Prepared in cooperation with the Bureau of Indian Affairs

234U/238U Isotope Data from Groundwater and Solid-Phase

Leachate Samples near Tuba City Open Dump, 

Tuba City, Arizona

By Raymond H. Johnson, Robert J. Horton, James K. Otton, and Michael K. Ketterer

Open-File Report 2012–1126

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 

For product and ordering information:

World Wide Web: http://www.usgs.gov/pubprod

Telephone: 1-888-ASK-USGS

For more information on the USGS—the Federal source for science about the Earth,

its natural and living resources, natural hazards, and the environment:

World Wide Web: http://www.usgs.gov

Telephone: 1-888-ASK-USGS

Suggested citation: 

Johnson, R.H., Horton, R.J., Otton, J.K., and Ketterer, M.K., 2012, 234U/238U isotope data from groundwater

and solid-phase leachate samples near Tuba City Open Dump, Tuba City, Arizona: U.S. Geological Survey 

Open-File Report 2012–1126, 2 p. 

Any use of trade, product, or firm names is for descriptive purposes only and does not imply 

endorsement by the U.S. Government. 

Although this report is in the public domain, permission must be secured from the individual 

copyright owners to reproduce any copyrighted material contained within this report.
iii

Contents

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

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

Methods......................................................................................................................................................................... 1

Data............................................................................................................................................................................... 2

References Cited........................................................................................................................................................... 2

Appendixes 

A. Ketterer uranium report for June 04, 2009.......................................................................................................... link

B. Ketterer uranium report for May 16, 2011........................................................................................................... link

Table

1. 234U/238U activity ratios and uranium concentrations .......................................................................................... link
234U/238U Isotope Data from Groundwater and 

Solid-Phase Leachate Samples near Tuba City 

Open Dump, Tuba City, Arizona

By Raymond H. Johnson, Robert J. Horton, James K. Otton, and Michael K. Ketterer

Abstract

This report releases 234U/238U isotope data, expressed as activity ratios, and uranium 

concentration data from analyses completed at Northern Arizona University for groundwater and 

solid-phase leachate samples that were collected in and around Tuba City Open Dump, Tuba City, 

Arizona, in 2008. 

Introduction

Groundwater concentration data and solid-phase leachate data were collected for samples 

taken in and around Tuba City Open Dump, Tuba City, Arizona, in 2008. Sample locations, sample 

collection and analytical methods, and previous geochemical results are provided in Johnson and

others (2008). This report releases 234U/238U isotope data, expressed as activity ratios, and uranium 

concentration data that were completed at Northern Arizona University (NAU), Flagstaff, Arizona. 

Activity ratios are not based on the concentration of each isotope, but are a ratio of measured 

radioactivity (in this case, alpha radiation). Table 1 lists the samples that were analyzed for uranium 

activity ratios and uranium concentrations. This is a majority of the samples collected in 2008, but 

not all. All groundwater samples that were analyzed were originally collected in May 2008.

Methods

All of the original sample collection and solid-phase leachate procedures are described in 

Johnson and others (2008). All samples that were provided to NAU were in liquid form and 

included either groundwater samples or solid-phase leachate samples that had been preserved to a 

pH <2 with trace-metal-grade pure nitric acid. The samples were analyzed by inductively coupled

plasma–mass spectrometry (ICP–MS) for 234U/238U activity ratios and uranium concentrations on a 

Thermo X Series II quadrupole ICP–MS unit. Appendixes A and B are the original data files—

appendix A from June 4, 2009, and appendix B from May 16, 2011. These files describe the 

analytical procedures that were used and provide data on quality assurances and quality control. 

The appendix B file was edited to remove data from a different project. Analytical errors associated 

with the 234U/238U activity ratio measurement for each sample are provided as one standard 

deviation from the mean value in table 1. The first set of sample analyses (appendix A, June 4, 

2009) were completed on samples with higher uranium concentrations. The second set of sample 

analyses (appendix B, May 16, 2011) were completed on samples with low uranium concentrations, 

all less than 0.3 micrograms per liter.
2

Data

All of the resulting data are provided in table 1. Sample identification numbers have been 

changed slightly from the original laboratory reports to be consistent with the maps and tables 

provided in Johnson and others (2008). The latitudes and longitudes for each sample are listed in 

table 1 for completeness. Sample categories include direct piezometer or monitoring well samples 

and solid-phase leachate solutions resulting from either deionized water or using a toxiccharacteristic leaching-procedure fluid; see Johnson and others (2008) for more information on 

these category details.

Reference Cited

Johnson, R.H., Otton, J.K., Horton, R.J., Gallegos, T.J., Choate, L.M., and Sullivan, J.E., 2008, 

Geochemical data from analyses of rock, sediment, water, and solid-phase leaching at the Tuba 

City Open Dump, Tuba City, Arizona: U.S. Geological Survey Open-File Report 2008–1374, 10 

p., available at http://pubs.usgs.gov/of/2008/1374.