

Treatment RA FA/FU RA FA/FU RA FA/FU RA

Constituent (mg/L)

Alkalinity as HCO3

– NM 2.2 NM 2.0 NM 2.0 NM

F NM <0.03 NM <0.03 NM <0.03 NM

Cl NM <0.03 NM <0.03 NM <0.03 NM

NO3 NM <0.05 NM <0.05 NM <0.05 NM

SO4 NM <0.1 NM <0.1 NM <0.1 NM

Ca 10.5 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1

Mg 0.91 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1

Na 0.98 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1

SiO2 7.0 <0.1 0.21 <0.1 0.18 <0.1 0.21

K 0.35 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1

Fe(T) 1.12 <0.002 <0.02 <0.002 <0.02 <0.002 <0.02

Fe(II) NM <0.002 NM <0.002 NM <0.002 NM

Al 0.113 <0.02 <0.02 <0.02 <0.02 <0.02 <0.02

Mn 0.395 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01

Cu 0.106 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01

Zn 3.21 <0.02 <0.02 <0.02 <0.02 <0.02 <0.02

Pb 0.909 <0.05 <0.05 <0.05 <0.05 <0.05 <0.05

Cd 0.0167 <0.00002 <0.00002 <0.00002 <0.00002 <0.00002 <0.00002

Ni 0.0007 <0.0004 <0.0004 <0.0004 <0.0004 <0.0004 <0.0004

Ag <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001

Ba 0.014 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001

Sr 0.079 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001

B <0.005 <0.005 <0.005 <0.005 <0.005 <0.005 <0.005

Hardness (mg/L CaCO3) NC NC NC NC NC NC NC

Sum cations (meq/L) NC NC NC NC NC NC NC

Sum anions (meq/L) NC NC NC NC NC NC NC

C.I. (%) NC NC NC NC NC NC NC
Appendix 3 113

Appendix 3. Concentrations of major ions and selected metals.—Continued

[°C, degrees Celsius; mS/cm, microsiemens per centimeter; meq/L, milliequivalents per liter; mg/L, milligrams per liter; C.I., charge imbalance; DO, dissolved 

oxygen; EB, equipment blank; Eh, redox potential; FA, filtered, acidified; Fe(II), ferrous iron; FU, filtered, unacidified; NC, not computed; NM, not measured; 

–R (appended to sample name), replicate sample; RA, unfiltered, acidified; SC, specific conductance; T, total; V, volts]

Property and

constituent

Sample

EB–04 EB–04 EB–05 EB–05

Property

Date 10/9/2006 6/20/2007

pH NM NM

SC (mS/cm) NM NM

Temperature (°C) NM NM

DO (mg/L) NM NM

Eh (V) NM NM

Treatment FA/FU RA FA/FU RA

Constituent (mg/L)

Alkalinity as HCO3

– 2.0 NM 2.2 NM

F <0.03 NM <0.05 NM

Cl <0.03 NM <0.05 NM

NO3 <0.05 NM <0.05 NM

SO4 <0.1 NM <0.05 NM

Ca <0.1 <0.1 <0.1 <0.1

Mg <0.1 <0.1 <0.1 <0.1

Na <0.1 <0.1 0.13 <0.1

SiO2 <0.1 <0.1 <0.1 <0.1

K <0.1 <0.1 <0.1 <0.1

Fe(T) 0.002 <0.02 <0.002 <0.02

Fe(II) <0.002 NM <0.002 NM

Al <0.02 <0.02 <0.02 <0.02

Mn <0.01 <0.01 <0.01 <0.01

Cu <0.01 <0.01 <0.01 <0.01

Zn <0.02 <0.02 <0.02 <0.02

Pb <0.05 <0.05 <0.05 <0.05

Cd <0.00002 <0.00002 <0.00002 <0.00002

Ni <0.0004 <0.0004 <0.0004 <0.0004

Ag <0.001 <0.001 <0.001 <0.001

Ba <0.001 <0.001 <0.001 <0.001

Sr <0.001 <0.001 <0.001 <0.001

B <0.005 <0.005 <0.005 <0.005

Hardness (mg/L CaCO3) NC NC NC NC

Sum cations (meq/L) NC NC NC NC

Sum anions (meq/L) NC NC NC NC

C.I. (%) NC NC NC NC

1

ICP–AES results shown. See appendix 4 for ICP–MS results.
114 
Appendix 4. Results of ICP–MS Analyses

 115
116 Hydrogeochemical Investigation of the Standard Mine Vicinity, Upper Elk Creek Basin, Colorado

Appendix 4. Results of ICP–MS analyses.

[mg/L, micrograms per liter; EB,equipment blank; FA, filtered, acidified; –R (appended to sample name), replicate sample; RA, unfiltered, acidified]

Constituent 

(mg/L)

Sample and treatment

EC–CELK1–01 EC–CELK1–01 EC–CELK1–02 EC–CELK1–02 EC–CELK1–03 EC–CELK1–03 EC–CELK1–04

FA RA FA RA FA RA FA

Ag <1 <1 <1 <1 <1 <1 <1

Al 5.0 8.6 15.7 42.0 3.4 7.5 13.1

As 2 2 1 1 1 1 1

Ba 14.5 15.2 13.7 13.4 16.9 16.1 12.6

Be <0.05 <0.05 <0.05 <0.05 <0.05 <0.05 <0.05

Bi < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2

Cd 2.20 2.35 5.17 5.15 2.70 2.56 2.36

Ce 0.03 0.06 0.25 0.54 0.04 0.06 0.10

Co <0.02 <0.02 0.24 0.23 <0.02 <0.02 0.03

Cr <1 <1 <1 <1 <1 <1 <1

Cs < 0.02 < 0.02 < 0.02 < 0.02 < 0.02 < 0.02 < 0.02

Cu 2.0 2.1 4.7 6.3 1.8 2.1 2.7

Dy 0.006 0.008 0.02 0.04 0.007 0.01 0.02

Er < 0.005 0.005 0.009 0.02 < 0.005 < 0.005 0.008

Eu < 0.005 < 0.005 0.01 0.02 < 0.005 0.005 0.006

Ga < 0.05 < 0.05 < 0.05 < 0.05 < 0.05 < 0.05 < 0.05

Gd 0.01 0.01 0.02 0.063 0.008 0.008 0.02

Ge < 0.05 < 0.05 < 0.05 < 0.05 < 0.05 < 0.05 < 0.05

Ho < 0.005 < 0.005 < 0.005 0.007 < 0.005 < 0.005 < 0.005

K 340 340 450 420 430 500 390

La 0.06 0.09 0.20 0.36 0.08 0.09 0.14

Li 1.8 2.2 2.0 2.0 2.4 1.5 1.2

Lu < 0.1 < 0.1 < 0.1 < 0.1 < 0.1 < 0.1 < 0.1

Mn 12.9 14.1 168 160 7.2 8.2 30.9

Mo < 2 < 2 < 2 < 2 < 2 < 2 < 2

Nb < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2

Nd 0.04 0.08 0.16 0.30 0.05 0.06 0.12

Ni <0.4 <0.4 0.6 0.6 0.4 0.4 <0.4

P <10 <10 <10 <10 <10 <10 <10

Pb 0.4 0.95 1.8 7.4 0.3 0.66 0.5

Pr 0.01 0.02 0.04 0.07 0.01 0.02 0.03

Rb 0.33 0.34 0.41 0.42 0.33 0.32 0.30

Sb 0.42 <0.3 <0.3 <0.3 <0.3 <0.3 <0.3

Sc 0.6 0.6 < 0.6 < 0.6 < 0.6 < 0.6 < 0.6

Se < 1 < 1 < 1 < 1 < 1 < 1 < 1

Sm < 0.01 0.02 0.02 0.05 < 0.01 < 0.01 0.02

Sr 152 154 147 152 248 233 197

Ta 0.06 0.02 < 0.02 < 0.02 < 0.02 < 0.02 < 0.02

Tb < 0.005 < 0.005 < 0.005 0.007 < 0.005 < 0.005 < 0.005

Th < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2

Ti < 0.5 < 0.5 < 0.5 < 0.5 0.6 0.9 0.5

Tl <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1

Tm < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005

U < 0.1 < 0.1 < 0.1 < 0.1 < 0.1 < 0.1 < 0.1

V <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5

W < 0.5 < 0.5 < 0.5 < 0.5 < 0.5 < 0.5 < 0.5

Y 0.04 0.06 0.11 0.20 0.06 0.05 0.12

Yb < 0.005 < 0.005 0.009 0.01 < 0.005 < 0.005 0.008

Zn 428 432 986 991 626 582 553

Zr < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2
Appendix 4 117

Appendix 4. Results of ICP–MS analyses.—Continued

[mg/L, micrograms per liter; EB,equipment blank; FA, filtered, acidified; –R (appended to sample name), replicate sample; RA, unfiltered, acidified]

Sample and treatment

Constituent 

(mg/L)

