U.S. Department of the Interior

U.S. Geological Survey

Scientific Investigations Report 2015–5147

Prepared in cooperation with the Bureau of Land Management, White River Field Office

Characterization of Hydrology and Water Quality of Piceance 

Creek in the Alkali Flat Area, Rio Blanco County, Colorado, 

March 2012
Front Cover. Hydrologist measuring streamflow in Piceance Creek, Alkali Flat area, Rio Blanco County, Colorado. Photograph by 

Judith Thomas, U.S. Geological Survey, March 14, 2012.

Back Cover. Left, Spring, Alkali Flat area, Rio Blanco County, Colorado. Photograph by Jennifer Moore, U.S. Geological Survey, 

February 24, 2012. Right, Research hydrologist sampling springs, Alkali Flat area, Rio Blanco County, Colorado. Photograph by 

Judith Thomas, U.S. Geological Survey March 27, 2012.
Characterization of Hydrology and Water 

Quality of Piceance Creek in the Alkali 

Flat Area, Rio Blanco County, Colorado, 

March 2012

By Judith C. Thomas

Scientific Investigations Report 2015–5147

U.S. Department of the Interior

U.S. Geological Survey

Prepared in cooperation with the Bureau of Land Management, White River Field Office
U.S. Department of the Interior

SALLY JEWELL, Secretary

U.S. Geological Survey

Suzette M. Kimball, Acting Director

U.S. Geological Survey, Reston, Virginia: 2015

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Suggested citation:

Thomas, J.C., 2015, Characterization of hydrology and water quality of Piceance Creek in the Alkali Flat area, 

Rio Blanco County, Colorado, March 2012: U.S. Geological Survey Scientific Investigations Report 2015–5147, 23 p., 

http://dx.doi.org/10.3133/sir20155147.

ISSN 2328-0328 (online)
iii

Contents

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

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

Purpose and Scope ..............................................................................................................................2

Description of Study Area ...................................................................................................................2

Methods of Data Collection .........................................................................................................................2

Characterization of Surface-Water Hydrology .......................................................................................11

Characterization of Surface-Water Quality.............................................................................................14

Sources of Recharge to Springs and Spring Contribution to Piceance Creek..................................17

Summary........................................................................................................................................................22

References Cited..........................................................................................................................................23

Figures

1. Map showing location of study area, Piceance Creek in the Alkali Flat area, 

Rio Blanco County, Colorado ......................................................................................................3

2. Annual hydrograph at U.S. Geological Survey streamflow-gaging stations 09306200 

and 09306222 for water year 2012, Piceance Creek in the Alkali Flat area, Rio Blanco

County, Colorado .................................................................................................................................4

3. Map showing location of surface-water and spring-sampling sites sampled during 

March 2012, Piceance Creek in the Alkali Flat area, Rio Blanco County, Colorado..........5

4. A, Photograph of drive point end showing perforation and hammered end. 

B, Photograph of deployed drive point in spring (site PCSP3) with tubing and 

peristaltic pump ..........................................................................................................................12

5–10. Graphs showing:

 5. Instantaneous streamflow measurements and continuous streamflow from 

U.S. Geological Survey gaging station within the study reach, Piceance Creek 

in the Alkali Flat area, Rio Blanco County, Colorado, February 22–29, 2012..............13

 6. Instantaneous streamflow measurements and continuous streamflow from

U.S. Geological Survey gaging station within the study reach, Piceance Creek 

in the Alkali Flat area, Rio Blanco County, Colorado, March 14, 2012 ........................13

 7. Instantaneous streamflow measurements along the study reach, Piceance 

Creek in the Alkali Flat area, Rio Blanco County, Colorado, February and 

March 2012 ...........................................................................................................................14

 8. Selected dissolved-cation concentrations March 14, 2012, Piceance Creek 

in the Alkali Flat area, Rio Blanco County, Colorado .....................................................15

 9. Selected dissolved-anion concentrations March 14, 2012, Piceance Creek 

in the Alkali Flat area, Rio Blanco County, Colorado .....................................................16

 10. Selected dissolved trace-element concentrations March 14, 2012, Piceance 

Creek in the Alkali Flat area, Rio Blanco County, Colorado..........................................17

11. Trilinear diagram showing major-ion chemistry of water from Piceance Creek 

and spring samples, Piceance Creek in the Alkali Flat area, Rio Blanco County, 

Colorado .......................................................................................................................................18
iv

12–14. Graphs showing:

 12. Stable isotopic composition of water (delta oxygen-18, δ18O[H2O], and 

deuterium/protium -, δ2H[H2O]) from springs in the Alkali Flat area compared 

to groundwater from the Green River Formation, snow from Grand Mesa, 

Colorado, and produced waters from the Mesaverde Group in Piceance 

Basin, western Colorado....................................................................................................19

 13. Selected dissolve-cation and dissolved-anion loads for March 14, 2012, 

Piceance Creek in the Alkali Flat area, Rio Blanco County, Colorado........................20

 14. Selected dissolved trace-element loads for March 14, 2012, Piceance Creek 

in the Alkali Flat area, Rio Blanco County, Colorado .....................................................21

Tables

1. Surface-water quality data at select sites on Piceance Creek, comparing waterquality data from December 2000 to December 2010, Piceance Creek in the 

Alkali Flat area, Rio Blanco County, Colorado..........................................................................6

2. Water-quality data and loads at surface-water and spring-sampling sites in the 

Alkali Flat area, Rio Blanco County, Colorado, March 2012...................................................7

Conversion Factors

Inch/Pound to SI

Multiply By To obtain

Length

inch (in.) 2.54 centimeter (cm)

inch (in.) 25.4 millimeter (mm)

foot (ft) 0.3048 meter (m)

mile (mi) 1.609 kilometer (km)

mile, nautical (nmi) 1.852 kilometer (km)

yard (yd) 0.9144 meter (m)

Area

square foot (ft2) 929.0 square centimeter (cm2)

square foot (ft2) 0.09290 square meter (m2)

square mile (mi2) 259.0 hectare (ha)

square mile (mi2) 2.590 square kilometer (km2) 

Volume

cubic foot (ft3) 0.02832 cubic meter (m3)

acre-foot (acre-ft) 0.001233 cubic hectometer (hm3)

Flow rate

cubic foot per second (ft3/s) 0.02832 cubic meter per second (m3/s)

Load

pounds per day 0.4536 kilograms per day

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).

Specific conductance was given in microsiemens per centimeter at 25 degrees Celsius (μS/cm).

Altitude, as used in this report, refers to distance above the vertical datum.
Characterization of Hydrology and Water Quality of 

Piceance Creek in the Alkali Flat Area, Rio Blanco County, 

Colorado, March 2012

By Judith C. Thomas

Loading profiles were used to further refine areas of 

spring and groundwater input and streamflow gains and losses. 

Although there was a minor gain in streamflow from sites 

PC21543 to PC21816 (58 to 59 cubic feet per second (ft3/s) 

during March 2014), the observed increase in dissolved solids 

load indicated groundwater contribution to Piceance Creek 

between these two sites. From sites PC22737 to PC22980, 

dissolved solids load decreased, which was not observed 

in concentration profiles and indicated that streamflow loss 

occurred between these two sites. Barium, boron, lithium, 

and strontium loads showed similar patterns to that of the 

major ions along the study reach and indicated similar areas 

of groundwater gain and loss. Boron and lithium load were not 

observed to decrease in a similar pattern to that of barium and 

strontium load which would suggest the contribution to the 

stream from sources with similar chemistry to that of spring 

sites PCSP2 through PCSP5. Sodium, chloride, and bicarbonate loads increased and decreased along the study reach in 

a pattern similar to that of dissolved solids load. A chemical 

mass balance was used to estimate the amount of groundwater 

and (or) spring water that contributed to the observed changes 

in water quality along Piceance Creek. This analysis indicated 

only 5 percent spring water would need to reach Piceance 

Creek to result in the observed changes in water quality.

Instantaneous streamflow was measured from 

sites PC20133 to PC23721 during field reconnaissance 

(February 2012) and during synoptic sampling (March 2012). 

During both February and March, the study reach from 

sites PC20133 to PC23721 was a losing reach with net 

losses that ranged from 0.5 ft3/s (February) to 3 ft3/s (March). 

Observed changes in streamflow along the study reach helped 

to depict interactions between groundwater and surface water 

in the Alkali Flat area.

Water-quality samples were collected at five surfacewater sites in December 2010 that were sampled as part of a 

previous USGS study in 2000. Water-quality data collected 

during December 2010 showed no appreciable difference from 

water-quality data collected during December 2000 at the 

five sites.

Abstract

Previous studies by the U.S. Geological Survey identified Alkali Flat as an area of groundwater upwelling, with 

increases in concentrations of total dissolved solids, and 

streamflow loss, but additional study was needed to better 

characterize these observations. The U.S. Geological Survey, 

in cooperation with the Bureau of Land Management, White 

River Field Office, conducted a study to characterize the 

hydrology and water quality of Piceance Creek in the Alkali 

Flat area of Rio Blanco County, Colorado.

Water-quality samples were collected at five springs on 

March 27, 2012, to determine field properties, major ions, 

trace elements, and stable isotopes of water. Major-ion and 

trace-element chemistry indicated that the springs sampled 

as part of this study were likely recharged by the bedrock 

aquifer. Isotopic values for the springs plotted close to that of 

groundwater from the Parachute Creek Member of the Green 

River Formation, and the isotopic values from both of these 

sources are similar to the values for Grand Mesa snow. Based 

on fluoride, lithium, and strontium concentrations, one spring 

appeared to have different source water than the other four 

springs. The spring also had higher concentrations of calcium, 

magnesium, and sulfate relative to the other four springs. 

Trace-element and major-ion data indicate that this spring 

was sourced from the Uinta Formation. It was likely the other 

four springs were primarily sourced from the lower part of 

the Parachute Creek Member of the Green River Formation 

as indicated by low sulfate concentrations and high fluoride, 

lithium, and boron concentrations.

