Uranium in Groundwater

Science Center Objects

The Issue: Groundwater monitoring in northeastern Washington State has shown elevated levels of naturally occurring uranium in several community water systems and in private wells. A better understanding of the occurrence of uranium in groundwater along with outreach products that communicate the risk to area residents are important in order to reduce uranium exposure, protect from the toxic kidney effects of uranium, and reduce the risk of cancer.

How USGS will help: In close cooperation with water-resource agencies and stakeholders, the USGS completed two phases of work related to uranium in groundwater. Phase one consisted of a preliminary assessment of naturally occurring uranium in groundwater, which relied on existing information and limited sampling. In phase two, the USGS designed several outreach products to communicate the risk of naturally occurring uranium in well water, and to provide information about water testing and treatment options.

Barn located within the Little Pend Oreille Wildlife Refuge

Barn located within the Little Pend Oreille Wildlife Refuge, Stevens County, Washington

(Credit: Sue Kahle, USGS. Public domain.)

Problem - Most rural residents in northeastern Washington State rely on private wells as their source of drinking water. Although water from most wells in the area has concentrations of uranium below the drinking water health standard, the amount of uranium in area groundwater varies greatly and has been measured at nearly 40 times the health standard. Some well owners are unaware of the presence of uranium in area groundwater and many private wells go untested.

Objectives - Phase One: Conduct a reconnaissance study of northeastern Washington State involving: (1) compiling geologic, hydrogeologic, and radionuclide information, (2) preparing maps of available data sets in order to identify areas with elevated levels of uranium and to evaluate data gaps, (3) obtaining uranium-concentration data for selected wells in areas without data, and (4) publishing a document summarizing available data, data gaps, and suggestions for further study. Phase Two: Produce informational community outreach products developed in partnership with stakeholders. Products are designed to inform residents about the risks posed by uranium in area groundwater, and to provide guidance for well owners on testing and treatment options for uranium in their drinking water.

Relevance and Benefits - This study contributes to the goals of the USGS strategic science direction, identifying environmental risk to public health in America, as identified and described in the Strategic Science Plan of the USGS (U.S. Geological Survey, 2007). The study addresses groundwater quality which is a priority issue for both the USGS Water Mission Area and the USGS Washington Water Science Center. The project also serves the USGS mission by advancing the science of water-resource assessments of the region, by providing data useful to multiple parties, and by furnishing information that will help protect human health.

Approach - Phase One: Obtain and review documents and data sets from local, regional, state, and national agencies, and convert selected data sets to digital coverages for data analysis purposes. Collect limited new data for private wells in areas where uranium-concentration data are generally lacking. Publish a USGS Scientific Investigations Map to report on the current knowledge and data gaps regarding uranium in groundwater in northeastern Washington State. Phase Two:  Design and distribute several informational community outreach products, including (1) a USGS factsheet which summarizes the phase one study, (2) a Geonarrative with similar content to reach the online community, (3) a one-page flyer with basic information about uranium as well as testing and treatment options, and (4) a PowerPoint presentation that provides a summary of the issue and explains key concepts at the high school level.

Naturally Occurring Uranium in Groundwater in Northeastern Washington State, PowerPoint presentation prepared by Sarah B. Dunn, U.S. Geological Survey, May 2020

Is there uranium in your drinking water? Flyer prepared by Sarah B. Dunn, U.S. Geological Survey, May 2020