EC–CELK1–04 EC–CELK1–05 EC–CELK1–05 EC–CELK1–06 EC–CELK1–06 EC–CELK1–07 EC–CELK1–07

RA FA RA FA RA FA RA

Ag <1 <1 <1 <1 <1 <1 <1

Al 25.0 45.9 128 45.2 164 47.7 93.0

As 1 <1 1 <1 1 1 2

Ba 12.1 9.16 9.04 8.33 8.11 10.8 10.4

Be <0.05 <0.05 <0.05 <0.05 0.08 <0.05 0.06

Bi < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2

Cd 2.32 3.76 3.66 4.92 4.88 3.93 3.81

Ce 0.16 0.63 1.07 0.86 1.65 0.54 0.88

Co 0.04 0.24 0.23 0.42 0.45 0.21 0.24

Cr <1 <1 <1 <1 <1 <1 <1

Cs < 0.02 < 0.02 0.03 < 0.02 0.03 < 0.02 0.02

Cu 3.6 9.3 12.5 12.4 20.1 11.1 14.5

Dy 0.02 0.060 0.095 0.070 0.13 0.054 0.082

Er 0.01 0.04 0.04 0.04 0.059 0.02 0.04

Eu 0.007 0.02 0.03 0.02 0.05 0.02 0.02

Ga < 0.05 < 0.05 < 0.05 < 0.05 < 0.05 < 0.05 < 0.05

Gd 0.03 0.078 0.13 0.091 0.18 0.081 0.11

Ge < 0.05 < 0.05 < 0.05 < 0.05 < 0.05 < 0.05 < 0.05

Ho < 0.005 0.01 0.02 0.01 0.02 0.01 0.01

K 430 360 400 320 370 350 390

La 0.19 0.54 0.77 0.62 1.06 0.41 0.65

Li 0.7 0.7 0.3 0.8 0.8 1.1 0.8

Lu < 0.1 < 0.1 < 0.1 < 0.1 < 0.1 < 0.1 < 0.1

Mn 31.2 118 118 175 183 114 117

Mo < 2 < 2 < 2 < 2 < 2 < 2 < 2

Nb < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2

Nd 0.14 0.45 0.63 0.52 0.96 0.34 0.59

Ni <0.4 0.5 0.5 0.8 0.6 0.5 0.5

P <10 <10 <10 <10 <10 <10 <10

Pb 1.1 2.8 10.6 2.6 17.3 6.6 16.1

Pr 0.04 0.11 0.17 0.13 0.25 0.09 0.15

Rb 0.29 0.29 0.36 0.29 0.36 0.33 0.38

Sb <0.3 <0.3 <0.3 <0.3 <0.3 <0.3 <0.3

Sc 0.6 < 0.6 < 0.6 < 0.6 < 0.6 < 0.6 < 0.6

Se < 1 < 1 < 1 < 1 < 1 < 1 < 1

Sm 0.03 0.07 0.13 0.11 0.16 0.07 0.10

Sr 185 97.9 94.3 77.1 73.4 88.5 85.5

Ta < 0.02 < 0.02 < 0.02 < 0.02 < 0.02 < 0.02 < 0.02

Tb 0.005 0.01 0.02 0.02 0.03 0.01 0.02

Th < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2

Ti 0.6 0.6 1.1 0.5 1.0 < 0.5 0.9

Tl <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1

Tm < 0.005 < 0.005 0.005 < 0.005 0.007 < 0.005 0.005

U < 0.1 < 0.1 < 0.1 < 0.1 < 0.1 < 0.1 < 0.1

V <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5

W < 0.5 < 0.5 < 0.5 < 0.5 < 0.5 < 0.5 < 0.5

Y 0.14 0.37 0.55 0.40 0.67 0.27 0.40

Yb 0.007 0.02 0.04 0.02 0.04 0.01 0.03

Zn 513 664 654 826 823 643 633

Zr < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2
118 Hydrogeochemical Investigation of the Standard Mine Vicinity, Upper Elk Creek Basin, Colorado

Appendix 4. Results of ICP–MS analyses.—Continued

[mg/L, micrograms per liter; EB,equipment blank; FA, filtered, acidified; –R (appended to sample name), replicate sample; RA, unfiltered, acidified]

Constituent 

(mg/L)

Sample and treatment

EC–CELK1–08 EC–CELK1–08 EC–T1–01 EC–T1–01 EC–T2–01 EC–T2–01 EC–T3–01 EC–T3–01 EC–S1–01

FA RA FA RA FA RA FA RA FA

Ag <1 <1 <1 <1 <1 <1 <1 <1 <1

Al 42.0 66.5 13.9 46.1 2.3 7.0 7.6 75.6 9910

As 2 2 <1 <1 <1 <1 <1 <1 <1

Ba 12.8 11.8 5.16 6.24 3.86 4.25 10.8 12.5 23.6

Be <0.05 <0.05 <0.05 <0.05 <0.05 <0.05 <0.05 <0.05 11.7

Bi < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2

Cd 2.79 2.67 0.06 0.11 0.12 0.15 0.02 0.03 197

Ce 0.31 0.51 0.11 0.34 < 0.01 0.03 0.06 0.41 288

Co 0.11 0.14 0.02 0.12 <0.02 <0.02 0.03 0.08 34.2

Cr <1 <1 <1 <1 <1 <1 <1 <1 <1

Cs < 0.02 < 0.02 < 0.02 0.02 0.03 0.05 < 0.02 0.05 0.86

Cu 7.0 8.5 <0.5 0.98 <0.5 <0.5 <0.5 1.0 625

Dy 0.03 0.04 0.02 0.04 < 0.005 0.005 0.02 0.066 14.6

Er 0.02 0.02 0.01 0.02 < 0.005 < 0.005 0.007 0.03 6.06

Eu 0.01 0.02 0.005 0.01 < 0.005 < 0.005 0.006 0.02 6.60

Ga < 0.05 < 0.05 < 0.05 < 0.05 < 0.05 < 0.05 < 0.05 < 0.05 2.0

Gd 0.05 0.074 0.02 0.055 < 0.005 0.006 0.02 0.093 24.0

Ge < 0.05 < 0.05 < 0.05 < 0.05 < 0.05 < 0.05 < 0.05 < 0.05 0.32

Ho 0.006 0.006 < 0.005 0.007 < 0.005 < 0.005 < 0.005 0.01 2.4

K 410 440 200 200 400 390 370 390 850

La 0.29 0.44 0.08 0.21 < 0.01 0.01 0.08 0.51 139

Li 1.7 0.9 0.4 0.4 2.4 2.8 0.3 0.4 33.1

Lu < 0.1 < 0.1 < 0.1 < 0.1 < 0.1 < 0.1 < 0.1 < 0.1 0.5

Mn 61.4 68.0 17.3 71.2 10.4 23.6 27.1 52.8 23500

Mo < 2 < 2 < 2 < 2 < 2 < 2 < 2 < 2 < 2

Nb < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2

Nd 0.25 0.38 0.11 0.28 < 0.01 0.02 0.10 0.52 137

Ni <0.4 0.4 <0.4 <0.4 <0.4 <0.4 <0.4 <0.4 25.2

P <10 <10 <10 <10 <10 <10 <10 <10 <10

Pb 4.6 10.4 0.87 6.3 0.09 0.68 0.4 2.6 1160

Pr 0.06 0.10 0.02 0.06 < 0.01 < 0.01 0.02 0.13 34.2

Rb 0.41 0.42 0.54 0.62 1.13 1.14 0.33 0.50 3.60

Sb <0.3 <0.3 <0.3 <0.3 <0.3 <0.3 <0.3 <0.3 <0.3

Sc < 0.6 < 0.6 < 0.6 < 0.6 0.6 0.7 < 0.6 < 0.6 4.6

Se < 1 < 1 < 1 < 1 < 1 < 1 < 1 < 1 2.5

Sm 0.05 0.06 0.02 0.05 < 0.01 < 0.01 0.02 0.11 25.1

Sr 115 104 26.2 25.8 83.8 80.9 43.2 44.2 226

Ta < 0.02 < 0.02 0.1 < 0.02 0.1 < 0.02 0.08 < 0.02 0.05

Tb 0.006 0.009 < 0.005 0.008 < 0.005 < 0.005 < 0.005 0.01 3.02

Th < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 1.94

Ti < 0.5 1.0 < 0.5 0.9 < 0.5 < 0.5 < 0.5 1.2 4.2

Tl <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1

Tm < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 0.67

U < 0.1 < 0.1 < 0.1 < 0.1 < 0.1 < 0.1 < 0.1 < 0.1 1.49

V <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5

W < 0.5 < 0.5 < 0.5 < 0.5 < 0.5 < 0.5 < 0.5 < 0.5 < 0.5

Y 0.21 0.26 0.11 0.21 0.01 0.02 0.08 0.34 61.3

Yb 0.01 0.01 0.01 0.01 < 0.005 < 0.005 0.007 0.03 4.10

Zn 451 423 7.4 12.3 31.3 33.9 3.3 3.9 25600

Zr < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2
Appendix 4. Results of ICP–MS analyses.—Continued

[mg/L, micrograms per liter; EB,equipment blank; FA, filtered, acidified; –R (appended to sample name), replicate sample; RA, unfiltered, acidified]

Constituent 

(mg/L)