Water-quality samples were collected at 16 surface-waterquality sites on March 14, 2012, to determine field properties, 

major ions, and trace elements. Sodium was the dominant 

cation and concentrations increased steadily from upstream to 

downstream along the study reach. Calcium, magnesium, and 

potassium concentrations remained relatively stable along the 

study reach. Strontium concentrations were relatively stable 

along the study reach, whereas boron and lithium concentrations increased appreciably at site PC22031 and remained 

elevated to the end of the study reach.
2 Characterization of Hydrology and Water Quality of Piceance Creek in the Alkali Flats Area, Colorado

Introduction

Alkali Flat is an area of approximately 0.3 square miles 

(mi2) along the northern end of Piceance Creek, and is situated approximately 4 miles upstream from the confluence of 

Piceance Creek and the White River (fig. 1). Springs and seeps 

occur along Piceance Creek in the Alkali Flat area. Results of 

previous studies (Ortiz, 2002; Taylor, 1987) identified Alkali 

Flat as an area of both groundwater upwelling and streamflow 

loss, and showed that concentrations of dissolved solids in 

Piceance Creek increased in a downstream direction; however, 

additional study would be needed to better understand these 

observations. The U.S. Geological Survey (USGS), in cooperation with the Bureau of Land Management (BLM), White 

River Field Office, conducted a study to further characterize the hydrology and water quality of Piceance Creek in the 

Alkali Flat area.

Purpose and Scope

The purpose of this report is to characterize the 

hydrology of Piceance Creek in the Alkali Flat area and to 

identify areas of streamflow gain and loss. Water quality of 

both springs and Piceance Creek are examined to improve 

understanding of springs’ contribution to the water quality 

of Piceance Creek. Water-quality samples were collected at 

five sites in December 2010 that were sampled as part of a 

previous USGS study (Ortiz, 2002) to understand and identify 

potential changes that may have occurred since 2000. In addition, 16 stream sites and 5 springs were sampled to characterize water quantity and quality in Piceance Creek in the Alkali 

Flat area in March 2012.

Description of Study Area

The study area extends between Piceance Creek at Ryan 

Gulch streamflow-gaging station 09306200 and Piceance 

Creek at White River streamflow-gaging station 09306222 

(fig. 1), but focuses on the Alkali Flat area. Piceance Creek is 

a meandering stream channel incised into Quaternary alluvial 

deposits with steep banks prone to sloughing. In the Alkali 

Flat area, these alluvial deposits are underlain by the Tertiary 

Uinta Formation (Tweto, 1979). The Uinta Formation is a 

gray and yellow-brown marlstone, siltstone, sandstone, and 

tuff which intertongues with the underlying Parachute Creek 

Member of the Tertiary Green River Formation (Taylor, 1987). 

The Parachute Creek Member is composed of dolomitic 

marlstone and shale layers where water bearing layers are 

separated by the Mahogany zone into an upper and lower aquifer (Coffin and others, 1971). A northwest-southeast-trending 

fault zone runs through the Alkali Flat area (Taylor, 1987; 

Verbeek and Grout, 1983) and likely accounts for the numerous springs and seeps in the Alkali Flat area.

Methods of Data Collection

In order to understand streamflow quantity and quality, 

the investigation was conducted under base-flow conditions 

(March) to minimize the influence of irrigation practices 

on streamflow. Under base-flow conditions, streamflow 

increased along the study reach whereas during the irrigation 

season this pattern was less evident (fig. 2). Using a similar 

approach to the previous study by Ortiz, sites were identified by a downstream distance from Piceance Creek at Ryan 

Gulch streamflow-gaging station 09306200 (field site PC0) 

(Ortiz, 2002). Synoptic samples and streamflow measurements were collected between the area just above Alkali Flat, 

which was 12.5 miles downstream from site PC0 to just below 

Alkali Flat, which was 14.7 miles downstream from site PC0. 

In the Alkali Flat area, from sites PC20408 to PC23721, there 

were no perennial streams discharging to Piceance Creek 

(fig. 3).

Water-quality samples were collected at five sites in 

December 2010 that were sampled as part of a previous USGS 

study (Ortiz, 2002) to understand and identify potential changes 

that may have occurred since 2000. Of the five sites, three 

sites were upstream from the Alkali Flat area (sites PC5280, 

PC14789, PC16210), one was within the Alkali Flat area 

(site PC20708), and one was downstream from the Alkali Flat 

area (site PC24787) (fig. 1 and table 1). At these sites, waterquality samples were collected for major ions, trace elements 

(boron, barium, arsenic, and strontium), and streamflow 

measurements and field properties (pH, specific conductance, 

temperature, and alkalinity) were collected (table 1).

Surface-water quality data at select sites on Piceance 

Creek, comparing water-quality data from December 2000 

to December 2010, Piceance Creek in the Alkali Flat area, 

Rio Blanco County, Colorado. Sixteen stream sites and five 

springs were sampled to characterize water quantity and 

quality in Piceance Creek in the Alkali Flat area. The study 

reach and sites were identified during field reconnaissance 

conducted February 2012 (fig. 3). For all sites, photographs 

and location data were collected. Streamflow measurements 

and field properties were collected during reconnaissance. 

Field properties were collected at springs. During reconnaissance, 14 new surface-water sites and 2 existing surface-water 

sites were investigated. Existing sites were defined as those 

sites that have historical data collected at them and new sites 

were defined as having no data collected at them prior to this 

study. The two existing surface-water sites were USGS station 

number 400206108154700 (site PC20708) and USGS station 

number 400306108150000 (site PC23721). Spring sites were 

also identified during reconnaissance, including one existing 

spring site (USGS station number 400216108154000), and 

four new spring sites (table 2).
Methods of Data Collection 3

Figure 1. Location of study area, Piceance Creek in the Alkali Flat area, Rio Blanco County, Colorado.

Study area

Base from Environmental Research Systems Institute 

(ESRI) digital data, 2009, 1:24,000 and 

U.S. Geological Survey digital data, 2010, 1:100,000

Universal Transverse Mercator, Zone 13 North

"

"

"

#

#

Roan Creek

Parachute Creek

Colora do Ri ver

Piceance Creek

Dry Fork Piceance Creek

Willow Creek

Yellow Creek

Douglas Creek

White River

White River

Piceance Creek

Rya n G ulch

Black Sulphur Cr eek

Rifle

Meeker

Rangely

RIO BLANCO COUNTY

GARFIELD COUNTY

MESA COUNTY

09306222

09306200

108°50' 108°19' 107°49'

40°08'

39°38'

!

!

!

!

!

PC5280

PC24787

PC20708

PC16210

PC14789

0 5 10 20 MILES

0 5 10 20 KILOMETERS

EXPLANATION

# U.S. Geological Survey streamflow-

 gaging station

Piceance Basin

! Existing surface-water-quality site 

 and identifier (table 1)

Study area

PC16210

09306200

DENVER

Grand 

Junction

Meeker

COLORADO

Study area

Piceance

Basin

MAP LOCATION

70

139

64

13
4 Characterization of Hydrology and Water Quality of Piceance Creek in the Alkali Flats Area, Colorado

Figure 2. Annual hydrograph at U.S. Geological Survey streamflow-gaging stations 

09306200 and 09306222 for water year 2012 (a water year is the 12-month period October 1 

through September 30 designated by the calendar year in which it ends), Piceance Creek 

in the Alkali Flat area, Rio Blanco County, Colorado.

Synoptic sampling was conducted during March 2012, 

when water-quality samples and streamflow measurements 

were collected at all 16 stream sites. Streamflow measurements were collected at surface-water sites during reconnaissance and during the synoptic sampling (February and 

March 2012, respectively). Streamflow measurements were 

made using standard techniques (Rantz and others, 1982; 

Turnipseed and Sauer, 2010). Measurements were rated by 

the individual making the measurement based on the hydrologic and hydraulic conditions in which the measurements 

were made (Turnipseed and Sauer, 2010). These ratings are 

a means of associating a numeric estimate of the percentage 

of error associated with a measurement, for this study error 

associated with streamflow measurements ranged from 5 to 

8 percent where 5 percent is considered good and 8 percent 

is considered fair. These data were used to further investigate 

areas of suspected streamflow loss in the study reach and to 

determine if streamflow conditions remained constant during 

synoptic sampling.

Synoptic sampling was conducted to provide a spatially 

detailed description of the water quality in Piceance Creek 

by sampling 16 sites in a short period of time. Four staff 

members were located along Piceance Creek and collected 

one water-quality sample and one streamflow measurement 

at each sampling location from upstream to downstream. 

Samples were collected in clean 4-liter plastic containers 

from the centroid of flow. Once samples were collected, 

Bureau of Land Management staff transported samples back 

to the processing vehicle where samples were processed. 

During synoptic sampling in March 2012, field properties 

(temperature, specific conductance, pH, dissolved oxygen, 

and alkalinity) were measured and samples were collected for 

10-01-201111-06-201112-12-2011

01-17-2012

02-22-2012

 03-29-2012

05-04-201206-09-201207-15-201208-20-2012

 09-25-2012

0

5

10

15

20

25

30

35

40

45

50

55

Streamflow, in cubic feet per second

Station 09306222

Station 09306200

 

EXPLANATION

Date

Base flow Irrigation
Methods of Data Collection 5

Figure 3. Location of surface-water and spring-sampling sites sampled during March 2012, Piceance 

Creek in the Alkali Flat area (see fig. 1), Rio Blanco County, Colorado.

