In cooperation with the U.S. Environmental Protection Agency

Geochemical Data from Groundwater at the Proposed 

Dewey Burdock Uranium In-Situ Recovery Mine, 

Edgemont, South Dakota

By Raymond H. Johnson

Open-File Report 2012–1070

U.S. Department of the Interior

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

KEN SALAZAR, Secretary

U.S. Geological Survey

Marcia K. McNutt, Director 

U.S. Geological Survey, Reston, Virginia: 2012 

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Suggested citation: 

Johnson, R.H., 2012, Geochemical data from groundwater at the proposed Dewey Burdock uranium in-situ recovery 

mine, Edgemont, South Dakota: U.S. Geological Survey, Open-File Report 2012–1070, 11 p. 

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iii

Contents

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

Introduction.................................................................................................................................................................... 1 

Sampling Methods......................................................................................................................................................... 2 

Analytical Methods......................................................................................................................................................... 3 

Data............................................................................................................................................................................... 4 

Quality Assurance/Quality Control................................................................................................................................. 4 

Acknowledgments ......................................................................................................................................................... 5 

References Cited........................................................................................................................................................... 5 

Figures

1. Location of study area............................................................................................................................................. 6 

2. Map showing satellite imagery overlain with monitoring well locations ................................................................... 7 

3. Expanded view of Dewey area................................................................................................................................ 8 

4. Expanded view of Burdock area.............................................................................................................................. 9 

5. Typical wellhead control valves..............................................................................................................................10

6. "T-valve" used for sampling....................................................................................................................................11

Tables

[Click on title to view in Excel or PDF format]

1. Bottle type and size, rinsing, filtration, and preservation for analytes...................................................................... 3 

2. Locations and geochemical data for groundwater samples.................................................................................. link

3. Geochemical data for duplicates and blanks........................................................................................................ link

Appendixes

[Click on title to view in Excel or PDF format]

A. EPA-DOC.xlsx ..................................................................................................................................................... link

B. EPA-anions.xls .................................................................................................................................................... link

C. EPA-O&D.xls....................................................................................................................................................... link

D. EPA-ICPOES.xls ................................................................................................................................................. link

E. EPA-ICPMS.xls.................................................................................................................................................... link

F. U isotopes Ketterer.pdf ........................................................................................................................................ link
1

Geochemical Data from Groundwater at the Proposed 

Dewey Burdock Uranium In-Situ Recovery Mine, 

Edgemont, South Dakota

By Raymond H. Johnson

Abstract

This report releases groundwater geochemistry data from samples that were collected in 

June 2011 at the Dewey Burdock proposed uranium in-situ recovery site near Edgemont, South 

Dakota. The sampling and analytical methods are summarized, and all of the data, including quality 

assurance/quality control information are provided in data tables.

Introduction

Powertech Uranium Corporation (Powertech) has proposed to mine uranium at the Dewey

Burdock site using in-situ recovery methods. The Dewey Burdock site is located in the 

southwestern region of the Black Hills of South Dakota (fig. 1). The uranium recovery license 

application by Powertech to the United States Nuclear Regulatory Commission (NRC) is publicly 

available and contains background information about the site along with technical details and 

baseline sampling data. The NRC application Web site is: http://www.nrc.gov/materials/uraniumrecovery/license-apps/dewey-burdock.html (with detailed application documents under the 

“application documents” link). A brief summary of the site history is provided by Powertech at

http://www.powertechuranium.com/s/DeweyBurdock.asp.

At the Dewey Burdock site, uranium occurs as roll-front ore bodies in several sandstone 

units of the Inyan Kara Group of Early Cretaceous Age. The Late Jurassic Morrison Formation 

underlies the Inyan Kara Group. In the vicinity of the mine site, the Inyan Kara Group is comprised 

of the Fall River Formation (upper unit) and the Lakota Formation (lower unit). The Lakota 

Formation is comprised of the Chilson and the Fuson Members, with the Fuson Member occurring 

between the Fall River and Lakota Formations. Uranium roll-front deposits occur in the Fall River 

Formation and the Chilson Member of the Lakota Formation. Other geologic units of interest for 

the study area are the surface alluvial aquifers and the Unkpapa aquifer underlying the Morrison 

Formation. The well location symbols on the maps in figures 2 through 4 are color coded to 

indicate the aquifer screened interval for each well.