Sample and treatment

EC–S1–01 EC–S2–01 EC–S2–01 EC–S2–03 EC–S2–03 EC–S2–04 EC–S2–04 EC–S3–01 EC–S3–01 EC–S4–01

RA FA RA FA RA FA RA FA RA FA

Ag <1 <1 <1 <1 <1 <1 <1 <1 <1 <1

Al 9020 <2 6.2 28.9 5.4 13.9 22.6 <2 17.9 <2

As <1 <1 <1 <1 <1 <1 <1 <1 <1 <1

Ba 22.6 7.46 7.27 8.92 6.60 4.65 4.31 2.68 2.94 3.57

Be 11.5 <0.05 <0.05 <0.05 <0.05 <0.05 <0.05 <0.05 <0.05 <0.05

Bi < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2

Cd 186 0.52 0.51 0.67 0.47 0.32 0.27 <0.02 <0.02 <0.02

Ce 292 < 0.01 0.03 0.12 0.03 0.02 0.08 < 0.01 0.11 < 0.01

Co 32.3 <0.02 <0.02 0.10 <0.02 <0.02 <0.02 <0.02 <0.02 <0.02

Cr <1 <1 <1 <1 <1 <1 <1 <1 <1 <1

Cs 0.82 0.14 0.15 0.13 0.13 0.08 0.10 0.18 0.25 0.04

Cu 596 <0.5 0.5 10.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5

Dy 14.6 < 0.005 0.007 0.01 0.005 0.005 0.009 0.02 0.075 < 0.005

Er 5.99 < 0.005 0.005 0.007 < 0.005 < 0.005 < 0.005 0.01 0.04 < 0.005

Eu 6.36 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 0.007 0.02 < 0.005

Ga 1.9 < 0.05 < 0.05 < 0.05 < 0.05 < 0.05 < 0.05 < 0.05 < 0.05 < 0.05

Gd 22.9 < 0.005 0.009 0.01 0.01 0.007 0.02 0.03 0.11 < 0.005

Ge 0.30 < 0.05 < 0.05 < 0.05 < 0.05 < 0.05 < 0.05 < 0.05 < 0.05 < 0.05

Ho 2.4 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 0.01 < 0.005

K 790 470 460 1710 410 370 400 300 300 200

La 141 0.03 0.04 0.09 0.04 0.03 0.05 0.18 0.52 0.01

Li 32.4 2.3 2.8 2.3 1.8 1.8 0.7 0.8 1.0 1.1

Lu 0.5 < 0.1 < 0.1 < 0.1 < 0.1 < 0.1 < 0.1 < 0.1 < 0.1 < 0.1

Mn 22600 <0.2 0.5 5.9 0.4 <0.2 0.9 <0.2 1.3 <0.2

Mo < 2 < 2 < 2 < 2 < 2 < 2 < 2 < 2 < 2 < 2

Nb < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2

Nd 135 0.02 0.05 0.08 0.05 0.04 0.07 0.19 0.59 0.01

Ni 23.8 <0.4 <0.4 3.0 <0.4 <0.4 <0.4 <0.4 <0.4 <0.4

P <10 <10 10 90 <10 <10 <10 <10 10 <10

Pb 1140 0.1 0.5 4.1 0.4 0.1 0.61 <0.05 <0.05 0.06

Pr 33.6 < 0.01 0.01 0.02 0.01 < 0.01 0.01 0.04 0.13 < 0.01

Rb 3.54 1.29 1.28 1.84 1.16 0.86 0.85 0.60 0.64 0.26

Sb <0.3 <0.3 <0.3 <0.3 <0.3 <0.3 <0.3 <0.3 0.40 0.3

Sc 4.0 0.7 0.8 0.8 0.6 < 0.6 0.7 < 0.6 < 0.6 < 0.6

Se 2.2 < 1 < 1 < 1 < 1 < 1 < 1 < 1 < 1 < 1

Sm 24.8 < 0.01 < 0.01 0.02 < 0.01 < 0.01 0.01 0.03 0.12 < 0.01

Sr 227 88.3 84.0 80.1 81.4 50.1 46.3 48.0 46.4 135

Ta 0.03 0.07 < 0.02 < 0.02 < 0.02 < 0.02 < 0.02 0.06 0.06 0.05

Tb 2.97 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 0.02 < 0.005

Th 1.80 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2

Ti 3.8 < 0.5 < 0.5 1.3 < 0.5 < 0.5 < 0.5 < 0.5 < 0.5 < 0.5

Tl <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1

Tm 0.69 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 0.005 < 0.005

U 1.40 < 0.1 < 0.1 < 0.1 < 0.1 < 0.1 < 0.1 < 0.1 < 0.1 < 0.1

V <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5

W < 0.5 < 0.5 < 0.5 < 0.5 < 0.5 < 0.5 < 0.5 < 0.5 < 0.5 < 0.5

Y 61.2 0.04 0.06 0.08 0.05 0.03 0.06 0.13 0.36 0.01

Yb 4.01 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 0.005 0.02 < 0.005

Zn 25000 102 98.2 162 93.5 67.0 59.7 2.6 2.9 1.2

Zr < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2

Appendix 4 119
120 Hydrogeochemical Investigation of the Standard Mine Vicinity, Upper Elk Creek Basin, Colorado

Appendix 4. Results of ICP–MS analyses.—Continued

[mg/L, micrograms per liter; EB,equipment blank; FA, filtered, acidified; –R (appended to sample name), replicate sample; RA, unfiltered, acidified]

Constituent 

(mg/L)

Sample and treatment

EC–S4–01 EC–S5–01 EC–S5–01 EC–S7–01 EC–S7–01 EC–S8A–01 EC–S8A–01 EC–S8A–03

RA FA RA FA RA FA RA FA

Ag <1 <1 <1 <1 <1 <1 <1 <1

Al 3.9 7.8 227 <2 6.5 2.2 366 <2

As <1 <1 <1 <1 <1 <1 2 <1

Ba 3.57 9.63 12.8 4.83 5.09 5.32 8.52 4.49

Be <0.05 <0.05 <0.05 <0.05 <0.05 <0.05 <0.05 <0.05

Bi < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2

Cd <0.02 0.06 0.10 <0.02 <0.02 <0.02 0.02 <0.02

Ce < 0.01 0.06 0.77 < 0.01 0.02 0.01 2.41 < 0.01

Co <0.02 0.13 0.26 <0.02 <0.02 <0.02 0.14 <0.02

Cr <1 <1 <1 <1 <1 <1 <1 <1

Cs 0.05 0.02 0.18 < 0.02 0.02 0.12 1.02 0.10

Cu <0.5 <0.5 1.2 <0.5 <0.5 <0.5 1.2 <0.5

Dy < 0.005 0.02 0.078 < 0.005 < 0.005 0.005 0.26 0.007

Er < 0.005 0.007 0.04 < 0.005 < 0.005 < 0.005 0.12 < 0.005

Eu < 0.005 0.005 0.02 < 0.005 < 0.005 < 0.005 0.11 < 0.005

Ga < 0.05 < 0.05 0.07 < 0.05 < 0.05 < 0.05 0.1 < 0.05

Gd 0.005 0.02 0.13 < 0.005 0.006 0.006 0.46 0.01

Ge < 0.05 < 0.05 < 0.05 < 0.05 < 0.05 < 0.05 < 0.05 < 0.05

Ho < 0.005 < 0.005 0.02 < 0.005 < 0.005 < 0.005 0.051 < 0.005

K 200 570 660 100 100 400 420 360

La 0.01 0.08 0.59 < 0.01 0.02 0.03 1.57 0.03

Li 1.2 0.3 0.8 0.8 1.1 3.2 4.7 3.1

Lu < 0.1 < 0.1 < 0.1 < 0.1 < 0.1 < 0.1 < 0.1 < 0.1

Mn <0.2 106 138 0.3 0.8 0.7 36.4 <0.2

Mo < 2 < 2 < 2 < 2 < 2 < 2 < 2 < 2

Nb < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2

Nd 0.02 0.09 0.62 < 0.01 0.02 0.03 1.90 0.03

Ni <0.4 <0.4 0.4 <0.4 <0.4 <0.4 <0.4 <0.4

P 10 <10 20 <10 <10 <10 20 <10

Pb <0.05 4.3 22.4 <0.05 0.1 0.4 2.8 <0.05

Pr < 0.01 0.02 0.14 < 0.01 < 0.01 < 0.01 0.41 < 0.01

Rb 0.28 0.62 1.29 0.13 0.16 0.68 1.56 0.67

Sb <0.3 <0.3 <0.3 0.34 <0.3 <0.3 <0.3 <0.3

Sc 0.6 < 0.6 0.6 < 0.6 0.6 0.8 1.0 0.8

Se < 1 < 1 < 1 < 1 < 1 < 1 < 1 < 1

Sm < 0.01 0.02 0.11 < 0.01 < 0.01 < 0.01 0.38 < 0.01

Sr 135 42.0 42.9 54.7 54.4 136 134 111

Ta < 0.02 0.07 < 0.02 0.2 0.03 0.02 < 0.02 < 0.02

Tb < 0.005 < 0.005 0.02 < 0.005 < 0.005 < 0.005 0.053 < 0.005

Th < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2

Ti < 0.5 < 0.5 4.5 < 0.5 < 0.5 0.6 4.9 < 0.5

Tl <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1

Tm < 0.005 < 0.005 0.005 < 0.005 < 0.005 < 0.005 0.01 < 0.005

U < 0.1 < 0.1 < 0.1 < 0.1 < 0.1 < 0.1 0.12 < 0.1

V <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5

W < 0.5 < 0.5 < 0.5 < 0.5 < 0.5 < 0.5 < 0.5 < 0.5

Y 0.02 0.10 0.40 < 0.01 0.02 0.04 1.64 0.05

Yb < 0.005 0.01 0.03 < 0.005 < 0.005 < 0.005 0.06 < 0.005

Zn <0.5 14.7 17.8 0.5 0.9 2.4 4.4 <0.5

Zr < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2
Appendix 4. Results of ICP–MS analyses.—Continued

[mg/L, micrograms per liter; EB,equipment blank; FA, filtered, acidified; –R (appended to sample name), replicate sample; RA, unfiltered, acidified]