0

0 0.1 0.2 0.3 KILOMETER

0.1 0.2 0.3 MILE

Piceance Creek

Flow

Flow

Piceance Creek

Base from The National Map digital data, 2015

Universal Transverse Mercator projection, meters

Zone 13, North American Datum of 1983

PC20708

PC21297

PCSP2

PC21299

PC21543

PC22436

PC20133

PC22737

PCSP5

PC22980

PC20408

PC22031

PC22184

PCSP4

PC21816

PC21128

PC23163

PC23357

PC23721

PCSP1

PCSP3

108°16' 108°15'45"

40°03'15"

40°02'45"

40°02'30"

40°02'15"

40°02'

40°03'

108°15'30" 108°15'15" 108°15' 108°14'45"

EXPLANATION

Study area

Surface-water-sampling site 

 and identifier—Table 2

Spring-sampling site and 

 identifier—Table 2

PC20133

PCSP2

DENVER

Grand 

Junction

Meeker

COLORADO

Study area

Piceance

Basin

MAP LOCATION
6 Characterization of Hydrology and Water Quality of Piceance Creek in the Alkali Flats Area, Colorado

Table 1. Surface-water quality data at select sites on Piceance Creek, comparing water-quality data from December 2000 to December 2010, 

Piceance Creek in the Alkali Flat area, Rio Blanco County, Colorado.

[ID, identifier; --, no data; DD, decimal degrees; ft3/s, cubic feet per second; mg/L, milligram per liter; μS/cm, microsiemens per centimeter; °C, degrees Celsius; 

mg/L as CaCO3, milligrams per liter as calcium carbonate; μg/L, micrograms per liter; E, estimated; <, less than]

Station

number

Field site ID

(see fig. 3

for location)

Date

Sample 

start time 

(24-hour)

Latitude 

(DD)

Longitude 

(DD)

Streamflow

(ft3/s)

pH 

(standard 

units)

Specific 

conductance 

(μS/cm at 

25 °C)

Temperature 

(°C)

395658108170100 PC5280 12/07/2000 0700 39.949 –108.284 -- 8.1 1,590 --

395658108170100 PC5280 12/15/2010 1405 39.949 –108.284 19 8.5 1,520 4.4

395951108145900 PC14789 12/06/2000 1005 39.998 –108.250 -- 8 1,780 --

395951108145900 PC14789 12/15/2010 1305 39.998 –108.250 21 8.5 1,610 3.9

400030108144700 PC16210 12/06/2000 0910 40.008 –108.246 -- 8 1,770 --

400030108144700 PC16210 12/15/2010 1150 40.008 –108.246 21 8.5 1,620 3.8

400206108154700 PC20708 12/06/2000 1030 40.035 –108.263 -- 8 1,730 --

400206108154700 PC20708 12/15/2010 1045 40.035 –108.263 26 8.5 1,650 3.9

400334108150600 PC24787 12/06/2000 0900 40.060 –108.252 -- 7.9 1,950 --

400334108150600 PC24787 12/15/2010 0930 40.060 –108.252 25 8.5 1,880 3.6

Station

number

Calcium, 

dissolved 

(mg/L)

Magnesium, 

dissolved 

(mg/L)

Potassium, 

dissolved 

(mg/L)

Sodium,

dissolved

(mg/L)

Alkalinity 

(mg/L as

CaCO3)

Bromide, 

dissolved

(mg/L)

Chloride, 

dissolved

(mg/L)

Fluoride,

dissolved

(mg/L)

Silica,

dissolved

(mg/L)

395658108170100 88.8 79.4 2.39 175 482 -- 16.8 0.59 16.5

395658108170100 89.4 84.2 2.62 182 463 0.065 18.2 0.73 17.1

395951108145900 79.2 84.9 2.54 203 481 0.1 19.2 0.64 17

395951108145900 85.5 86.5 2.76 205 497 0.072 21.1 0.71 17.3

400030108144700 84.2 87.8 2.53 204 524 0.09 19.1 0.67 16.8

400030108144700 85.9 87.4 2.85 214 512 0.081 20.5 0.75 17.3

400206108154700 81.4 83.1 2.48 200 492 0.09 20.1 0.67 16.8

400206108154700 81.6 83.6 2.7 218 540 0.085 22.5 0.78 17.3

400334108150600 83.3 84.9 2.54 269 592 0.13 33.6 0.86 16.4

400334108150600 82.4 85.3 2.96 297 643 0.076 51.3 0.92 17.3

Station

number

Sulfate,

dissolved

(mg/L)

Aluminum,

dissolved

(μg/L)

Barium,

dissolved

(μg/L)

Iron,

dissolved

(μg/L)

Strontium, 

dissolved

(μg/L)

Zinc, 

dissolved

(μg/L)

Antimony, 

dissolved

(μg/L)

Arsenic, 

dissolved

(μg/L)

Boron, 

dissolved

(μg/L)

395658108170100 419 -- 75.6 E6.3 3,140 2 0.117 E2 170

395658108170100 407 -- 71.5 -- 3,030 -- -- 1.9 178

395951108145900 435 1.2 78.6 <10.0 2,980 1.7 0.183 1.9 186

395951108145900 413 -- 74.2 -- 3,040 -- -- 2 188

400030108144700 425 1.5 79.2 <10.0 3,000 2.4 <0.048 2.4 192

400030108144700 416 -- 78.7 -- 3,130 -- -- 2.1 190

400206108154700 411 1.3 82 <10.0 2,810 2 <0.048 2.2 192

400206108154700 400 -- 86.4 -- 2,910 -- -- 2.2 208

400334108150600 407 1.2 102 <30.0 2,840 1.9 <0.048 2.6 229

400334108150600 399 -- 111 -- 2,900 -- -- 2.2 226
Methods of Data Collection 7

Table 2. Water-quality data and loads at surface-water and spring-sampling sites in the Alkali Flat area, Rio Blanco County, Colorado, 

March 2012.

[ID, identifier; --, no data; DD, decimal degrees; ft3/sec, cubic feet per second; mg/L, milligram per liter; μS/cm, microsiemens per centimeter; mg/L as CaCO3, 

milligrams per liter as calcium carbonate; μg/L, micrograms per liter; <, less than]

Field site ID

(see fig. 3

for location)

Station

number Site type

Distance

downstream from

station 09306200,

in miles

Date

Sample

start

time

Latitude

(DD)

Longitude

(DD)

Streamflow

(ft3/s)

Dissolved

oxygen

(mg/L)

PC20133 400202108153501 Surface water 12.5 03/14/2012 0900 40.034 –108.260 56 --

PC20408 400207108153201 Surface water 12.7 03/14/2012 1030 40.035 –108.259 56 --

PC20708 400206108154700 Surface water 12.9 03/14/2012 1250 40.035 –108.263 57 --

PC21128 400217108153901 Surface water 13.1 03/14/2012 1600 40.038 –108.261 60 9.2

PC21297 400213108153401 Surface water 13.2 03/14/2012 1500 40.037 –108.259 59 9.3

PC21299 400218108153301 Surface water 13.2 03/14/2012 1400 40.038 –108.259 56 9.6

PC21543 400217108152701 Surface water 13.4 03/14/2012 1245 40.038 –108.258 58 9.9

PC21816 400222108152201 Surface water 13.6 03/14/2012 1130 40.039 –108.256 59 10.1

PC22031 400228108152601 Surface water 13.7 03/14/2012 1015 40.041 –108.257 58 10

PC22184 400233108152501 Surface water 13.8 03/14/2012 0845 40.043 –108.257 58 10.1

PC22436 400240108152301 Surface water 13.9 03/14/2012 0905 40.044 –108.256 60 10.5

PC22737 400248108152301 Surface water 14.1 03/14/2012 1010 40.047 –108.256 59 10.8

PC22980 400254108151901 Surface water 14.3 03/14/2012 1105 40.048 –108.255 51 9.6

PC23163 400258108151601 Surface water 14.4 03/14/2012 1335 40.049 –108.254 49 10.8

PC23357 400302108151401 Surface water 14.5 03/14/2012 1235 40.051 –108.254 53 10.6

PC23721 400306108150000 Surface water 14.7 03/14/2012 1450 40.052 –108.250 53 --

PCSP1 400216108154000 Spring -- 03/27/2012 1630 40.038 –108.262 -- <0.5

PCSP2 400217108152801 Spring -- 03/27/2012 1445 40.038 –108.258 -- <0.5

PCSP3 400219108152501 Spring -- 03/27/2012 1045 40.039 –108.257 -- <0.5

PCSP4 400219108152401 Spring -- 03/27/2012 1230 40.039 –108.257 -- <0.5

PCSP5 400220108152301 Spring -- 03/27/2012 1330 40.039 –108.256 -- <0.5

Field site ID

(see fig. 3

for location)

pH 

(standard

units)

Specific

conductance

(μS/cm

at 25 °C)

Temperature

(°C)

Calcium,

dissolved

(mg/L)

Calcium

load

(pounds/day)

Magnesium,

dissolved

(mg/L)

Potassium,

dissolved

(mg/L)

Sodium,

dissolved

(mg/L)

PC20133 -- 1,030 3.9 58.4 17,663 48.2 3.77 106

PC20408 -- 1,040 4.4 59.1 17,836 48.9 3.77 107

PC20708 -- 1,030 6.2 58.8 17,933 48.4 3.86 112

PC21128 8.4 1,030 8.9 58.8 19,132 48.2 3.92 116

PC21297 8.5 1,030 8.2 58.3 18,691 48 3.83 117

PC21299 8.4 1,040 7.4 58.6 17,690 48.5 3.85 121

PC21543 8.4 1,060 6.2 58.8 18,409 48.5 3.87 124

PC21816 8.4 1,080 5.1 59.2 18,822 49 3.84 129

PC22031 8.4 1,100 4.2 58.2 18,253 48.3 3.8 130

PC22184 8 1,080 3.4 57.2 18,030 46.8 3.72 130

PC22436 8.7 1,090 3.3 56.6 18,199 46.9 3.78 133

PC22737 8.8 1,110 4 58.5 18,646 48 3.85 136

PC22980 8.7 1,140 5.2 59.3 16,319 49 3.82 141

PC23163 8.8 1,140 7.8 58.8 15,579 48.3 3.81 142

PC23357 8.8 1,140 6.9 60.2 17,135 49.1 3.9 140

PC23721 8.9 1,130 8.8 58.3 16,648 48 3.84 143

PCSP1 7.6 12,700 14.5 18 -- 52.4 8.62 3,420

PCSP2 7.8 34,000 15.6 8.66 -- 10.5 32.9 11,300

PCSP3 7.5 36,900 14.7 4.56 -- 8.36 32.2 12,100

PCSP4 7.6 40,800 18.4 4.32 -- 4.64 39 14,800

PCSP5 7.5 37,400 14.5 6.43 -- 9.03 34.8 12,100
8 Characterization of Hydrology and Water Quality of Piceance Creek in the Alkali Flats Area, Colorado