The U.S. Geological Survey (USGS) collected 28 groundwater samples from monitoring 

wells (figs. 2 through 4) in and around the Dewey Burdock site during the last two weeks of June 

2011. This sampling was completed with funding from the U.S. Environmental Protection Agency 

(USEPA) Region 8’s Regional Applied Research Effort (RARE) Program. USEPA is responsible 

for evaluating the site through its underground injection control program 
2

(http://www.epa.gov/region8/water/uic) and Powertech has submitted a separate permit application 

to USEPA (see documentation in a link within the above USEPA Web site). While these new 

samples provide data on major ion and metal concentrations that overlap with Powertech’s baseline 

sampling, the main intent of this sampling is to get isotopic measurements that will be used to 

better understand the hydrogeologic system. 

Sampling Methods

Groundwater samples were collected using either a peristaltic pump (used in shallow wells), 

a bailer (used when access problems were encountered), installed pump, or using a low-flow,

submersible, stainless steel pump. Many of the wells are under artesian pressure and are flowing, 

with a valve assembly attached at the surface to control the flow (fig. 5). This same valve assembly 

was present in all wells with installed pumps. For wells with installed pumps or that were flowing, 

approximately three well bore volumes were purged prior to sampling. 

A peristaltic pump was used in shallow 2-inch diameter wells where the water table was 

less than 27 feet below the top of the well casing. The sample tubing was placed approximately 1 

foot above the bottom of the well and groundwater was purged until field parameters stabilized, 

which usually occurred within a few minutes. New polyethylene sample tubing was used for each 

well. 

The submersible pump was a Geotech SS Geosub model by Geotech Environmental. The 

stainless pump was placed at approximately 50 feet below the water table and a drop tube 

assembling was lowered ahead of the pump to the bottom of the well 

(http://www.geotechenv.com/pdf/ground_water_sampling_equipment/ss_geosub_wcontroller.pdf ). 

The tubing and pump were then pulled back so the intake was one foot from the bottom of the well. 

This allowed for direct sampling within the well screen and within the active groundwater flow 

zone using micropurge sampling. Groundwater was purged until field parameters stabilized, which 

usually occurred within a few minutes and was generally a function of meter stabilization (partially 

because of added pumping pressure) and not a change in groundwater conditions. New 

polyethylene sample tubing was used for each well. 

A bailer was used in well 680 when the installed pump in the well failed after having 

purged three casing volumes. The well head was opened and the bailer was used to get water within 

the casing. A bailer was also used for well NBA, a newly installed well with a 2-inch diameter 

casing where the water table was below the limit of the peristaltic pump. A bailer was used to purge 

the well of three casing volumes before sampling. Sampling was completed using the peristaltic 

pump with new sample tubing to get water out of the bailer and through an inline filter.

For all samples, groundwater sampling was completed through a “T-valve” apparatus that 

split the flow into a flow through cell for field parameter measurement and a separate line for 

filling sample bottles (fig. 6). The sample line included an inline 0.45 micron filter that was used 

for all bottles except for tritium (sample NBA was filtered for tritium also, as the sediment load was 

high). Field parameter measurements of pH, specific conductance, temperature, dissolved oxygen, 

and oxidation/reduction potential were all done using a YSI 556 multiparameter meter that screwed 

directly into the flow through cell (see cover photograph), thereby eliminating any contact with the 

atmosphere. 

Nine aliquots of water provided samples for (1) cations/metals, (2) 234U/238U activity ratios, 

(3) anions, (4) dissolved organic carbon, (5) iron pairs (Fe3+/Fe2+), (6) tritium, (7) stable isotopes 

(

18O and deuterium), (8) sulfur isotopes (34S), and (9) carbon isotopes (14C). Details on bottle type, 
3

bottle size, rinsing, filtration, and preservative methods are listed in table 1. Any acids used for 

preservatives were ultra pure and made specifically for sample preservation. For bottles that were 

rinsed, rinsing was completed three times prior to filling the bottle.

Table 1. Bottle type and size, rinsing, filtration, and preservation for analytes.