Constituent 

(mg/L)

Sample and treatment

EC–S8A–03 EC–S8A–04 EC–S8A–04 EC–S8B–01 EC–S8B–01 EC–S9–01 EC–S9–01 EC–S10–01 EC–S10–01

RA FA RA FA RA FA RA FA RA

Ag <1 <1 <1 <1 <1 <1 <1 <1 12.0

Al 23.0 68.7 88.4 <2 172 4.0 64.0 1070 1820

As <1 <1 1 <1 2 <1 <1 <1 <1

Ba 4.64 5.01 5.34 5.04 6.46 3.85 4.22 35.8 37.2

Be <0.05 <0.05 <0.05 <0.05 <0.05 <0.05 <0.05 1.9 2.1

Bi < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2

Cd <0.02 <0.02 <0.02 <0.02 0.02 0.38 0.43 26.2 26.2

Ce 0.16 0.04 0.36 0.02 1.52 0.02 0.18 7.60 11.2

Co <0.02 <0.02 0.05 <0.02 0.09 <0.02 0.03 0.17 0.26

Cr <1 <1 <1 <1 <1 <1 <1 <1 <1

Cs 0.15 0.09 0.37 0.13 0.57 < 0.02 0.05 0.29 1.06

Cu <0.5 <0.5 0.5 <0.5 0.71 <0.5 <0.5 38.8 60.2

Dy 0.03 0.01 0.04 0.008 0.20 < 0.005 0.008 1.77 2.88

Er 0.01 < 0.005 0.02 < 0.005 0.093 < 0.005 < 0.005 0.75 1.28

Eu 0.009 0.005 0.02 < 0.005 0.093 < 0.005 0.005 0.59 1.19

Ga < 0.05 < 0.05 < 0.05 < 0.05 0.05 < 0.05 < 0.05 0.1 0.30

Gd 0.04 0.02 0.062 0.01 0.37 < 0.005 0.02 2.67 4.72

Ge < 0.05 < 0.05 < 0.05 < 0.05 < 0.05 < 0.05 < 0.05 < 0.05 0.07

Ho 0.005 < 0.005 0.008 < 0.005 0.04 < 0.005 < 0.005 0.3 0.5

K 340 380 450 650 830 380 360 940 1220

La 0.14 0.06 0.26 0.05 1.39 0.01 0.08 14.8 19.0

Li 2.7 3.3 2.4 3.3 3.9 2.3 2.7 10.1 11.3

Lu < 0.1 < 0.1 < 0.1 < 0.1 < 0.1 < 0.1 < 0.1 < 0.1 0.1

Mn 1.8 <0.2 12.4 0.6 23.9 8.2 16.3 782 780

Mo < 2 < 2 < 2 < 2 < 2 < 2 < 2 < 2 < 2

Nb < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 0.44 < 0.2 < 0.2

Nd 0.15 0.08 0.28 0.05 1.76 0.02 0.08 13.8 24.3

Ni <0.4 <0.4 <0.4 <0.4 <0.4 0.5 0.5 4.3 4.6

P <10 <10 10 <10 20 <10 <10 <10 40

Pb 0.1 0.07 0.60 0.2 1.2 0.1 1.0 219 279

Pr 0.03 0.02 0.07 0.01 0.38 < 0.01 0.02 3.45 5.62

Rb 0.70 0.68 0.92 1.14 1.64 0.54 0.69 2.32 3.26

Sb <0.3 <0.3 <0.3 <0.3 <0.3 <0.3 0.33 <0.3 <0.3

Sc 0.6 < 0.6 0.7 0.8 1.0 < 0.6 0.6 1.3 1.8

Se < 1 < 1 < 1 < 1 < 1 < 1 < 1 < 1 < 1

Sm 0.02 0.02 0.05 < 0.01 0.36 < 0.01 0.02 2.40 4.94

Sr 114 123 116 132 132 90.6 87.0 111 111

Ta < 0.02 < 0.02 < 0.02 < 0.02 < 0.02 0.05 0.07 < 0.02 < 0.02

Tb 0.005 < 0.005 0.009 < 0.005 0.04 < 0.005 < 0.005 0.36 0.60

Th < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2

Ti 0.8 0.5 2.7 0.5 2.9 < 0.5 2.2 1.0 12

Tl <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1

Tm < 0.005 < 0.005 < 0.005 < 0.005 0.01 < 0.005 < 0.005 0.090 0.15

U < 0.1 < 0.1 < 0.1 < 0.1 < 0.1 < 0.1 < 0.1 < 0.1 0.36

V <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 0.5

W < 0.5 < 0.5 < 0.5 < 0.5 < 0.5 < 0.5 < 0.5 < 0.5 < 0.5

Y 0.15 0.09 0.26 0.06 1.14 0.02 0.05 8.28 10.9

Yb 0.006 < 0.005 0.01 < 0.005 0.05 < 0.005 < 0.005 0.51 0.94

Zn <0.5 <0.5 1.0 1.1 2.5 198 193 3400 3320

Zr < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2

Appendix 4 121
122 Hydrogeochemical Investigation of the Standard Mine Vicinity, Upper Elk Creek Basin, Colorado

Appendix 4. Results of ICP–MS analyses.—Continued

[mg/L, micrograms per liter; EB,equipment blank; FA, filtered, acidified; –R (appended to sample name), replicate sample; RA, unfiltered, acidified]

Constituent 

(mg/L)

Sample and treatment

EC–S11–01 EC–S11–01 EC–S11–01–R EC–S11–01–R EC–S12–01 EC–S12–01 EC–MUSTD1–01

FA RA FA RA FA RA FA

Ag <1 <1 <1 <1 <1 <1 1.2

Al 3.9 9.3 4.0 8.8 <2 32.3 3670

As <1 <1 <1 <1 4.4 4.5 <1

Ba 8.73 8.35 8.81 8.90 5.75 5.80 16.5

Be <0.05 <0.05 <0.05 <0.05 <0.05 <0.05 3.1

Bi < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2

Cd 5.53 5.30 5.48 5.45 <0.02 <0.02 190

Ce 0.03 0.04 0.02 0.03 0.34 0.15 53.0

Co 0.05 0.05 0.04 0.05 <0.02 <0.02 19.9

Cr <1 <1 <1 <1 <1 <1 <1

Cs < 0.02 0.02 < 0.02 0.02 0.11 0.15 0.41

Cu 6.2 9.0 5.8 8.7 <0.5 0.59 1080

Dy 0.01 0.01 0.01 0.01 0.006 0.02 3.04

Er 0.007 0.009 0.007 0.008 < 0.005 < 0.005 1.29

Eu < 0.005 0.007 0.005 0.006 < 0.005 0.007 1.16

Ga < 0.05 < 0.05 < 0.05 < 0.05 < 0.05 < 0.05 0.44

Gd 0.01 0.02 0.02 0.02 0.02 0.02 4.49

Ge < 0.05 < 0.05 < 0.05 < 0.05 < 0.05 < 0.05 0.06

Ho < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 0.52

K 320 310 310 320 490 430 580

La 0.07 0.08 0.07 0.08 0.20 0.14 27.2

Li 0.3 1.2 0.4 0.5 3.5 3.4 19.0

Lu < 0.1 < 0.1 < 0.1 < 0.1 < 0.1 < 0.1 0.1

Mn 6.6 6.6 6.5 6.9 0.6 1.6 5380

Mo < 2 < 2 < 2 < 2 < 2 < 2 < 2

Nb < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2

Nd 0.09 0.09 0.08 0.10 0.14 0.13 24.6

Ni <0.4 <0.4 <0.4 <0.4 <0.4 <0.4 15.4

P <10 <10 <10 <10 <10 10 <10

Pb 95.7 102 96.7 102 1.4 0.52 604

Pr 0.02 0.02 0.02 0.02 0.04 0.03 6.41

Rb 0.50 0.52 0.49 0.52 0.75 0.83 1.91

Sb <0.3 <0.3 <0.3 <0.3 <0.3 <0.3 0.45

Sc < 0.6 < 0.6 < 0.6 < 0.6 0.8 0.8 1.7

Se < 1 < 1 < 1 < 1 < 1 < 1 1.5

Sm 0.01 0.02 0.02 0.02 0.01 0.03 4.50

Sr 37.5 36.7 37.7 36.7 157 156 146

Ta 0.06 < 0.02 0.06 < 0.02 < 0.02 0.03 0.06

Tb < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 0.61

Th < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 0.30

Ti < 0.5 < 0.5 < 0.5 < 0.5 0.7 1.4 2.2

Tl <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1

Tm < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 0.14

U < 0.1 < 0.1 < 0.1 < 0.1 < 0.1 < 0.1 0.31

V <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5

W < 0.5 < 0.5 < 0.5 < 0.5 < 0.5 < 0.5 < 0.5

Y 0.08 0.09 0.08 0.09 0.04 0.08 12.9

Yb 0.006 0.008 < 0.005 0.005 < 0.005 < 0.005 0.84

Zn 883 873 876 893 2.0 1.4 24400

Zr < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2
Appendix 4. Results of ICP–MS analyses.—Continued

[mg/L, micrograms per liter; EB,equipment blank; FA, filtered, acidified; –R (appended to sample name), replicate sample; RA, unfiltered, acidified]

Constituent 

(mg/L)