Table 2. Water-quality data and loads at surface-water and spring-sampling sites in the Alkali Flat area, Rio Blanco County, Colorado, 

March 2012.—Continued

[ID, identifier; --, no data; DD, decimal degrees; ft3/sec, cubic feet per second; mg/L, milligram per liter; μS/cm, microsiemens per centimeter; mg/L as CaCO3, 

milligrams per liter as calcium carbonate; μg/L, micrograms per liter; <, less than]

Field site ID

(see fig. 3

for location)

Sodium load 

(pounds/day)

Alkalinity 

(mg/L as 

CaCO3)

Bicarbonate 

(mg/L)

Bicarbonate 

load

(pounds/day)

Chloride, 

dissolved

(mg/L)

Chloride

load 

(pounds/day)

Fluoride,

dissolved

(mg/L)

PC20133 32,059 322 393 118,861 15.2 4,597 0.467

PC20408 32,292 333 406 122,530 15.4 4,648 0.49

PC20708 34,158 340 414 126,263 15.9 4,849 0.5

PC21128 37,743 346 403 131,125 16.9 5,499 0.53

PC21297 37,511 356 434 139,142 17.3 5,546 0.53

PC21299 36,528 355 433 130,716 17.7 5,343 0.53

PC21543 38,822 358 436 136,502 18.7 5,855 0.54

PC21816 41,013 366 446 141,798 19.9 6,327 0.55

PC22031 40,771 376 458 143,638 20.8 6,523 0.55

PC22184 40,978 398 486 153,194 20.5 6,462 0.55

PC22436 42,764 375 457 146,940 20.7 6,656 0.56

PC22737 43,349 379 462 147,259 21.1 6,725 0.57

PC22980 38,803 394 481 132,369 21.8 5,999 0.58

PC23163 37,622 407 497 131,677 22.3 5,908 0.59

PC23357 39,849 401 489 139,188 21.9 6,234 0.59

PC23721 40,835 402 491 140208 22.3 6,368 0.61

PCSP1 -- 7,480 9,120 -- 961 -- 11.8

PCSP2 -- 24,900 30,400 -- 2,420 -- 38

PCSP3 -- 26,800 32,700 -- 2,610 -- 41.3

PCSP4 -- 30,400 37,000 -- 2,930 -- 54.2

PCSP5 -- 27,900 34,000 -- 2,600 -- 54.9

Field site ID

(see fig. 3

for location)

Silica,

dissolved

(mg/L)

Sulfate,

dissolved

(mg/L)

Sulfate

load

(pounds/day)

Dissolved

solids

(mg/L)

Dissolvedsolids load

(pounds/day)

Aluminum,

dissolved

(μg/L)

Aluminum

load

(pounds/day)

PC20133 12.7 233 70,470 673 203,546 17.9 5.41

PC20408 12.9 237 71,526 686 207,034 15.9 4.80

PC20708 12.9 232 70,756 691 210,743 18.6 5.67

PC21128 13.1 232 75,487 698 227,111 16.3 5.30

PC21297 13 230 73,739 703 225,384 12.5 4.01

PC21299 12.9 230 69,433 708 213,734 19.4 5.86

PC21543 13 234 73,260 718 224,790 17.8 5.57

PC21816 12.9 236 75,032 733 233,044 37.2 11.83

PC22031 12.7 234 73,387 736 230,825 21.3 6.68

PC22184 12.6 226 71,238 739 232,943 24.6 7.75

PC22436 12.6 226 72,666 727 233,753 20.4 6.56

PC22737 12.6 231 73,629 742 236,506 20.7 6.60

PC22980 12.7 235 64,671 763 209,975 18.6 5.12

PC23163 12.8 233 61,732 768 203,477 16.6 4.40

PC23357 12.8 236 67,175 767 218,318 19 5.41

PC23721 12.9 231 65,964 763 217,879 17.7 5.05

PCSP1 25.5 27.8 -- 9,010 -- 28.3 --

PCSP2 17.8 <9.00 -- <28,800 -- 124 --

PCSP3 16.8 13.9 -- 30,900 -- 80.3 --

PCSP4 15.2 <9.00 -- <36,100 -- 171 --

PCSP5 19.2 17.4 -- 31,500 -- 73.5 --
Methods of Data Collection 9

Table 2. Water-quality data and loads at surface-water and spring-sampling sites in the Alkali Flat area, Rio Blanco County, Colorado, 

March 2012.—Continued

[ID, identifier; --, no data; DD, decimal degrees; ft3/sec, cubic feet per second; mg/L, milligram per liter; μS/cm, microsiemens per centimeter; mg/L as CaCO3, 

milligrams per liter as calcium carbonate; μg/L, micrograms per liter; <, less than]

Field site ID

(see fig. 3

for location)

Barium,

dissolved

(μg/L)

Barium

load

(pounds/day)

Beryllium,

dissolved

(μg/L)

Cadmium,

dissolved

(μg/L)

Chromium,

dissolved

(μg/L)

Cobalt,

dissolved

(μg/L)

Copper,

dissolved

(μg/L)

Iron,

dissolved

(μg/L)

PC20133 73.3 22.17 <0.006 0.024 0.19 1.6 <0.80 45.2

PC20408 75.4 22.76 <0.006 0.02 0.19 1.78 <0.80 41.2

PC20708 75.8 23.12 <0.006 0.024 0.21 0.475 <0.80 39.9

PC21128 80.6 26.23 <0.006 0.03 0.18 0.841 <0.80 39.7

PC21297 79.7 25.55 <0.006 0.023 0.19 0.775 <0.80 36.5

PC21299 81.2 24.51 <0.006 0.027 0.2 1.01 <0.80 45.3

PC21543 81.6 25.55 <0.006 0.026 0.26 0.991 <0.80 40

PC21816 83.4 26.52 <0.006 0.03 0.23 1.51 <0.80 71.5

PC22031 80.1 25.12 0.007 0.026 0.17 1.01 0.81 41.8

PC22184 80.7 25.44 <0.006 0.031 0.18 0.869 <0.80 53.9

PC22436 82.1 26.40 <0.006 0.027 0.16 0.921 <0.80 46.5

PC22737 80.2 25.56 <0.006 0.028 0.15 0.901 <0.80 44.3

PC22980 81.9 22.54 <0.006 0.026 0.17 1.44 <0.80 46.5

PC23163 83.2 22.04 0.007 0.027 0.18 0.973 <0.80 40.2

PC23357 84.2 23.97 <0.006 0.028 0.18 0.969 <0.80 43.3

PC23721 84.7 24.19 <0.006 0.023 0.17 0.961 <0.80 39.8

PCSP1 5,210 -- 0.185 0.458 <0.56 0.247 <6.4 <32.0

PCSP2 3,790 -- 0.708 0.968 <1.4 <0.420 <16.0 <64.0

PCSP3 3,630 -- 1.09 0.668 <1.4 <0.420 <16.0 <64.0

PCSP4 4,410 -- 1.22 0.925 <3.5 <1.05 <40.0 138

PCSP5 3,560 -- 1.03 0.714 <1.4 <0.420 <16.0 <64.0

Field site ID

(see fig. 3

for location)

Iron

load

(pounds/day)

Lead,

dissolved

(μg/L)

Lithium,

dissolved

(μg/L)

Lithium

load

(pounds/day)

Manganese,

 dissolved

(μg/L)

Molybdenum, 

dissolved

(μg/L)

Nickel, 

dissolved

(μg/L)

PC20133 13.67 0.081 9.38 2.84 16.4 5.52 1.1

PC20408 12.43 0.078 8.72 2.63 18.4 5.69 1.0

PC20708 12.17 0.076 9.91 3.02 19.0 5.65 1.0

PC21128 12.92 0.075 10.4 3.38 20.4 5.89 1.1

PC21297 11.70 0.067 10.3 3.30 20.2 5.90 1.1

PC21299 13.68 0.08 10.2 3.08 19.9 5.67 1.1

PC21543 12.52 0.081 10.7 3.35 20.2 5.74 1.1

PC21816 22.73 0.104 10.8 3.43 20.7 5.71 1.1

PC22031 13.11 0.086 15.4 4.83 18.2 5.69 1.2

PC22184 16.99 0.092 12.6 3.97 16.4 5.55 1.1

PC22436 14.95 0.085 11.1 3.57 15.4 5.46 1.1

PC22737 14.12 0.084 15.2 4.84 17.2 5.60 1.2

PC22980 12.80 0.099 15 4.13 18.7 5.67 1.2

PC23163 10.65 0.075 15.2 4.03 20.3 5.65 1.2

PC23357 12.32 0.076 15.5 4.41 19.3 5.81 1.2

PC23721 11.37 0.074 15.5 4.43 20.5 5.71 1.2

PCSP1 -- <0.200 717 -- 3.1 <0.112 <0.72

PCSP2 -- <0.500 2,110 -- 16.3 0.306 <1.8

PCSP3 -- <0.500 1,920 -- 9.48 <0.280 <1.8

PCSP4 -- <1.25 2,130 -- 14 <0.700 <4.5

PCSP5 -- <0.500 1,960 -- 12.6 <0.280 <1.8
10 Characterization of Hydrology and Water Quality of Piceance Creek in the Alkali Flats Area, Colorado

Table 2. Water-quality data and loads at surface-water and spring-sampling sites in the Alkali Flat area, Rio Blanco County, Colorado, 

