In the United States the use of unregulated water sources – defined as
sources that do not meet criteria to be
classified as a public water system as defined by the Safe Drinking Water
Act - are used regularly for livestock
watering, agriculture, domestic, and other purposes. Nationally, more than
45 million people rely on unregulated water
sources for drinking water; however, there remains infrastructure
disparities for drinking water access in communities
on Tribal nations. For the Navajo Nation, a sovereign Indigenous nation in
the Southwestern United States, between 7%
and 30% of homes lack plumbing to deliver household drinking water, so
residents are compelled to access other water
sources – regulated and unregulated alike. Previous unregulated water
quality studies on the Navajo Nation were
regionally focused and unsuitable for evaluating water quality trends across
the Navajo Nation, an area that encompasses
more than 71,000 square kilometers in Arizona, New Mexico, and Utah.
Therefore, beginning in 2011 the Community
Environmental Health Program at the University of New Mexico began to
compile existing water quality datasets,
principally for unregulated groundwater sources, in a single geospatial
Researchers at the University of New Mexico Center for Native
Environmental Health Equity Research of the New
Mexico METALS Superfund Research Program, University of
Arizona, Northern Arizona University, and the
Southwest Research and Information Center have compiled a database of
water quality measurements from groundwater
wells on the Navajo Nation using data from the U.S. Geological Survey, U.S.
Army Corps of Engineers, U.S. Centers for Disease Control and
Prevention, Navajo Nation Environmental Protection Agency, and data from
researchers at the University of New Mexico,
Diné College and Northern Arizona University. To date, this data
compilation has been used for publications but has not
been disseminated publicly. The purpose of this website is to facilitate
access to these compiled water quality data.
The application design enables users to view water quality information using
statistical and geospatial tools. Our hope
is that this information will support individual and community decisions
about water use from unregulated sources.
The compiled dataset consists of two primary data tables. The first table is
derived from the Navajo Nation Wells
Database, consisting of more than 5,000 groundwater well records. The second
table includes water quality data from 18
distinct studies collected between 1905 and 2020. The data table includes
845 analytes with the largest number of
observations for trace metals, metalloids, radionuclides, and water
chemistry parameters. The data presented here
represent the publicly available portion of the data compilation. This
tool should not be interpreted as a definitive or
complete record of all wells and water quality results in the
region. In total, the dataset presented here visualized
results for 1,101 water sources.
Some studies recorded uranium concentrations in units of activity
(picocuries per liter), which were converted to mass
per unit volume (μg/L) by dividing activity by 0.67. If multiple
measurements were available per analyte per well, the
maximum concentration was determined for radionuclides, metals, and
metalloids, and the median concentration was
calculated for pH, conductivity, hardness, and other measures of water
chemistry. Measurements that are below the
instrument limit of detection are recorded in the dataset. Values are
imputed as the LOD for visualization purposes. The
downloadable dataset records the LOD and may be used with various imputation
methods for more rigorous statistical
Download the complete data package from the Environmental Data Initiative data portal.
 Breit, G. (2007). Selected USGS Water Samples for the Bidahochi Area of
Southern AUM Region of the Navajo Nation [Point Shapefile]. U.S. Geological
 Centers for Disease Control and Prevention. (2010). Navajo Nation
Unregulated Water Source Sampling Results: October 2009 Sampling Event.
Drinking Water Office, WTR-6, USEPA Region 9.
 Church Rock Uranium Monitoring Project (CRUMP). (2003). [Point
 Credo, J., Torkelson, J., Rock, T., & Ingram, J. C. (2019).
of Elemental Contaminants in Unregulated Water across Western Navajo Nation.
International Journal of Environmental Research and Public Health, 16(15),
 Hoover, J., Coker, E., Barney, Y., Shuey, C., & Lewis, J. (2018).
clustering of metal and metalloid mixtures in unregulated water sources on
the Navajo Nation – Arizona, New Mexico, and Utah, USA. Science of The Total
Environment, 633, 1667–1678.
 Hoover, J., Erdei, E., Nash, J., & Gonzales, M. (2019). A Review of
Exposure Studies Conducted in the Rural Southwestern and Mountain West
Region of the United States. Current Epidemiology Reports, 6(1), 34–49.