Sample and treatment

EC–MUSTD1–01 RW–S1–01 RW–S1–01 RW–S2–01 RW–S2–01 RW–S2–01–R RW–S2–01–R EC–P4–01 EC–P4–01

RA FA RA FA RA FA RA FA RA

Ag 1.1 <1 <1 <1 <1 <1 <1 <1 4.8

Al 3330 7.9 36.0 2550 2340 2590 2280 9.6 59.0

As <1 <1 <1 6.8 7.8 7.0 7.6 <1 2

Ba 15.6 7.33 7.16 15.9 15.5 16.0 15.1 39.7 41.8

Be 2.8 <0.05 <0.05 0.7 0.7 0.8 0.7 <0.05 <0.05

Bi < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 0.66

Cd 181 0.70 0.68 54.0 54.2 55.3 52.6 0.71 0.90

Ce 51.0 0.02 0.16 5.02 4.95 5.12 4.93 0.06 0.39

Co 19.1 <0.02 <0.02 5.96 5.86 6.01 5.65 0.20 0.27

Cr <1 <1 <1 <1 <1 <1 <1 <1 <1

Cs 0.40 0.10 0.20 0.76 0.75 0.79 0.73 < 0.02 0.06

Cu 1030 <0.5 0.86 4.8 4.9 4.8 5.0 <0.5 71.2

Dy 3.09 0.03 0.071 0.52 0.53 0.53 0.50 0.006 0.02

Er 1.26 0.01 0.03 0.36 0.34 0.35 0.36 < 0.005 0.01

Eu 1.10 0.006 0.02 0.096 0.092 0.091 0.092 0.006 0.01

Ga 0.43 < 0.05 < 0.05 0.2 0.2 0.2 0.2 < 0.05 < 0.05

Gd 4.33 0.04 0.095 0.53 0.54 0.58 0.54 0.005 0.03

Ge 0.06 < 0.05 < 0.05 < 0.05 < 0.05 < 0.05 < 0.05 < 0.05 < 0.05

Ho 0.50 0.005 0.01 0.11 0.1 0.12 0.11 < 0.005 0.005

K 540 310 300 1160 1120 1180 1100 610 670

La 26.3 0.22 0.48 2.60 2.57 2.62 2.50 0.03 0.21

Li 17.2 1.0 1.4 4.9 4.8 4.6 5.2 0.9 0.9

Lu 0.1 < 0.1 < 0.1 < 0.1 < 0.1 < 0.1 < 0.1 < 0.1 < 0.1

Mn 5190 5.1 12.3 1360 1340 1410 1310 81.0 93.1

Mo < 2 < 2 < 2 < 2 < 2 < 2 < 2 < 2 < 2

Nb < 0.2 < 0.2 < 0.2 0.3 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2

Nd 23.7 0.17 0.46 2.30 2.18 2.26 2.15 0.03 0.17

Ni 15.0 <0.4 <0.4 3.5 3.6 3.6 3.4 0.7 0.9

P <10 <10 <10 40 60 40 60 <10 20

Pb 588 1.5 4.5 1730 1700 1720 1650 357 944

Pr 6.14 0.04 0.11 0.57 0.56 0.57 0.56 < 0.01 0.04

Rb 1.86 0.68 0.75 12.9 12.6 13.2 12.3 0.47 0.70

Sb <0.3 <0.3 <0.3 <0.3 <0.3 <0.3 <0.3 <0.3 0.97

Sc 1.4 < 0.6 < 0.6 1.3 1.5 1.3 1.4 < 0.6 < 0.6

Se 1.2 < 1 < 1 < 1 < 1 < 1 < 1 < 1 1.1

Sm 4.36 0.03 0.09 0.46 0.44 0.43 0.46 < 0.01 0.04

Sr 146 59.3 55.2 16.8 16.4 17.2 15.9 29.8 30.2

Ta < 0.02 0.1 0.02 0.09 0.03 0.05 0.02 0.09 < 0.02

Tb 0.58 0.005 0.01 0.084 0.083 0.091 0.081 < 0.005 < 0.005

Th 0.24 < 0.2 < 0.2 0.42 0.48 0.43 0.48 < 0.2 < 0.2

Ti 1.9 < 0.5 0.8 1.3 1.2 1.1 1.1 < 0.5 1.0

Tl <0.1 <0.1 <0.1 0.3 0.2 0.3 0.2 <0.1 <0.1

Tm 0.14 < 0.005 < 0.005 0.060 0.056 0.057 0.053 < 0.005 < 0.005

U 0.28 < 0.1 < 0.1 1.16 1.07 1.17 1.05 < 0.1 < 0.1

V <0.5 <0.5 <0.5 1.5 1.6 1.5 1.6 <0.5 <0.5

W < 0.5 < 0.5 < 0.5 < 0.5 < 0.5 < 0.5 < 0.5 < 0.5 < 0.5

Y 12.7 0.21 0.46 3.75 3.73 3.80 3.68 0.02 0.10

Yb 0.87 0.006 0.02 0.46 0.46 0.44 0.42 < 0.005 0.008

Zn 23900 148 145 5760 5560 5880 5440 166 194

Zr < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2

Appendix 4 123
124 Hydrogeochemical Investigation of the Standard Mine Vicinity, Upper Elk Creek Basin, Colorado

Appendix 4. Results of ICP–MS analyses.—Continued

[mg/L, micrograms per liter; EB,equipment blank; FA, filtered, acidified; –R (appended to sample name), replicate sample; RA, unfiltered, acidified]

Constituent 

(mg/L)

Sample and treatment

EC–P5–01 EC–P5–01 EC–MSTD1–01 EC–MSTD1–01 EC–MSTD1–02 EC–MSTD1–02 EC–MSTD1–02R

FA RA FA RA FA RA FA

Ag <1 <1 <1 <1 <1 <1 <1

Al 47.6 61.1 324 716 194 637 199

As <1 <1 <1 1 <1 1 <1

Ba 38.8 40.3 13.7 13.1 13.7 13.3 14.5

Be 0.3 0.3 1.0 1.3 0.7 1.0 0.8

Bi < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2

Cd 4.82 5.14 154 154 151 148 156

Ce 0.26 0.39 15.1 15.3 12.4 13.3 12.6

Co 0.14 0.16 15.8 15.4 15.3 15.0 15.9

Cr <1 <1 <1 <1 <1 <1 <1

Cs 0.03 0.04 0.48 0.45 0.48 0.46 0.51

Cu <0.5 2.4 399 414 225 258 236

Dy 0.02 0.03 1.16 1.24 0.89 1.07 0.93

Er 0.01 0.01 0.48 0.53 0.36 0.44 0.37

Eu 0.01 0.02 0.39 0.41 0.31 0.35 0.30

Ga < 0.05 < 0.05 0.26 0.23 0.26 0.25 0.25

Gd 0.04 0.053 1.73 1.87 1.31 1.59 1.41

Ge < 0.05 < 0.05 < 0.05 < 0.05 < 0.05 < 0.05 < 0.05

Ho < 0.005 0.006 0.20 0.22 0.15 0.18 0.16

K 440 440 880 820 910 860 940

La 0.30 0.42 11.4 11.6 10.4 10.8 10.6

Li 2.4 2.8 14.2 14.1 15.9 15.1 16.8

Lu < 0.1 < 0.1 < 0.1 < 0.1 < 0.1 < 0.1 < 0.1

Mn 305 312 9130 8590 10100 9740 10600

Mo < 2 < 2 < 2 < 2 < 2 < 2 < 2

Nb < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2

Nd 0.20 0.28 9.17 9.29 7.35 8.48 8.03

Ni 1.0 1.1 15.5 14.6 16.2 15.4 16.7

P <10 <10 <10 <10 <10 <10 <10

Pb 17.1 18.6 829 1010 654 917 675

Pr 0.05 0.08 2.39 2.46 1.97 2.24 2.05

Rb 0.62 0.64 2.69 2.56 2.72 2.64 2.88

Sb <0.3 <0.3 <0.3 <0.3 <0.3 <0.3 <0.3

Sc < 0.6 0.6 1.0 1.0 1.0 1.0 0.9

Se < 1 < 1 1 < 1 < 1 < 1 < 1

Sm 0.02 0.05 1.56 1.68 1.16 1.40 1.19

Sr 59.5 58.7 474 461 508 503 538

Ta 0.1 < 0.02 0.02 < 0.02 0.02 < 0.02 < 0.02

Tb 0.005 0.007 0.23 0.24 0.18 0.20 0.18

Th < 0.2 < 0.2 < 0.2 0.27 < 0.2 0.25 < 0.2

Ti < 0.5 0.5 2.5 2.5 2.6 2.4 2.8

Tl <0.1 <0.1 0.1 <0.1 0.1 <0.1 0.1

Tm < 0.005 < 0.005 0.056 0.056 0.04 0.05 0.04

U < 0.1 < 0.1 0.1 0.14 < 0.1 < 0.1 < 0.1

V <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5

W < 0.5 < 0.5 < 0.5 < 0.5 < 0.5 < 0.5 < 0.5

Y 0.14 0.18 6.29 6.67 4.93 5.68 5.09

Yb < 0.005 0.009 0.29 0.32 0.21 0.28 0.20

Zn 752 776 24100 23500 24100 23500 25200

Zr < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2
Appendix 4. Results of ICP–MS analyses.—Continued

[mg/L, micrograms per liter; EB,equipment blank; FA, filtered, acidified; –R (appended to sample name), replicate sample; RA, unfiltered, acidified]

Constituent 

(mg/L)