March 2012.—Continued

[ID, identifier; --, no data; DD, decimal degrees; ft3/sec, cubic feet per second; mg/L, milligram per liter; μS/cm, microsiemens per centimeter; mg/L as CaCO3, 

milligrams per liter as calcium carbonate; μg/L, micrograms per liter; <, less than]

Field site ID

(see fig. 3

for location)

Silver, 

dissolved

(μg/L)

Strontium, 

dissolved 

(μg/L)

Strontium

load

(pounds/day)

Vanadium, 

dissolved 

(μg/L)

Zinc, 

dissolved

(μg/L)

Antimony, 

dissolved 

(μg/L)

Arsenic, 

dissolved 

(μg/L)

PC20133 <0.005 1,820 550 5.96 <1.4 0.233 2.1

PC20408 <0.005 1,950 589 5.8 <1.4 0.248 2.0

PC20708 <0.005 1,880 573 6.1 <1.4 0.185 2.0

PC21128 <0.005 1,890 615 6.3 <1.4 0.223 2.0

PC21297 <0.005 1,880 603 6.4 <1.4 0.216 2.0

PC21299 <0.005 1,920 580 6.2 <1.4 0.226 2.0

PC21543 <0.005 1,920 601 6.1 <1.4 0.225 2.0

PC21816 <0.005 1,990 633 6.2 <1.4 0.228 2.0

PC22031 0.007 1,750 549 7.1 <1.4 0.214 2.0

PC22184 <0.005 1,820 574 6 <1.4 0.209 2.1

PC22436 <0.005 1,860 598 5.9 <1.4 0.215 2.1

PC22737 0.006 1,780 567 6.6 <1.4 0.18 2.1

PC22980 0.007 1,810 498 6.7 1.7 0.208 2.2

PC23163 0.006 1,820 482 7.1 <1.4 0.21 2.1

PC23357 0.007 1,830 521 6.9 <1.4 0.219 2.2

PC23721 0.007 1,830 523 7.1 <1.4 0.223 2.1

PCSP1 0.991 4,730 -- 2.4 78.5 0.256 <0.24

PCSP2 1.54 1,050 -- 10.1 77.6 <0.540 <0.60

PCSP3 1.45 956 -- 8.2 70.8 <0.540 <0.60

PCSP4 2.06 840 -- 6 226 <1.35 <1.5

PCSP5 1.47 1,010 -- 8.2 58 <.540 <0.60

Field site ID

(see fig. 3

for location)

Boron, 

dissolved

(μg/L)

Boron

load

(pounds/day)

Selenium, 

dissolved

(μg/L)

Uranium

(natural), 

dissolved

(μg/L)

delta

oxygen-18 

(per mil)

Deuterium/

protium ratio 

(per mil)

PC20133 99.9 30 1.03 2.61 -- --

PC20408 92.0 28 1.10 2.7 -- --

PC20708 106 32 1.20 2.7 -- --

PC21128 105 34 1.20 2.76 -- --

PC21297 105 34 1.20 2.72 -- --

PC21299 101 30 1.20 2.69 -- --

PC21543 102 32 1.10 2.71 -- --

PC21816 98.0 31 1.10 2.69 -- --

PC22031 122 38 1.00 2.61 -- --

PC22184 106 33 1.10 2.6 -- --

PC22436 93.0 30 1.10 2.6 -- --

PC22737 121 39 1.00 2.61 -- --

PC22980 120 33 0.990 2.66 -- --

PC23163 124 33 1.00 2.66 -- --

PC23357 125 36 1.10 2.68 -- --

PC23721 124 35 1.00 2.67 -- --

PCSP1 1,150 -- <0.24 <0.032 –18.04 –143

PCSP2 5,540 -- <0.60 <0.080 –17.51 –141

PCSP3 5,730 -- <0.60 <0.080 –17.49 –142

PCSP4 6,430 -- <1.5 <0.200 –17.6 –144

PCSP5 5,370 -- <0.60 <0.080 –17.4 –143
Characterization of Surface-Water Hydrology 11

analysis of trace elements and major ions at all 16 stream sites. 

Temperature, specific conductance, pH, and dissolved oxygen 

were measured in-situ using a multiparameter sonde in the 

stream. Sondes were calibrated according to standard procedures outlined in the National Field Manual (U.S. Geological 

Survey, 2012). Sample processing involved filtering the 

sample (0.45-micrometer capsule filter) in the field and storing the sample in precleaned plastic bottles. Alkalinity was 

determined by incremental titration from an aliquot of filtered 

sample in the processing vehicle. Filtered samples for analysis 

of trace elements and major cations were acidified in the field 

to pH less than 2 using nitric acid. Additional filtered, unacidified samples were collected for analysis of major anions. 

Samples for trace elements and major ions were submitted 

to the USGS National Water Quality Laboratory (NWQL) 

for analysis. Trace elements analyzed included aluminum, 

antimony, arsenic, barium, beryllium, boron, cadmium, 

chromium, cobalt, copper, iron, lead, lithium, manganese, 

molybdenum, nickel, selenium, silver, strontium, uranium 

(natural), vanadium, and zinc (Garbarino, 1999). When values 

are estimated by the NWQL, an “E” remark code proceeds 

the numeric value (Childress and others, 1999). Major ions 

included bromide (only analyzed in the December 2010 

samples), calcium, chloride, fluoride, magnesium, potassium, silica, sodium, and sulfate (Fishman and Friedman, 

1989). All data collected as part of this study are available 

via the National Water Information System (NWISWeb at 

http://nwis.waterdata.usgs.gov/co/nwis/). Data were compared 

to previous studies (Ortiz, 2002), groundwater-quality data 

(Thomas and McMahon, 2013), and field-reconnaissance data.

During late March 2012, the five springs were sampled. 

Spring samples were collected by inserting a drive point into 

the spring (figs. 4A and B). The drive point was made using 

electrical conduit (galvanized metal) approximately 5 feet 

long and 0.5 inch in diameter. The end of this conduit was 

hammered closed and holes were drilled to allow water to 

enter the drive point near the closed end (fig. 4A). Samples 

were pumped from the drive point using a peristaltic pump 

(fig. 4B). Field properties, trace elements, and major ions were 

collected at all five spring sites, as described previously for 

surface-water sites. In addition, unfiltered, unacidified samples 

were collected for stable isotopes of water (delta oxygen-18 

(δ18O[H2O]), and deuterium/protium,(δ2H[H2O])) for all five 

spring sites. The unfiltered sample was collected in a 2-ounce 

glass bottle with polyseal cap provided by USGS Reston 

Stable Isotope Laboratory (RSIL). Samples were stored at 

ambient temperature and shipped to RSIL for analysis. Stable 

isotopes were analyzed by hydrogen and carbon dioxide 

gas equilibration and mass spectrometry (U.S. Geological 

Survey, 2013).

Approximately 10 percent of the samples collected 

were quality-control samples, which included equipment 

blanks, replicates, and field blanks. The equipment blank 

of the spring-sampling apparatus resulted in detections of 

calcium, sodium, barium, cobalt at low concentrations close 

to the reporting level; however, iron and zinc were found 

at higher concentrations in the equipment blank (28 micrograms per liter and 7.6 micrograms per liter respectively). The 

spring-sampling apparatus is constructed from galvanized 

electrical conduit; it is likely that this material is the source of 

these detections in the equipment blank. These detections do 

not affect the analysis as they are at concentrations well below 

those detected in the springs. No detections were found in 

field blank samples. All major-ion concentrations in replicate 

pairs were within 5 percent of each other based on the relative 

percent difference (RPD), which is the difference between the 

replicate values divided by the mean of the replicate values 

times 100. The majority of trace-element concentrations in 

replicate pairs were within 10 percent (RPD) of each other 

with the exception of boron (14 percent), chromium (54 percent), vanadium (12 percent), aluminum (12 percent), lithium 

(19 percent), and selenium (12 percent). Charge balances 

derived from summation of major cations and anions were 

less than 10 percent.

Loading profiles were used to aid in understanding the 

hydrology along Piceance Creek. The profiles were constructed with instantaneous loads that were calculated by 

multiplying concentration (milligrams per liter or micrograms 

per liter) times streamflow (cubic feet per second) and a unit 

conversion factor.

Characterization of Surface-Water 

Hydrology

In a previous USGS investigation of Piceance Creek 

(Ortiz, 2002), a decrease in streamflow (approximately 

5 cubic feet per second [ft3/s]) was observed between 

12.9 miles and 14.7 miles downstream from Piceance Creek 

at Ryan Gulch station number 09306200). Instantaneous 

streamflow was measured from sites PC20133 to PC23721 

during field reconnaissance (February 2012) and during 

synoptic sampling (March 2012). Distances between sites 

ranged from around 7 to 1,400 feet, with a median distance of 

around 800 feet. Continuous streamflow at Piceance Creek at 

Ryan Gulch and Piceance Creek at White River were used to 

understand overall flow conditions during both February 2012 

reconnaissance and March 2012 synoptic sampling (figs. 5 and 

6). Conditions were represented in the study reach by shifting continuous streamflow in Piceance Creek at Ryan Gulch 

7 hours forward in time based on an average stream velocity 

of 2.5 feet per second (ft/s) and a distance of 66,000 feet from 

sites PC0 to PC20133. Continuous streamflow in Piceance 

Creek at White River was shifted 1.7 hours backward in time 

based on an average stream velocity of 2.5 ft/s and a distance 

of 15,000 feet from sites PC23721 to PC28348. Site reconnaissance during February 2012 was conducted during 3 days 

(February 22, 23, and 29, 2012) (fig. 5) and streamflow at the 
12 Characterization of Hydrology and Water Quality of Piceance Creek in the Alkali Flats Area, Colorado

Figure 4. Photograph of drive point end showing perforation and hammered end. B, Photograph of deployed drive 

point in spring (site PCSP3) with tubing and peristaltic pump.