[HDPE, high density polyethylene; mL, milliliter; L, liter; μm, micrometer; HNO3, nitric acid; HPO4, phosphoric acid; 

HCl, hydrochloric acid]

Analytes Bottle Type Bottle 

Size Rinsing Filtration Preservative

Cations and 

dissolved 

metals

HDPE 30 mL New bottle, rinse 

with sample water 0.45-μm 5 drops HNO3 or 

to pH less than 2

234U/238U HDPE 30 mL New bottles, rinse 

with sample water 0.45-μm 5 drops HNO3 or to pH less than 2

Anions HDPE 30 mL New bottle, rinse 

with sample water 0.45-μm Keep cool

Dissolved 

organic carbon Amber glass 125 mL

New bottles, 

cleaned and burned, 

do not rinse with 

sample water

0.45-μm

5 drops HPO4 or 

to pH less than 2, 

keep cool

Dissolved iron 

species

Amber 

polyethylene 60 mL New bottle, rinse 

with sample water 0.45-μm

5 drops HCl or to 

pH less than 2, 

keep cool

Tritium HDPE 500 mL New bottles, rinse 

with sample water None None

Water 

Isotopes: 18O 

and Deuterium

Borosilicate 

glass 60 mL New bottles, rinse 

with sample water 0.45-μm None

34S HDPE 125 mL New bottles, rinse 

with sample water 0.45-μm

2 drops of HNO3

to reduce biotic 

activity

14C Amber glass 1 L

New bottles, 

cleaned and burned, 

do not rinse with 

sample water

0.45-μm Keep cool

Analytical Methods

This section describes the analytical procedures completed on each of the nine water sample 

aliquots. The cations/metals sample was analyzed at the USEPA (Ada, Oklahoma) and at the USGS

laboratories (Denver, Colorado). USEPA analyses were made using inductively coupled plasma –

optical emission spectrometry (ICP-OES, Perkin-Elmer Optima 3300DV) using EPA Method 200.7 

and inductively coupled plasma – mass spectrometry (ICP-MS, PQExcell, Thermo Elemental)

using USEPA Method 6020. USGS analyses were made using ICP-MS at the USGS Mineral 

Resources Laboratory (Denver, Colorado) following the method described in Lamothe and others 

(2002).
4

The 234U/238U activity ratios were analyzed by Michael Ketterer at the Northern Arizona 

University in Flagstaff, Arizona using a sector field Thermo X Series II quadrupole ICP-MS unit. 

Details on the analytical method can be found in file Appendix F.

Dissolved anions were analyzed by the USEPA laboratories (Ada, Oklahoma) using 

capillary electrophoresis with ultraviolent (UV) detection (USEPA Method 6500). Capillary ion 

electrophoresis is a free-zone electrophoretic technique optimized for the analysis of anions with 

molecular weights of less than 200 grams/mole. The anions migrate and are separated according to 

their mobility in the electrolyte when an electrical field is applied through the open tubular fused 

silica capillary.

Concentrations of dissolved inorganic carbon were measured by the USEPA laboratories 

(Ada, Oklahoma) with a Dohrmann DC-80 Carbon Analyzer (USEPA Method 9060A). Iron pairs 

(Fe3+/Fe2+) were completed by David Fey at the USGS Mineral Resources Laboratory (Denver, 

Colorado) using the ferrozine method for iron species discussed in Bangthanh To and others 

(1999). Tritium analyses were completed by Robert Michel at the USGS Isotope Laboratory in 

Menlo Park, California using liquid scintillation counting with a detection limit of approximately 

0.6 tritium units (TU) (similar to USEPA method 906.0). Oxygen- and hydrogen-isotopic ratios of 

water were analyzed using a high temperature conversion elemental analyzer linked to a continuous 

flow isotope ratio mass spectrometer (Finnigan Delta plus XP). These analyses followed the 

methods presented by Lu (2009). Sulfur isotopes (34S) were analyzed by Christopher Eastoe at the 

University of Arizona following the method of Coleman and Moore (1978). Additional analytical 

procedures for that laboratory can be found at

http://www.geo.arizona.edu/research/iso_analytical.html.