Sample and treatment

EC–MSTD1–02R EC–MSTD1–03 EC–MSTD1–03 EC–MSTD1–03R EC–MSTD1–03R EC–MSTD1–04 EC–MSTD1–04

RA FA RA FA RA FA RA

Ag <1 1.2 1.3 1.2 1.4 <1 <1

Al 662 405 1020 413 1020 23.4 255

As 1 <1 1 <1 1 <1 1

Ba 13.4 14.3 13.9 14.5 13.7 13.9 14.3

Be 1.0 1.3 1.5 1.2 1.4 0.4 0.5

Bi < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2

Cd 147 155 150 156 149 132 132

Ce 13.5 17.5 18.8 17.6 19.0 4.50 6.60

Co 15.2 15.7 14.9 15.7 14.8 13.8 14.4

Cr <1 <1 <1 <1 <1 <1 <1

Cs 0.47 0.49 0.46 0.48 0.45 0.50 0.54

Cu 262 357 389 364 370 82.6 138

Dy 1.04 1.40 1.60 1.40 1.66 0.22 0.46

Er 0.45 0.57 0.65 0.58 0.66 0.093 0.2

Eu 0.35 0.45 0.51 0.45 0.52 0.068 0.16

Ga 0.26 0.28 0.29 0.28 0.28 0.34 0.60

Gd 1.57 2.13 2.37 2.19 2.32 0.38 0.68

Ge < 0.05 < 0.05 < 0.05 < 0.05 < 0.05 < 0.05 < 0.05

Ho 0.18 0.25 0.27 0.24 0.27 0.04 0.076

K 870 940 860 940 870 1090 1320

La 10.9 15.6 15.6 15.5 16.0 4.08 4.99

Li 16.0 15.6 15.4 15.8 15.3 17.2 15.4

Lu < 0.1 < 0.1 < 0.1 < 0.1 < 0.1 < 0.1 < 0.1

Mn 9710 9440 9180 9630 9300 10600 10700

Mo < 2 < 2 < 2 < 2 < 2 < 2 < 2

Nb 0.42 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2

Nd 8.53 11.5 12.1 11.4 12.4 2.08 3.51

Ni 15.9 18.4 17.3 18.4 17.2 14.4 14.9

P <10 <10 <10 <10 <10 <10 10

Pb 923 1000 1450 1010 1470 101 320

Pr 2.27 3.04 3.26 3.04 3.28 0.62 0.98

Rb 2.69 2.77 2.68 2.83 2.68 2.97 2.98

Sb 0.31 <0.3 <0.3 <0.3 <0.3 <0.3 <0.3

Sc 1.0 1.1 1.0 1.1 1.0 < 0.6 0.9

Se < 1 1 < 1 < 1 < 1 1.1 1.8

Sm 1.53 1.86 2.14 1.86 2.16 0.28 0.59

Sr 504 470 473 478 477 674 670

Ta 0.06 < 0.02 < 0.02 < 0.02 < 0.02 < 0.02 < 0.02

Tb 0.21 0.27 0.30 0.28 0.31 0.05 0.093

Th 0.24 < 0.2 0.37 < 0.2 0.39 < 0.2 0.2

Ti 2.5 2.8 2.3 2.6 2.3 4.1 5.7

Tl 0.1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1

Tm 0.05 0.063 0.073 0.062 0.074 0.009 0.02

U 0.1 < 0.1 0.14 < 0.1 0.14 < 0.1 < 0.1

V <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5

W < 0.5 < 0.5 < 0.5 < 0.5 < 0.5 < 0.5 < 0.5

Y 5.63 7.29 8.07 7.4 8.03 1.97 2.91

Yb 0.28 0.31 0.40 0.34 0.43 0.05 0.12

Zn 23700 25100 24600 25200 24300 25000 24700

Zr < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2

Appendix 4 125
126 Hydrogeochemical Investigation of the Standard Mine Vicinity, Upper Elk Creek Basin, Colorado

Appendix 4. Results of ICP–MS analyses.—Continued

[mg/L, micrograms per liter; EB,equipment blank; FA, filtered, acidified; –R (appended to sample name), replicate sample; RA, unfiltered, acidified]

Constituent 

(mg/L)

Sample and treatment

EC–MSTD1–05 EC–MSTD1–05 EC–MSTD1–06 EC–MSTD1–06 EC–MSTD1–07 EC–MSTD1–07 EC–MSTD1–08 EC–MSTD1–08

FA RA FA RA FA RA FA RA

Ag <1 <1 1.5 <1 1.0 1.2 <1 1.1

Al 26.0 580 1550 1910 1010 1170 987 990

As <1 2 <1 3.7 <1 2 <1 1

Ba 14.0 13.8 15.7 24.5 15.2 14.8 15.5 14.5

Be 0.4 0.7 1.8 1.6 1.4 1.2 1.6 1.5

Bi < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2

Cd 138 134 141 133 145 139 132 128

Ce 7.27 11.0 23.4 22.8 18.7 18.4 16.9 16.1

Co 14.2 14.4 14.5 14.1 15.8 15.8 15.5 15.8

Cr <1 <1 <1 <1 <1 <1 <1 <1

Cs 0.54 0.54 0.41 0.44 0.42 0.40 0.36 0.36

Cu 122 209 576 577 428 443 801 813

Dy 0.38 0.87 2.12 2.10 1.57 1.53 1.32 1.24

Er 0.17 0.37 0.87 0.83 0.68 0.67 0.54 0.51

Eu 0.12 0.30 0.71 0.68 0.51 0.51 0.46 0.44

Ga 0.34 0.68 0.40 0.32 0.39 0.59 0.37 0.49

Gd 0.65 1.27 3.16 3.01 2.28 2.18 1.94 1.75

Ge < 0.05 < 0.05 < 0.05 0.05 < 0.05 < 0.05 < 0.05 < 0.05

Ho 0.070 0.15 0.35 0.34 0.27 0.25 0.22 0.20

K 1110 1310 880 2080 860 1000 690 800

La 6.99 8.50 20.6 19.9 15.5 15.0 11.7 11.2

Li 17.7 16.0 13.6 13.5 12.8 10.8 9.6 7.8

Lu < 0.1 < 0.1 < 0.1 < 0.1 < 0.1 < 0.1 < 0.1 < 0.1

Mn 10300 10200 7740 7470 8680 8570 5840 5780

Mo < 2 < 2 < 2 < 2 < 2 < 2 < 2 < 2

Nb < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2

Nd 3.65 6.69 15.8 15.3 11.6 11.1 9.82 9.14

Ni 16.5 16.6 18.2 18.9 16.6 16.4 10.9 11.3

P <10 <10 <10 90 <10 <10 <10 <10

Pb 226 664 1700 1700 1180 1220 1300 1250

Pr 1.11 1.80 4.31 4.10 3.23 3.09 2.66 2.47

Rb 3.02 3.09 2.44 2.98 2.49 2.46 2.04 2.02

Sb <0.3 <0.3 <0.3 <0.3 <0.3 <0.3 <0.3 <0.3

Sc < 0.6 1.0 0.8 0.8 0.6 0.9 < 0.6 0.9

Se 1.5 2.0 1.4 1.4 1.4 2.1 1.3 2.0

Sm 0.50 1.23 2.79 2.75 1.99 1.90 1.71 1.66

Sr 677 655 433 410 422 399 296 277

Ta < 0.02 < 0.02 < 0.02 0.04 < 0.02 < 0.02 < 0.02 < 0.02

Tb 0.081 0.18 0.43 0.42 0.32 0.30 0.26 0.25

Th < 0.2 0.29 0.23 0.79 < 0.2 0.58 0.46 0.46

Ti 4.1 6.3 3.1 4.3 3.1 4.2 2.4 3.2

Tl <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 0.1 0.1

Tm 0.02 0.04 0.096 0.086 0.073 0.069 0.065 0.060

U < 0.1 0.13 0.21 0.21 0.15 0.17 0.25 0.24

V <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5

W < 0.5 < 0.5 < 0.5 < 0.5 < 0.5 < 0.5 < 0.5 < 0.5

Y 3.07 4.72 11.3 10.9 8.72 8.26 6.95 6.38

Yb 0.08 0.21 0.56 0.51 0.39 0.40 0.39 0.32

Zn 26300 25200 24000 22800 24500 23500 20400 19300

Zr < 0.2 < 0.2 < 0.2 0.4 < 0.2 < 0.2 < 0.2 < 0.2
Appendix 4. Results of ICP–MS analyses.—Continued

[mg/L, micrograms per liter; EB,equipment blank; FA, filtered, acidified; –R (appended to sample name), replicate sample; RA, unfiltered, acidified]

Constituent 

(mg/L)