A

B
Characterization of Surface-Water Hydrology 13

Figure 5. Instantaneous streamflow measurements and continuous streamflow from U.S. Geological Survey gaging station within 

the study reach, Piceance Creek in the Alkali Flat area, Rio Blanco County, Colorado, February 22–29, 2012.

15

20

25

30

35

40

45

50

02/22/2012

02/23/2012

02/24/2012

02/25/2012

02/26/2012

02/27/2012

02/28/2012

02/29/2012

Date

EXPLANATION

Instantaneous streamflow measurements 

 collected within study reach

Error bar (5 percent)

Station 09306200, shifted 7 hours forward 

 in time to study reach

Station 09306222, shifted 1.7 hours back 

 in time to study reach

Streamflow, in cubic feet per second

35

40

45

50

55

60

65

Instantaneous streamflow measurements

 collected within study reach

Station 09306200, shifted 7 hours forward

 in time to study reach

Station 09306222, shifted 1.7 hours back in

 time to study reach

Error bar (5 percent)

EXPLANATION

Time, 24-hour

Streamflow, in cubic feet per second

0448 0600 0712 0824 0936 1048 1200 1312 1424 1536 1648 1804 1912 2024

Figure 6. Instantaneous streamflow measurements and continuous streamflow from U.S. Geological Survey gaging stations within 

the study reach, Piceance Creek in the Alkali Flat area, Rio Blanco County, Colorado, March 14, 2012.
14 Characterization of Hydrology and Water Quality of Piceance Creek in the Alkali Flats Area, Colorado

gages was relatively stable during this period. Synoptic sampling was conducted in a single day (March 14, 2012) when 

streamflow at the gages was relatively stable (fig. 6).

Instantaneous streamflow measurements collected during February and March allow for examination of streamflow gains and losses along the study reach (fig. 7). During 

February and March, changes in streamflow were observed 

along the study reach (fig. 7). During February, streamflow 

increased 6 ft3/s from 27 ft3/s at site PC20133 to 33 ft3/s at 

site PC21816 (downstream distances of 12.5 and 13.6 miles, 

respectively). Just downstream, streamflow decreased 5.5 ft3/s 

from 33 ft3/s at site PC21816 to 27.5 ft3/s at site PC23721 

(downstream distance 14.7 miles). During February, the 

study reach from sites PC20133 to PC23721 was a losing 

reach with net losses of 0.5 ft3/s. During March, streamflow 

increased 4 ft3/s from 56 ft3/s at site PC20133 to 60 ft3/s at 

site PC21128 (downstream distance 13.1 miles). Downstream, 

streamflow decreased 7 ft3/sec from 60 ft3/s at site PC21128 to 

53 ft3/s at site PC23721. During March, the study reach from 

sites PC20133 to PC23721 was a losing reach with net losses 

of 3 ft3/s. Observed changes in streamflow along the study 

reach helped to depict interactions between groundwater and 

surface water in the Alkali Flat area.

Characterization of SurfaceWater Quality

Water-quality samples were collected at five sites in 

December 2010 that were sampled as part of a previous 

USGS study (Ortiz, 2002) to understand and identify potential changes that may have occurred since 2000 (table 1 and 

fig. 1). Sites were located upstream (PC5280, PC14789, and 

PC16210), within (PC20708), and downstream (PC24787) 

from the Alkali Flat area (table 1 and fig. 1). Water-quality 

data collected during December 2010 showed no appreciable difference from water-quality data collected during 

December 2000 at the five sites (table 1).

Water-quality samples were collected at 16 surface-waterquality sites on March 14, 2012, to determine field properties, 

and major-ion and trace-element concentrations (table 2). 

Sampling was conducted to collect samples as close in time to 

one another to minimize streamflow variability between sites 

and to provide a snapshot of water-quality conditions within 

the study reach. Field properties of dissolved oxygen, pH, 

specific conductance, and temperature were measured in the 

stream at sites during sampling. Values of dissolved oxygen, 

Figure 7. Instantaneous streamflow measurements along the study reach, Piceance Creek in the Alkali 

Flat area, Rio Blanco County, Colorado, February and March 2012.

12.4 13.0 13.7 14.3 14.9 15.5 16.2 16.8 17.4 18.0

Measured streamflow

Daily median streamflow 

 at station 09306222

Reconnaissance event 

 (February 2012)

Measured streamflow

Sampling event (March 2012)

Daily median streamflow

 at station 09306222

Approximate location of springs 

 along study reach (with site 

 identifier PCSP1 through PCSP5) 

Error bar (8 percent)

Distance downstream from U.S. Geological Survey 

streamflow-gaging station 09306200,

in miles

Streamflow,

in cubic feet per second

EXPLANATION
Characterization of Surface-Water Quality 15

pH, and temperature remained relatively stable along the 

study reach with median values of 10.05 milligrams per liter 

(mg/L) for dissolved oxygen, 8.5 standard units for pH, and 

5.7 degrees Celsius for temperature (table 2). Specific conductance increased along the study reach with values that ranged 

from 1,030 microsiemens per centimeter at 25 degrees Celsius 

(μS/cm) to 1,140 μS/cm with a median of 1,080 μS/cm.

Sodium was the dominant cation in the study reach in 

2012 with concentrations that ranged from 106 to 143 mg/L 

with a median concentration of 129 mg/L (table 2). Concentrations increased steadily along the study reach with a total 

increase of 35 percent from upstream to downstream (fig. 8). 

Calcium, magnesium, and potassium concentrations remained 

relatively stable along the study reach with median concentrations of 58.7 mg/L, 48.3 mg/L, and 3.8 mg/L, respectively 

(table 2 and fig. 8). Bicarbonate and chloride concentrations 

were observed to increase along the study reach. Titration 

indicates bicarbonate was the dominant ion in alkalinity with 

carbonate being less than 5 mg/L. Bicarbonate concentrations increased by 25 percent from upstream to downstream 

(fig. 9). Bicarbonate concentrations ranged from 393 mg/L to 

497 mg/L with a median concentration of 451 mg/L (table 2). 

Chloride concentrations ranged from 15.2 to 22.3 mg/L, an 

increase of 47 percent from upstream to downstream and the 

median concentration was 20.2 mg/L (table 2). Dissolved 

solids concentrations ranged from 673 to 768 mg/L, an 

increase of 14 percent from upstream to downstream and 

the median concentration was 730 mg/L (table 2). Sodium, 

bicarbonate, and chloride concentrations increased appreciably 

from PC20708 to PC22031 (12.9 and 13.7 miles downstream, 

respectively) indicating an area of input of springs and (or) 

groundwater to Piceance Creek (fig. 9). Sulfate, silica, and 

fluoride concentrations remain relatively stable along the study 

reach with median concentrations of 232 mg/L, 12.8 mg/L, 

and 0.55 mg/L, respectively (table 2 and fig. 9).

Strontium concentrations along the study reach ranged 

from 1,750 micrograms per liter (μg/L) to 1,990 μg/L with a 

median strontium concentration of 1,850 μg/L (table 2). Strontium concentrations remained relatively stable along the study 

reach, similar to what was observed in previous studies (Ortiz, 

2002) (table 2 and fig. 10). Barium concentrations increased 

slightly along the study reach, ranging from 73.3 to 84.7 with 

a median concentration of 81 μg/L. Boron and lithium concentrations increased appreciably at site PC22031 (13.7 miles 

downstream) and remained elevated to the end of the study 

reach (fig. 10), which indicated an area of focused input 

from springs and (or) groundwater to Piceance Creek. Boron 

concentrations ranged from 92 to 125 μg/L with a median 

of 105 μg/L (table 2). Lithium concentrations ranged from 

8.72 to 15.5 μg/L, an increase of 78 percent from upstream 

to downstream, and the median concentration was 10.9 μg/L 

(table 2).

Aluminum and iron concentrations were greater than 

those observed in the Ortiz study (2002). Aluminum concentrations ranged from 12.5 to 37.2 μg/L with a median 

concentration of 18.6 μg/L (table 2) compared to previous 

studies where aluminum concentrations ranged from less than 

detection (less than 0.1 μg/L) to 2.7 μg/L (Ortiz, 2002). Iron 

0

20

40

60

80

100

120

140

160

Sodium, filtered, milligrams per liter

Calcium, filtered, milligrams per liter

Magnesium, filtered, milligrams per liter

Concentration, in milligrams per liter

12.4 12.7 13.0 13.4 13.4 14.0 14.3 14.6 14.9

Distance downstream from U.S. Geological Survey 

streamflow-gaging station 09306200, 

in miles

PCSP1PCSP2

PCSP3, 4, and 5

EXPLANATION

Approximate location of springs along 

 study reach (with site identifier PCSP1 

 through PCSP5) 

Figure 8. Selected dissolved-cation concentrations March 14, 2012, Piceance Creek in the Alkali Flat area, Rio Blanco County, Colorado.
16 Characterization of Hydrology and Water Quality of Piceance Creek in the Alkali Flats Area, Colorado

Figure 9. Selected dissolved-anion concentrations March 14, 2012, Piceance Creek in the Alkali Flat area, Rio Blanco County, Colorado.

0

100

200

300

400

500

600

Bicarbonate, milligrams per liter

Alkalinity, milligrams per liter as 

 calcium carbonate

Sulfate, filtered, milligrams per liter

0

5

10

15

20

25

Distance downstream from U.S. Geological Survey 

streamflow-gaging station 09306200, 

in miles

Chloride, filtered, milligrams per liter

Silica, filtered, milligrams per liter as S

Fluoride, filtered, milligrams per liter

12.4 12.7 13.0 13.4 13.7 14.0 14.3 14.6 14.9

Distance downstream from U.S. Geological Survey 

streamflow-gaging station 09306200, 

in miles

12.4 12.7 13.0 13.4 13.7 14.0 14.3 14.6 14.9

Concentration, in milligrams per liter Concentration, in milligrams per liter

Approximate location of springs along 

 study reach (with site identifier PCSP1 

 through PCSP5) 

Approximate location of springs along 

 study reach (with site identifier PCSP1 

 through PCSP5) 

PCSP1PCSP2PCSP3, 4, and 5

PCSP1PCSP2PCSP3, 4, and 5

EXPLANATION

EXPLANATION
Sources of Recharge to Springs and Spring Contribution to Piceance Creek 17

concentrations ranged from 36.5 to 71.5 μg/L with a median 

concentration of 42.5 μg/L (table 2) compared to previous 

studies where iron concentration were less than detection (less 

than 10 μg/L to less than 30 μg/L) (Ortiz, 2002). The reason 

for the observed increase in concentration of both aluminum 

and iron between previous studies and concentrations observed 

on March 14, 2012, was unclear and inconsistent with other 

trace-element concentrations between the two study periods.