Data

All of the resulting data are provided in table 2. Sample identification numbers in table 2

match the well identification numbers used in Powertech permit application documents. Original 

labeling included “B” and “D” in the sample name for ease of sample identification (found in 

appendix files) by area, “B” for Burdock and “D” for Dewey, but were not included in the final 

data table (table 2). 

The samples in table 2 have been organized by categories to reflect geologic units that the 

wells are screened in along with general area locations. These are purely initial categories used by 

the author for later use in interpretations. 

Quality Assurance/Quality Control

For all USEPA solution measurements, quality assurance tests involved duplicate samples,

blanks, sample matrix spikes, calibration check standards, and second-source quality control 

samples. Data for the laboratory quality assurance/quality control (QA/QC) checks are included in 

the original data that can be found in the appendixes. Uranium isotope data also included internal 

laboratory checks that can be found in Appendix F. All other laboratories used typical internal 

reference standards for the appropriate analyses and QA/QC information is available upon request. 

No internal laboratory QA/QC issues were found.

In addition to the internal laboratory checks, three duplicate samples and five blanks were 

submitted as part of the QA/QC process. Data from these duplicates and blanks are reported in 

table 3. No QA/QC issues were found in any of the duplicate samples. Blanks for all of the 

different sampling conditions are represented (Geosub pump, peristaltic pump, and bailer 
5

sampling). For metals, cations, and anions, a few blanks did show values above the detection limits, 

but generally these values were well below any sample results. Only one blank had an iron 

concentration that was high enough compared to the groundwater samples to be of concern. Iron in 

the bailer blank (B-VS4) was 3.72 μg/L, which is likely because of incomplete cleaning of the 

bailer. Cleaning the bailer was difficult because of limited access inside the bailer in addition to 

sample NBA (well sampled prior to blank) having a high silt content. As a result, any measured 

iron values below 4 μg/L, may not be accurate, especially for samples using a bailer. Sample data 

were not blank corrected. 

Acknowledgments

Funding from the US EPA made this data collection possible. Special thanks go to Richard 

Wilkin (USEPA, Ada, Oklahoma) for managing the USEPA contract and organizing the sample 

submittals to the appropriate USEPA laboratories. We are grateful for well access provided by 

individual land owners and through arrangements made by Powertech. Powertech employees, 

Wyatt Van Eaton and Mike Beshore provided invaluable assistance in accessing the wells and 

assisting with equipment logistics. Facilities for equipment storage and a convenient staging area 

were provided by Mark Hollenbeck. In addition, the groundwater sampling included assistance 

from Brian Zimmerman, Andrew Mahan, Valois Shea, Tanya Gallegos, and John Horton.

References Cited

Bangthanh To, T., Nordstrom, D.K., Cunningham, K.M., Ball, J.W., and McCleskey, R.B., 1999, 

New method for the direct determination of dissolved Fe(III) concentration in acid mine 

waters: Environmental Science and Technology, v. 33, p. 807–813.

Coleman, M. L., and Moore, M.P., 1978, Direct reduction of sulfates to sulfur dioxide for isotopic 

analysis. Analaytical Chemistry, v. 50, p. 1594-1598.

Lamothe, P.J., Meier, A.L., and Wilson, S.A., 2002, The determination of forty-four elements in 

aqueous samples by inductively coupled plasma–mass spectrometry, in Taggart, J.E., ed., chap. 

H, Analytical methods for chemical analysis of geologic and other materials, U.S. Geological 

Survey: U.S. Geological Survey Open-File Report 02-223-H, 11 p., available at 

http://pubs.usgs.gov/of/2002/ofr-02-0223/H21&23OFR99-151_M.pdf.

Lu, F.H., 2009, Online high-precision δ2

H and δ18O analysis in water by pyrolysis: Rapid 

Communications in Mass Spectrometry, v. 23, p. 3144-3150.
6

Figure 1. Location of study area.
7

Figure 2. Satellite imagery overlain with monitoring well locations. Labels indicate well identification 

number. White boxes indicate location of expanded views for figures 3 and 4.
8

Figure 3. Expanded view of Dewey area. Labels indicate well identification number.
9

Figure 4. Expanded view of Burdock area. Labels indicate well identification number.
10

Figure 5. Typical wellhead control valves.
11

Figure 6. “T-valve” used for sampling.