Navajo WaterGIS

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 relational database.

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 analysis.

[1] Breit, G. (2007). Selected USGS Water Samples for the Bidahochi Area of the Southern AUM Region of the Navajo Nation [Point Shapefile]. U.S. Geological Survey.

[2] 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.

[3] Church Rock Uranium Monitoring Project (CRUMP). (2003). [Point Shapefile].

[4] Credo, J., Torkelson, J., Rock, T., & Ingram, J. C. (2019). Quantification of Elemental Contaminants in Unregulated Water across Western Navajo Nation. International Journal of Environmental Research and Public Health, 16(15), 2727. https://doi.org/10.3390/ijerph16152727

[5] Hoover, J., Coker, E., Barney, Y., Shuey, C., & Lewis, J. (2018). Spatial 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. https://doi.org/10.1016/j.scitotenv.2018.02.288

[6] Hoover, J., Erdei, E., Nash, J., & Gonzales, M. (2019). A Review of Metal Exposure Studies Conducted in the Rural Southwestern and Mountain West Region of the United States. Current Epidemiology Reports, 6(1), 34–49. https://doi.org/10.1007/s40471-019-0182-3

[7] 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. https://doi.org/10.1007/s12403-016-0226-6

[8] Lewis, J., Hoover, J., & MacKenzie, D. (2017). Mining and Environmental Health Disparities in Native American Communities. Current Environmental Health Reports, 4(2), 130–141. https://doi.org/10.1007/s40572-017-0140-5

[9] Ingram, J. C., Jones, L., Credo, J., & Rock, T. (2020). Uranium and arsenic unregulated water issues on Navajo lands. Journal of Vacuum Science & Technology A, 38(3), 031003. https://doi.org/10.1116/1.5142283

[10] Jones, L., Credo, J., Parnell, R., & Ingram, J. C. (2020). Dissolved Uranium and Arsenic in Unregulated Groundwater Sources – Western Navajo Nation. Journal of Contemporary Water Research & Education, 169(1), 27–43. https://doi.org/10.1111/j.1936-704X.2020.03330.x

[11] 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.

[12] 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.

[13] Rock, T. (2017). Developing Policy around Uranium Contamination on the Navajo Nation Using Traditional Ecological Knowledge [Ph.D., Northern Arizona University]. http://search.proquest.com/docview/1994442794/abstract/FEF64979FA21433APQ/1

[14] Southwest Resource Information Center (SRIC). (1988). Puerco River Education Project Data (1985-1988).

[15] U.S. Army Corps of Engineers. (2000). U.S. Army Corps Of Engineers Water Sampling [Point Shapefile]. U.S. Environmental Protection Agency.

[16] U.S. Environmental Protection Agency. (n.d.). Superfund Technical Assessment and Response Team (START).

[17] U.S. Environmental Protection Agency. (2008). Navajo Nation Drinking Water Source Sampling 2008.

[18] U.S. Environmental Protection Agency. (2009). Navajo Nation Unregulated Wells Sampling Results.

[19] U.S. Office of Navajo and Hopi Indian Relocation (1997). Effects of Uranium-mining Releases on Ground-water Quality in the Puerco River Basin, Arizona and New Mexico. U.S. Department of the Interior, U.S. Geological Survey.

[20] Water Resources of the United States—National Water Information System (NWIS) Mapper. (n.d.). Retrieved March 12, 2021, from https://maps.waterdata.usgs.gov/mapper/index.html

[21] Wirt, L., Van Metre, P. C., & Favor, B. (1991). Historical Water-Quality 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)).

Well Use: Domestic Livestock Municipal Other Unknown

Data Dashboard

Red dashed line on histograms indicates primary maximum contaminant level (MCL)
Yellow dashed line indicates secondary MCL.
More information on primary and secondary water contaminants can be found here.

Data Table

Well No.	Chapter	Agency	Lat	Long	As	Ca	Ra_Total	U

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Data Dashboard

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Data Table