Sources of Recharge to Springs and 

Spring Contribution to Piceance Creek

Water-quality samples were collected at five springs on 

March 27, 2012, to determine field properties, major ions, 

trace elements, and stable isotopes of water (table 2, fig. 3). 

Field properties of dissolved oxygen, pH, specific conductance, and temperature were measured in the springs during 

sampling (table 2). Dissolved-oxygen concentrations at all 

springs were less than 0.5 mg/L indicating suboxic or anoxic 

conditions, and values of pH ranged from 7.5 to 7.8. Specific conductance ranged from 12,700 μS/cm at site PCSP1 

to 40,800 μS/cm at site PCSP4, and temperatures ranged 

from 14.5 degrees Celsius at sites PCSP1 and PCSP5 to 

18.4 degrees Celsius at site PCSP4 (table 2). Site PCSP4 

generally had the highest concentrations of sodium, chloride, and bicarbonate, whereas site PCSP1 had the lowest. 

Site PCSP4 had the highest concentrations of aluminum 

and iron, 171 μg/L and 138 μg/L, respectively, whereas site 

PCSP1 had the lowest concentrations of aluminum and iron, 

28.3 μg/L and less than 32.0 μg/L, respectively. Sites PCSP2, 

PCSP3, PCSP4, and PCSP5 were similar to one another in 

major-ion and trace-element chemistry; however, site PCSP4 

had the highest concentrations of sodium, chloride, bicarbonate, lithium, and boron, and the lowest concentrations 

of calcium, magnesium, and strontium of the four springs. 

Piceance Creek water was a mixed-cation-bicarbonate-sulfate 

type water, whereas spring water was a sodium-bicarbonate 

type water (fig. 11). Trace-element concentrations in the 

stream samples were substantially lower than those in spring 

samples (table 2). Major-ion and trace-element chemistry indicate that the springs sampled as part of this study were likely 

recharged by the bedrock aquifer (McMahon and others, 2013; 

Tobin, 1987).

Approximate location of springs along 

 study reach (with site identifier PCSP1 

 through PCSP5) 

12.4 12.7 13.0 13.4 13.7 14.0 14.3 14.6 14.9

1,000

1,500

2,000

2,500

3,000

3,500

PCSP1PCSP2PCSP3, 4, and 5

0

20

40

60

80

100

120

140

Strontium, in micrograms per liter

Concentrations, in micrograms per liter

Distance downstream from U.S. Geological Survey 

streamflow-gaging station 09306200,

in miles

Barium, filtered, micrograms per liter

Boron, filtered, micrograms per liter

Lithium, filtered, micrograms per liter

Strontium, filtered, micrograms per liter

EXPLANATION

Figure 10. Selected dissolved trace-element concentrations March 14, 2012, Piceance Creek in the 

Alkali Flat area, Rio Blanco County, Colorado.
18 Characterization of Hydrology and Water Quality of Piceance Creek in the Alkali Flats Area, Colorado

Figure 11. Major-ion chemistry of water from Piceance Creek and spring samples, 

Piceance Creek in the Alkali Flat area, Rio Blanco County, Colorado.

The stable isotopic composition of spring water helps 

determine sources of recharge to the springs. Isotopic values 

for the springs are similar to those of groundwater from the 

Parachute Creek Member of the Green River Formation, and 

the isotopic values from both of these sources are similar to 

the values for Grand Mesa snow (McMahon and others, 2013) 

(fig. 12). Recharge to the Parachute Creek Member of the 

Green River Formation was mostly derived from snowmelt 

infiltrating into the bedrock aquifers at higher elevations, 

which then was the likely source of water to the springs in the 

Alkali Flat area. Because spring samples did not have isotopic compositions that were at all similar to that of produced 

water from the Mesaverde Group, this source can be ruled out 

(fig. 12). The positive shift of the isotopic values for groundwater compared to snow indicates water may have undergone 

some evaporation prior to recharging the aquifers. Spring 

samples were shifted even further in the positive direction than 

groundwater samples, which may indicate that spring water 

has undergone additional evaporation after discharging to the 

land surface (fig. 12).

Springs and groundwater contribute to surface-waterquality changes in Piceance Creek along the study reach. 

Loading profiles were used to further refine areas of spring and 

groundwater input and streamflow gains and losses. Although 

there was a minor gain in streamflow from sites PC21543 to 

PC21816 (58 to 59 ft3/s during March 2014 at downstream distances of 13.4 and 13.6 miles), the increase in dissolved solids 

load indicated groundwater contribution to Piceance Creek 

between these two sites. From sites PC22737 to PC22980 

(downstream distances 14.1 and 14.3 miles), dissolved solids 

load decreases (fig. 13), which was not observed in concentration data (table 2) and provides additional insight to streamflow loss identified earlier in the report to occur between these 

two sites. Sodium, calcium, bicarbonate, sulfate, and chloride 

loads increase and decrease along the study reach in a similar 

pattern to that of dissolved solids load (fig. 13).

Concentrations of most trace elements (barium, lithium, 

zinc, and boron) in springs were greater than those of surface 

water, whereas strontium concentrations were similar between 

four of the springs and surface water (table 2). Previous studies have identified the two major bedrock aquifers in Piceance 

Creek as having characteristic trace elements where strontium is found in high concentrations in association with the 

Uinta Formation and barium, boron, and lithium are found in 

high concentrations in association with the lower portion of 

the Parachute Creek Member of the Green River Formation 

PERCENT Calcium

100

80

60

40

20

0

0

20

40

60

80

100

Magnesium

0

20

40

60

80

100

Sodium + potassium

Chloride + fluoride

0

20

40

60

80

100

100

80

60

40

20

0

Bicarbonate

100

80

60

40

20

 0

Sulfate

0

20

40

60

80

100

Sulfate + chloride

0

20

40

60

80

100

Calcium + magnesium

100

80

60

40

20

0

100

80

60

40

20

0

EXPLANATION

Spring sites

Stream sites

PERCENT

PERCENT
Sources of Recharge to Springs and Spring Contribution to Piceance Creek 19

(Tobin, 1987). Based on fluoride, lithium, and strontium 

concentrations, site PCSP1 appeared to have different source 

water than the other four springs. Site PCSP1 also had higher 

concentrations of calcium, magnesium, and sulfate relative 

to the other four springs. Trace-element and major-ion data 

indicate site PCSP1 was sourced from the Uinta Formation. It 

was likely the other four springs were primarily sourced from 

the lower portion of the Parachute Creek Member of the Green 

River Formation as indicated by low sulfate concentrations 

and high fluoride, lithium, and boron concentrations.

Barium, boron, lithium, and strontium loads showed 

similar patterns to that of the major ions along the study reach 

indicating similar areas of groundwater gain and loss. Boron 

and lithium loads increased between sites PC22031 and 

PC22737 (downstream distances 13.1 and 13.7, respectively), 

a pattern not observed in barium and strontium loads (fig. 14). 

Barium and strontium loads were generally stable along the 

study reach until site PC21816 (downstream distance 13.6) 

after which the loads generally decreased to the end of the study 

reach indicating streamflow loss (fig. 14). Boron and lithium 

were not observed to decrease in a similar pattern to that of 

barium and strontium which would suggest the contribution to 

the stream from sources with similar chemistry to that of spring 

sites PCSP2 through PCSP5. Sites PCSP2 through PCSP5 had 

concentrations of lithium and boron greater than 1,900 μg/L 

and 5,000 μg/L, respectively. Because lithium and boron loads 

in Piceance Creek do not increase along the study reach, they 

also indicate a loss of streamflow and agree with the findings 

observed with the other constituents.

Although it was clear from this study that groundwater 

and (or) spring water was contributing to changes in water 

quality in Piceance Creek, the amount of groundwater and 

(or) spring water that resulted in these changes was unknown. 

In order to estimate the amount of groundwater and (or) spring 

water that was contributing to changes in water quality along 

Piceance Creek, a chemical mass balance approach was used. 

Chloride is a conservative constituent and was used to estimate 

the amount of groundwater and (or) spring water that was being 

added to Piceance Creek. The amount of groundwater and (or) 

spring-water flux was determined for the mostly gaining portion 

of the stream from sites PC20133 to PC22737 by subtracting 

the streamflow at sites PC20133 from PC22737 (table 2). The 

chloride load at site PC20133 was subtracted from the load at 

site PC22737 (table 2) and the result represented the chloride 

load from groundwater/spring-water contributions. The chloride load (expressed as milligrams per second) divided by the 

groundwater and (or) spring-water flux (expressed as liters per 

second) represents the approximate concentration of chloride 

of the groundwater and (or) spring-water input (expressed 

as milligrams per liter). Dividing this concentration by the 

median chloride concentrations of the five springs sampled 

(2,600 mg/L), it would take only 5 percent of the spring water to 

reach Piceance Creek to result in the observed changes in water 

quality in Piceance Creek. It is not understood how variable this 

contribution is, but it would be important to understand if certain activities such as nahcolite mining, gas development, or oil 

shale development could increase this contribution and possibly 

degrade the water quality in Piceance Creek.