Sample and treatment

EC–MSTD1–09 EC–MSTD1–09 EC–MSTDL31–01 EC–MSTDL31–01 EC–MSTDL32–01 EC–MSTDL32–01

FA RA FA RA FA RA

Ag <1 1.2 <1 1.1 <1 2.2

Al 830 838 1110 1120 736 636

As <1 1 <1 <1 <1 <1

Ba 14.2 14.3 21.4 22.8 9.96 9.46

Be 1.4 1.4 1.5 1.5 1.3 1.2

Bi < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2

Cd 121 115 34.8 36.2 112 106

Ce 13.8 13.2 20.3 21.7 23.1 22.9

Co 14.0 13.7 4.12 4.13 8.94 8.36

Cr <1 <1 <1 <1 <1 <1

Cs 0.36 0.36 0.35 0.40 0.42 0.41

Cu 609 618 340 339 1670 1610

Dy 1.12 1.07 1.00 1.04 0.66 0.64

Er 0.49 0.42 0.42 0.42 0.28 0.27

Eu 0.40 0.37 0.43 0.46 0.32 0.31

Ga 0.29 0.44 0.2 0.2 0.2 0.2

Gd 1.63 1.52 1.60 1.68 1.16 1.14

Ge < 0.05 < 0.05 < 0.05 < 0.05 < 0.05 < 0.05

Ho 0.19 0.18 0.16 0.17 0.10 0.098

K 690 830 560 570 450 410

La 10.0 9.70 11.5 12.3 12.8 12.8

Li 9.8 8.3 6.0 6.1 5.0 4.1

Lu < 0.1 < 0.1 < 0.1 < 0.1 < 0.1 < 0.1

Mn 5620 5500 1560 1570 989 921

Mo < 2 < 2 < 2 < 2 < 2 < 2

Nb < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2

Nd 8.43 7.74 9.95 10.4 9.73 9.26

Ni 10.8 10.5 5.3 5.2 5.2 4.9

P <10 <10 <10 <10 <10 <10

Pb 1330 1290 1770 1870 2190 2210

Pr 2.26 2.11 2.47 2.63 2.64 2.64

Rb 2.01 1.97 1.56 1.64 1.64 1.62

Sb <0.3 <0.3 <0.3 <0.3 <0.3 0.34

Sc < 0.6 0.9 1.0 0.8 0.9 0.9

Se 1.4 2.3 1.7 1.6 1.1 1.3

Sm 1.47 1.41 1.64 1.79 1.41 1.43

Sr 306 293 74.7 76.8 139 133

Ta < 0.02 < 0.02 0.04 < 0.02 < 0.02 < 0.02

Tb 0.22 0.21 0.20 0.22 0.16 0.14

Th 0.35 0.36 < 0.2 < 0.2 0.57 0.59

Ti 2.3 3.7 0.7 0.8 1.2 1.3

Tl <0.1 <0.1 <0.1 <0.1 0.2 0.2

Tm 0.053 0.05 0.05 0.05 0.03 0.03

U 0.21 0.19 0.1 0.11 0.36 0.32

V <0.5 <0.5 <0.5 <0.5 <0.5 <0.5

W < 0.5 < 0.5 < 0.5 < 0.5 < 0.5 < 0.5

Y 6.08 5.62 4.16 4.28 2.62 2.48

Yb 0.32 0.31 0.26 0.26 0.17 0.17

Zn 18300 17200 5340 5340 7700 7200

Zr < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2

Appendix 4 127
128 Hydrogeochemical Investigation of the Standard Mine Vicinity, Upper Elk Creek Basin, Colorado

Appendix 4. Results of ICP–MS analyses.—Continued

[mg/L, micrograms per liter; EB,equipment blank; FA, filtered, acidified; –R (appended to sample name), replicate sample; RA, unfiltered, acidified]

Constituent 

(mg/L)

Sample and treatment

EC–MSTDL33–01 EC–MSTDL33–01 EC–MSTDL34–01 EC–MSTDL34–01 EC–MSTDL35–01 EC–MSTDL35–01 EC–M11600–01

FA RA FA RA FA RA FA

Ag <1 <1 <1 <1 <1 <1 <1

Al <2 10.2 4.5 406 14.1 16.7 15.2

As <1 <1 <1 <1 <1 <1 <1

Ba 5.83 6.25 15.6 16.9 13.0 12.2 14.6

Be 0.05 0.1 0.07 0.4 0.5 0.5 0.7

Bi < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2

Cd 7.27 7.75 21.8 23.1 22.1 20.9 24.5

Ce 0.09 0.23 0.09 0.93 0.70 0.70 0.48

Co 0.32 0.36 0.74 0.84 1.44 1.44 3.12

Cr <1 <1 <1 <1 <1 <1 <1

Cs 0.22 0.25 0.22 0.27 0.46 0.43 0.40

Cu 111 148 53.6 187 432 412 1.6

Dy 0.03 0.04 0.006 0.10 0.16 0.16 0.04

Er 0.02 0.02 < 0.005 0.05 0.084 0.083 0.02

Eu 0.007 0.02 < 0.005 0.04 0.04 0.04 0.01

Ga < 0.05 < 0.05 < 0.05 < 0.05 < 0.05 < 0.05 0.07

Gd 0.03 0.059 0.01 0.17 0.21 0.19 0.057

Ge < 0.05 < 0.05 < 0.05 < 0.05 < 0.05 < 0.05 < 0.05

Ho 0.006 0.01 < 0.005 0.02 0.03 0.03 0.008

K 420 420 570 620 760 700 720

La 0.20 0.32 0.16 0.73 1.00 1.01 0.53

Li 4.1 4.8 10.6 10.6 17.1 15.6 14.2

Lu < 0.1 < 0.1 < 0.1 < 0.1 < 0.1 < 0.1 < 0.1

Mn 13.3 17.4 236 259 211 199 2270

Mo < 2 < 2 < 2 < 2 < 2 < 2 < 2

Nb < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2

Nd 0.17 0.29 0.06 0.82 0.81 0.80 0.26

Ni 0.8 0.8 2.6 2.6 7.3 6.8 2.6

P <10 <10 <10 10 <10 <10 <10

Pb 94.7 278 51.8 360 149 146 14.2

Pr 0.04 0.07 0.02 0.18 0.20 0.19 0.06

Rb 0.97 0.99 1.41 1.62 2.00 1.86 2.04

Sb 0.34 0.42 <0.3 0.40 <0.3 <0.3 <0.3

Sc 0.8 0.8 0.7 1.0 0.8 0.9 1.2

Se < 1 1.2 1.1 1.2 25.2 23.4 < 1

Sm 0.02 0.05 < 0.01 0.15 0.13 0.13 0.04

Sr 132 133 227 230 393 368 170

Ta 0.05 < 0.02 < 0.02 < 0.02 0.04 < 0.02 0.03

Tb 0.005 0.008 < 0.005 0.02 0.03 0.03 0.007

Th < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2

Ti < 0.5 0.5 0.6 0.9 1.1 1.0 1.0

Tl <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1

Tm < 0.005 < 0.005 < 0.005 0.007 0.009 0.009 < 0.005

U < 0.1 < 0.1 < 0.1 < 0.1 < 0.1 < 0.1 < 0.1

V <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5

W < 0.5 < 0.5 < 0.5 < 0.5 < 0.5 < 0.5 < 0.5

Y 0.37 0.49 0.08 0.60 1.44 1.40 0.50

Yb 0.01 0.01 < 0.005 0.03 0.04 0.05 0.01

Zn 1070 1080 1980 2110 2960 2760 3100

Zr < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2
Appendix 4. Results of ICP–MS analyses.—Continued

[mg/L, micrograms per liter; EB,equipment blank; FA, filtered, acidified; –R (appended to sample name), replicate sample; RA, unfiltered, acidified]

Constituent 

(mg/L)

Sample and treatment

EC–M11600–01 EC–M116001–01 EC–M116001–01 EC–M116002–01 EC–M116002–01 EC–M11400B–01 EC–M11400B–01

RA FA RA FA RA FA RA

Ag <1 <1 <1 <1 <1 <1 <1

Al 107 <2 <2 <2 8.9 27.6 170

As <1 1 1 <1 <1 <1 <1

Ba 14.6 12.6 11.7 10.7 10.2 13.1 13.3

Be 0.8 0.5 0.4 0.09 0.1 0.08 0.1

Bi < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2

Cd 24.1 0.08 0.11 3.46 3.50 17.1 16.7

Ce 1.12 0.51 0.58 0.12 0.34 0.59 1.30

Co 3.05 2.72 2.52 0.92 0.91 0.75 0.84

Cr <1 <1 <1 <1 <1 <1 <1

Cs 0.46 0.31 0.29 0.43 0.42 0.14 0.21

Cu 5.4 <0.5 0.95 1.6 3.9 83.4 116

Dy 0.14 0.13 0.14 0.01 0.03 0.070 0.17

Er 0.073 0.072 0.087 0.006 0.02 0.04 0.092

Eu 0.04 0.03 0.03 < 0.005 0.01 0.02 0.057

Ga 0.08 0.08 0.08 < 0.05 < 0.05 < 0.05 < 0.05

Gd 0.18 0.13 0.15 0.02 0.04 0.093 0.21

Ge < 0.05 < 0.05 < 0.05 < 0.05 < 0.05 < 0.05 < 0.05

Ho 0.03 0.03 0.03 < 0.005 0.007 0.01 0.03

K 680 640 580 630 560 330 330

La 0.82 0.27 0.31 0.08 0.18 0.38 0.62

Li 13.9 17.7 16.8 14.0 13.3 1.0 1.7

Lu < 0.1 < 0.1 < 0.1 < 0.1 < 0.1 < 0.1 < 0.1

Mn 2070 4380 4160 1390 1330 331 373

Mo < 2 < 2 < 2 < 2 < 2 < 2 < 2

Nb < 0.2 < 0.2 < 0.2 0.54 < 0.2 < 0.2 < 0.2

Nd 0.75 0.35 0.41 0.07 0.18 0.37 0.85

Ni 2.4 2.1 2.0 0.4 <0.4 0.7 0.6

P 10 <10 <10 <10 <10 <10 <10

Pb 196 1.2 0.85 2.8 44.0 480 1100

Pr 0.18 0.07 0.08 0.02 0.04 0.09 0.20

Rb 2.11 1.48 1.4 1.25 1.20 0.72 0.85

Sb 0.58 <0.3 <0.3 0.32 <0.3 <0.3 <0.3

Sc 1.2 0.8 0.8 1.0 1.1 < 0.6 0.6

Se < 1 < 1 < 1 < 1 < 1 < 1 < 1

Sm 0.14 0.07 0.09 < 0.01 0.04 0.07 0.20

Sr 162 207 200 224 218 71.6 69.1

Ta 0.08 0.04 < 0.02 0.21 0.07 0.08 < 0.02

Tb 0.03 0.02 0.02 < 0.005 0.006 0.01 0.03

Th < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 0.22

Ti 1.2 1.2 1.0 0.8 0.7 < 0.5 1.0

Tl <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1

Tm 0.008 0.01 0.009 < 0.005 < 0.005 0.005 0.01

U < 0.1 < 0.1 < 0.1 < 0.1 < 0.1 < 0.1 0.14

V <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5

W < 0.5 < 0.5 < 0.5 < 0.5 < 0.5 < 0.5 < 0.5

Y 0.92 1.12 1.29 0.18 0.32 0.43 0.78

Yb 0.04 0.06 0.06 0.008 0.009 0.03 0.09

Zn 2890 2340 2260 556 544 3060 2950

Zr 0.3 < 0.2 < 0.2 0.2 0.3 < 0.2 < 0.2

Appendix 4 129
130 Hydrogeochemical Investigation of the Standard Mine Vicinity, Upper Elk Creek Basin, Colorado