 Hoover, J., Gonzales, M., Shuey, C., Barney, Y., & Lewis, J. (2017).
Elevated Arsenic and Uranium Concentrations in Unregulated Water Sources on
the Navajo Nation, USA. Exposure and Health, 9(2), 113–124.
 Lewis, J., Hoover, J., & MacKenzie, D. (2017). Mining and Environmental
Health Disparities in Native American Communities. Current Environmental
Health Reports, 4(2), 130–141.
 Ingram, J. C., Jones, L., Credo, J., & Rock, T. (2020). Uranium and
unregulated water issues on Navajo lands. Journal of Vacuum Science &
Technology A, 38(3), 031003. https://doi.org/10.1116/1.5142283
 Jones, L., Credo, J., Parnell, R., & Ingram, J. C. (2020). Dissolved
and Arsenic in Unregulated Groundwater Sources – Western Navajo Nation.
Journal of Contemporary Water Research & Education, 169(1), 27–43.
 Longsworth, S. A. (1994). Geohydrology and Water Chemistry of Abandoned
Uranium Mines and Radiochemistry of Spoil-material Leachate, Monument Valley
and Cameron Areas, Arizona and Utah. U.S. Geological Survey.
 Navajo Nation Environmental Protection Agency. (2004). Water Sampling
Locations and Results from a Sanitary Assessment of Drinking Water Used by
Navajo Residents Not Connected to Public Water Systems [Point Shapefile].
Navajo Nation Environmental Protection Agency.
 Rock, T. (2017). Developing Policy around Uranium Contamination on the
Navajo Nation Using Traditional Ecological Knowledge [Ph.D., Northern
 Southwest Resource Information Center (SRIC). (1988). Puerco River
Project Data (1985-1988).
 U.S. Army Corps of Engineers. (2000). U.S. Army Corps Of Engineers
Sampling [Point Shapefile]. U.S. Environmental Protection Agency.
 U.S. Environmental Protection Agency. (n.d.). Superfund Technical
and Response Team (START).
 U.S. Environmental Protection Agency. (2008). Navajo Nation Drinking
Source Sampling 2008.
 U.S. Environmental Protection Agency. (2009). Navajo Nation Unregulated
Wells Sampling Results.
 U.S. Office of Navajo and Hopi Indian Relocation (1997). Effects of
Releases on Ground-water Quality in the Puerco River Basin, Arizona and New
Mexico. U.S. Department of the Interior, U.S. Geological Survey.
 Water Resources of the United States—National Water Information System
(NWIS) Mapper. (n.d.). Retrieved March 12, 2021, from
 Wirt, L., Van Metre, P. C., & Favor, B. (1991). Historical
Data, Puerco River Basin, Arizona and New Mexico (Open-File Report 91-196;
Open-File Report). U.S. Geological Survey.
The data presented in this app were compiled by a collaborative and
interdisciplinary team of researchers and students
from the University of Arizona, Northern Arizona University, University of
New Mexico, Montana State University
Billings, the Southwest Research and Information Center, and Navajo Nation
Department of Water Resources. Funding for
the development of this web application was provided by the Agnese Nelms
Haury Program in Environment and Social Justice
at the University of Arizona. Additional funding for the projects that
contributed to the water sample collection and
analysis includes the National Institute for Environmental Health Sciences
(RO1ES014565, R25ES013208, P30ES012072); a
NIGMS ASERT IRACDA postdoctoral fellowship (K12 GM088021); the UNM Center
for Native Environmental Health Equity
Research- A Center of Excellence In Environmental Health Disparities
Research ((1P50ES026102) & USEPA (#83615701);
University of New Mexico METALS Superfund Research Program (1P42ES025589);
and the Navajo Birth Cohort Study (U01
TS000135-05, NBCS/ECHO (1UG3OD023344)).
(firstname.lastname@example.org), App development and data storage, University of
Joseph Hoover, Ph.D. (email@example.com), Data compilation and
database development, Montana State
Potluru (firstname.lastname@example.org), App development, University of New
Dr. Liping Yang
(email@example.com), Ph.D., Project Advisor, University of New
Questions about database content and the compilation process should be
directed to Joseph
Hoover, and questions about the visualization tool and data access should be
to Daniel Beene.