–200

–180

–160

–140

–120

–100

–80

–60

–40

–20

0

–25 –20 –15 –10 –5 0

δ2H[H O], in per mil relative to Vienna Standard Mean Ocean Water 2

δ18O[H2O], in per mil relative to Vienna Standard Mean Ocean Water

Global meteoric water line (Craig, 1961)

Mesaverde Group produced waters from Garfield 

 County, Colorado

Snow from Grand Mesa, Colorado

Alkali Flat Springs

Groundwater data from Green River Formation

EXPLANATION

Figure 12. Stable isotopic composition of water (delta oxygen-18, δ18O[H2O], and deuterium/protium -, δ2H[H2O]) from springs in 

the Alkali Flat area compared to groundwater from the Green River Formation, snow from Grand Mesa, Colorado, and produced 

waters from the Mesaverde Group in Piceance Basin, western Colorado.
20 Characterization of Hydrology and Water Quality of Piceance Creek in the Alkali Flats Area, Colorado

Figure 13. Selected dissolve-cation and dissolved-anion loads for March 14, 2012, Piceance Creek in the Alkali Flat area, Rio Blanco 

County, Colorado.

200,000

205,000

210,000

215,000

220,000

225,000

230,000

235,000

240,000

0

5,000

10,000

15,000

20,000

25,000

30,000

35,000

40,000

45,000

50,000

Dissolved solids load, in pounds per day

Constituent load, in pounds per day

Sodium load (pounds/per day)

Calcium load (pounds/ per day)

Dissolved solids load 

 (pounds/day)

0

1,000

2,000

3,000

4,000

5,000

6,000

7,000

8,000

0

20,000

40,000

60,000

80,000

100,000

120,000

140,000

160,000

180,000

Chloride load, in pounds per day

Constituent load, in pounds per day

Distance downstream from U.S. Geological Survey

streamflow-gaging station 09306200,

in miles

Distance downstream from U.S. Geological Survey

streamflow-gaging station 09306200,

in miles

Bicarbonate

Sulfate 

Chloride

12.4 12.7 13.0 13.4 13.7 14.0 14.3 14.6 14.9 PCSP1 PCSP2 PCSP3, 4, and 5 PCSP1 PCSP2 PCSP3, 4, and 5

Approximate location of 

 springs along study reach 

 (with site identifier PCSP1 

 through PCSP5) 

Approximate location of 

 springs along study reach 

 (with site identifier PCSP1 

 through PCSP5) 

EXPLANATION

EXPLANATION

12.4 12.7 13.0 13.4 13.7 14.0 14.3 14.6 14.9
Sources of Recharge to Springs and Spring Contribution to Piceance Creek 21

Figure 14. Selected dissolved trace-element loads for March 14, 2012, Piceance Creek in the Alkali Flat area, Rio Blanco County, 

Colorado.

12.4 12.7 13.0 13.4 13.7 14.0 14.3 14.6 14.9

Distance downstream from U.S. Geological Survey 

streamflow-gaging station 09306200, 

in miles

12.4 12.7 13.0 13.4 13.7 14.0 14.3 14.6 14.9

Distance downstream from U.S. Geological Survey 

streamflow-gaging station 09306200, 

in miles

PCSP1PCSP2PCSP3, 4, and 5

PCSP1PCSP2PCSP3, 4, and 5

0

5

10

15

20

25

30

35

40

45

Constituent load, in pounds per day

Barium 

Boron

0

100

200

300

400

500

600

700

0

2

4

6

8

10

12

14

Strontium load, in pounds per day

Lithium load, in pounds per day

Lithium

Strontium

EXPLANATION

EXPLANATION

Approximate location of 

 springs along study reach 

 (with site identifier PCSP1 

 through PCSP5) 

Approximate location of 

 springs along study reach 

 (with site identifier PCSP1 

 through PCSP5) 
22 Characterization of Hydrology and Water Quality of Piceance Creek in the Alkali Flats Area, Colorado

Summary

Previous studies by the U.S. Geological Survey (USGS) 

identified Alkali Flat as an area of groundwater upwelling, 

with increases in concentrations of total dissolved solids, 

and streamflow loss, but additional study would be needed to 

better characterize these observations. The U.S. Geological 

Survey, in cooperation with the Bureau of Land Management, 

White River Field Office, conducted a study to further characterize surface-water hydrology and surface-water quality 

of Piceance Creek in the Alkali Flat area. The purpose of this 

report was to characterize the hydrology and water quality of 

Piceance Creek in the Alkali Flat area to further understand 

areas of streamflow gain and loss.

Instantaneous streamflow was measured from 

sites PC20133 to PC23721 during field reconnaissance 

(February 2012) and during synoptic sampling (March 2012). 

Continuous streamflow at Piceance Creek at Ryan Gulch and 

Piceance Creek at White River were used to understand overall flow conditions during both February 2012 reconnaissance 

and March 2012 synoptic sampling. Instantaneous streamflow 

measurements collected during February and March allow for 

examination of streamflow gains and losses along the study 

reach. During both February and March, the study reach from 

sites PC20133 to PC23721 was a losing reach with net losses 

ranging from 0.5 cubic foot per second (February) to 3 cubic 

foot per second (March). Observed changes in streamflow 

along the study reach helped to depict interactions between 

groundwater and surface water in the Alkali Flat area.

Water-quality samples were collected at five sites in 

December 2010 that were sampled as part of a previous USGS 

study to understand and identify potential changes that may 

have occurred since 2000. Water-quality data collected during 

December 2010 showed no appreciable difference from waterquality collected during December 2000 at the five sites.

Water-quality samples were collected at 16 surface-water 

quality sites on March 14, 2012, to determine field properties, 

major ions, and trace elements. Sodium was the dominant cation and concentrations increased steadily along the study reach 

with a total increase of 35 percent from upstream to downstream. Calcium, magnesium, and potassium concentrations 

remained relatively stable along the study reach. Bicarbonate 

and chloride concentrations increased, whereas sulfate, silica, 

and fluoride concentrations were relatively stable along the 

study reach. Strontium concentrations were relatively stable 

along the study reach, similar to what was observed in previous studies. Boron and lithium concentrations increased appreciably at site PC22031 and remained elevated to the end of the 

study reach indicating an area of focused input from springs 

and (or) groundwater to Piceance Creek. Aluminum and iron 

concentrations were greater than those observed in previous 

studies. The reason for the observed increase in concentration of both aluminum and iron between previous studies and 

concentrations observed on March 14, 2012, was unclear and 

inconsistent with other trace-element concentrations between 

the two study periods.

Water-quality samples were collected at five springs on 

March 27, 2012, to determine field properties, major ions, 

trace elements, and stable isotopes of water. Major-ion and 

trace-element chemistry indicate that the springs sampled as 

part of this study were likely recharged by the bedrock aquifer. 

Isotopic values for the springs are similar to those of groundwater from the Parachute Creek Member of the Green River 

Formation, and the isotopic values from both of these sources 

are similar to the values for Grand Mesa snow. Springs and 

groundwater contribute to surface-water quality changes in 

Piceance Creek along the study reach. Loading profiles were 

used to further refine areas of spring and groundwater input 

and streamflow gains and loss. Although there was a minor 

gain in streamflow from sites PC21543 to PC21816 (58 to 

59 cubic feet per second during March 2014), the increase in 

dissolved solids load indicated groundwater contribution to 

Piceance Creek between these two sites. From sites PC22737 

to PC22980, dissolved solids load decreases, which was not 

observed in concentration profiles and provides additional 

insight to streamflow loss identified earlier in the report to 

occur between these two sites. Sodium, calcium, bicarbonate, 

sulfate, and chloride loads increase and decrease along the 

study reach in a similar pattern to that of dissolved solids load. 

Trace-element concentrations in springs were typically greater 

than those of surface water, whereas barium, lithium, zinc, 

and boron concentrations in springs were greater than those 

observed in surface water. Strontium concentrations were 

similar between four of the springs and surface water. Previous studies have identified the two major bedrock aquifers in 

Piceance Creek as having characteristic trace elements where 

strontium is found in high concentrations in association with 

the Uinta Formation, and barium, boron, and lithium are found 

in high concentrations in association with the lower portion of 

the Parachute Creek Member of the Green River Formation. 

Based on fluoride, lithium, and strontium concentrations, 

site PCSP1 appeared to have different source water than the 

other four springs. It was likely the other four springs were 

primarily sourced from the lower portion of the Parachute 

Creek Member of the Green River Formation as indicated 

by low sulfate concentrations and high fluoride, lithium, and 

boron concentrations. Barium, boron, lithium, and strontium 

loads showed similar patterns to that of the major ions along 

the study reach and indicated similar areas of groundwater 

gain and loss. Boron and lithium were not observed to 

decrease in a similar pattern to that of barium and strontium 

which would suggest the contribution to the stream from 

sources with similar chemistry to that of spring sites PCSP2 

through PCSP5.

Although it was clear from this study that groundwater 

and (or) spring water was contributing to changes in water 

quality in Piceance Creek, the amount of groundwater and (or) 

spring water that resulted in these changes was unknown. In 

order to estimate the amount of groundwater and (or) spring 

water that was contributing to these changes in water quality along Piceance Creek, a chemical mass balance approach 

was used. Based on this analysis, it would take only 5 percent 
References Cited 23

of the spring water to reach Piceance Creek to result in the 

observed changes in water quality in Piceance Creek. The 

variability of this contribution is not understood within the 

study area, but it would be important to understand if activities such as nahcolite mining, gas development, or oil shale 

development could increase the contribution from the study 

area and possibly degrade the water quality in Piceance Creek 

downstream of Alkali Flat.

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Gary, J.H., ed., Proceedings, 16th Oil Shale Symposium: 

Colorado School of Mines Press, Golden, Colo., p. 26–44.

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Thomas, J.C.—Characterization of Hydrology and Water Quality of Piceance Creek in the Alkali Flat Area, Colorado—Scientific Investigations Report 2015–5147

ISSN 2328-0328 (online)

http://dx.doi.org/10.3133/sir20155147