Appendix 4. Results of ICP–MS analyses.—Continued

[mg/L, micrograms per liter; EB,equipment blank; FA, filtered, acidified; –R (appended to sample name), replicate sample; RA, unfiltered, acidified]

Constituent 

(mg/L)

Sample and treatment

EC–M11400B–01R EC–M11400B–01R EB–01 EB–01 EB–02 EB–02 EB–03 EB–03

FA RA FA RA FA RA FA RA

Ag <1 <1 <1 <1 <1 <1 <1 <1

Al 28.4 90.1 <2 <2 2.4 <2 <2 <2

As <1 <1 <1 <1 <1 <1 <1 <1

Ba 12.8 13.0 <0.2 <0.2 <0.2 <0.2 <0.2 <0.2

Be 0.1 0.09 <0.05 <0.05 <0.05 <0.05 <0.05 <0.05

Bi < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2

Cd 16.8 16.7 <0.02 <0.02 <0.02 <0.02 <0.02 <0.02

Ce 0.60 1.00 < 0.01 < 0.01 < 0.01 < 0.01 < 0.01 0.01

Co 0.73 0.79 <0.02 <0.02 <0.02 <0.02 <0.02 <0.02

Cr <1 <1 <1 <1 <1 <1 <1 <1

Cs 0.14 0.17 < 0.02 < 0.02 < 0.02 < 0.02 < 0.02 < 0.02

Cu 85.2 102 <0.5 <0.5 <0.5 0.71 <0.5 0.5

Dy 0.075 0.11 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005

Er 0.04 0.063 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005

Eu 0.02 0.04 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005

Ga < 0.05 < 0.05 < 0.05 < 0.05 < 0.05 < 0.05 < 0.05 < 0.05

Gd 0.091 0.15 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005

Ge < 0.05 < 0.05 < 0.05 < 0.05 < 0.05 < 0.05 < 0.05 < 0.05

Ho 0.02 0.02 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005

K 320 330 <30 <30 <30 <30 <30 <30

La 0.37 0.49 < 0.01 < 0.01 < 0.01 < 0.01 < 0.01 < 0.01

Li 0.9 1.3 0.9 < 0.1 0.4 0.6 0.2 0.2

Lu < 0.1 < 0.1 < 0.1 < 0.1 < 0.1 < 0.1 < 0.1 < 0.1

Mn 327 363 <0.2 <0.2 0.5 <0.2 <0.2 <0.2

Mo < 2 < 2 < 2 < 2 < 2 < 2 < 2 < 2

Nb < 0.2 < 0.2 < 0.2 0.31 < 0.2 < 0.2 < 0.2 < 0.2

Nd 0.38 0.59 < 0.01 < 0.01 < 0.01 < 0.01 < 0.01 < 0.01

Ni 0.7 0.7 <0.4 <0.4 <0.4 <0.4 <0.4 <0.4

P <10 <10 <10 <10 <10 <10 <10 <10

Pb 486 830 <0.05 <0.05 0.4 <0.05 <0.05 43.0

Pr 0.09 0.14 < 0.01 < 0.01 < 0.01 < 0.01 < 0.01 < 0.01

Rb 0.72 0.77 < 0.01 < 0.01 < 0.01 < 0.01 < 0.01 < 0.01

Sb <0.3 <0.3 0.44 <0.3 <0.3 <0.3 <0.3 <0.3

Sc < 0.6 < 0.6 < 0.6 < 0.6 < 0.6 < 0.6 < 0.6 < 0.6

Se < 1 < 1 < 1 < 1 < 1 < 1 < 1 < 1

Sm 0.06 0.14 < 0.01 < 0.01 < 0.01 < 0.01 < 0.01 < 0.01

Sr 71.4 69.0 < 0.5 < 0.5 < 0.5 < 0.5 < 0.5 < 0.5

Ta 0.07 < 0.02 0.2 0.05 0.2 0.02 0.1 < 0.02

Tb 0.01 0.02 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005

Th < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2

Ti < 0.5 0.5 < 0.5 < 0.5 < 0.5 < 0.5 < 0.5 < 0.5

Tl <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1

Tm < 0.005 0.008 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005

U < 0.1 < 0.1 < 0.1 < 0.1 < 0.1 < 0.1 < 0.1 < 0.1

V <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5

W < 0.5 < 0.5 0.5 < 0.5 < 0.5 < 0.5 < 0.5 < 0.5

Y 0.44 0.56 < 0.01 < 0.01 < 0.01 < 0.01 < 0.01 < 0.01

Yb 0.03 0.05 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005

Zn 3060 3020 0.6 <0.5 1.4 1.0 1.0 0.7

Zr < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2 < 0.2
Appendix 4. Results of ICP–MS analyses.—Continued

[mg/L, micrograms per liter; EB,equipment blank; FA, filtered, acidified; –R (appended to sample name), 

replicate sample; RA, unfiltered, acidified]

Constituent 

(mg/L)

Sample and treatment

EB–04 EB–04 EB–05 EB–05

FA RA FA RA

Ag <1 <1 <1 <1

Al <2 <2 <2 <2

As <1 <1 <1 <1

Ba <0.2 <0.2 <0.2 <0.2

Be <0.05 <0.05 <0.05 <0.05

Bi < 0.2 < 0.2 < 0.2 < 0.2

Cd <0.02 <0.02 <0.02 <0.02

Ce < 0.01 < 0.01 < 0.01 < 0.01

Co <0.02 <0.02 <0.02 <0.02

Cr <1 <1 <1 <1

Cs < 0.02 < 0.02 < 0.02 < 0.02

Cu <0.5 0.51 < 0.5 < 0.5

Dy < 0.005 < 0.005 < 0.005 < 0.005

Er < 0.005 < 0.005 < 0.005 < 0.005

Eu < 0.005 < 0.005 < 0.005 < 0.005

Ga < 0.05 < 0.05 < 0.05 < 0.05

Gd < 0.005 < 0.005 < 0.005 < 0.005

Ge < 0.05 < 0.05 < 0.05 < 0.05

Ho < 0.005 < 0.005 < 0.005 < 0.005

K <30 <30 <30 <30

La < 0.01 < 0.01 < 0.01 < 0.01

Li < 0.1 < 0.1 0.2 < 0.1

Lu < 0.1 < 0.1 < 0.1 < 0.1

Mn <0.2 < 0.2 <0.2 < 0.2

Mo < 2 < 2 < 2 < 2

Nb < 0.2 < 0.2 < 0.2 < 0.2

Nd < 0.01 < 0.01 < 0.01 < 0.01

Ni <0.4 < 0.4 < 0.4 < 0.4

P <10 <10 <10 <10

Pb <0.05 0.05 0.08 0.08

Pr < 0.01 < 0.01 < 0.01 < 0.01

Rb < 0.01 < 0.01 < 0.01 < 0.01

Sb <0.3 < 0.3 < 0.3 < 0.3

Sc < 0.6 < 0.6 < 0.6 < 0.6

Se < 1 < 1 < 1 < 1

Sm < 0.01 < 0.01 < 0.01 < 0.01

Sr < 0.5 < 0.5 < 0.5 < 0.5

Ta < 0.02 < 0.02 < 0.02 < 0.02

Tb < 0.005 < 0.005 < 0.005 < 0.005

Th < 0.2 < 0.2 < 0.2 < 0.2

Ti < 0.5 < 0.5 < 0.5 < 0.5

Tl <0.1 <0.1 <0.1 <0.1

Tm < 0.005 < 0.005 < 0.005 < 0.005

U < 0.1 < 0.1 < 0.1 < 0.1

V <0.5 <0.5 <0.5 <0.5

W < 0.5 < 0.5 < 0.5 < 0.5

Y < 0.01 < 0.01 < 0.01 < 0.01

Yb < 0.005 < 0.005 < 0.005 < 0.005

Zn <0.5 0.6 0.5 1.4

Zr < 0.2 < 0.2 < 0.2 < 0.2

Appendix 4 131
Manning and others—Hydrogeochemical Investigation, Standard Mine Vicinity, Colorado—Scientific Investigations Report 2007–5265

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