News Release, Kansas Geological Survey, April 29, 2009
LAWRENCE--Water specialists at the Kansas Geological Survey, based at the University of Kansas, have received a grant from the U.S. Environmental Protection Agency (EPA) to examine fluctuating levels of uranium and other radiation-emitting elements in the Arkansas River in southwestern Kansas.
The $49,000 grant will allow Survey researchers Don Whittemore and Elizabeth Petroske to determine when and where the uranium and other elements may exceed water-quality standards as river flows change due to precipitation and human activities in the upper Arkansas River basin.
The upper Arkansas River basin includes the section of the river that runs from the Colorado border to Great Bend.
"Based on the limited data we now have, the concentration of uranium in the Arkansas River entering Kansas and within southwest Kansas is known to be greater at times than the drinking water standards during low flows," said Whittemore. "This project will provide additional data to determine the level of uranium and radionuclides in different flow conditions."
Radionuclides, or radioactive isotopes, are atoms with unstable nuclei that emit radiation as they decay. The uranium and other radionuclides in the Arkansas River occur naturally--the uranium mainly leached from shales in eastern Colorado--but the amount and concentration of each at any given time or place is influenced by rises and falls in the river and the sources of its water.
The drinking-water standard for uranium, or maximum contamination level (MCL), is 30 parts per billion. Uranium has been measured as high as 65 MCL in the river during periods of low flow.
Under the U.S. Clean Water Act, states are required to identify bodies of water that don't always meet water-quality standards for a specific constituent, such as uranium, and submit a list of impaired waters to the EPA.
For the current study, water samples will be collected from the river at a number of locations during different flow conditions and seasons then analyzed for uranium and other dissolved substances.
The project is being coordinated with the Kansas Department of Health and Environment (KDHE), and the Southwest Groundwater Management District No. 3 will help collect samples.
KDHE--the state agency responsible for regulating public water supply systems--and others will be able to use the results to identify potential problems and improve water quality.
"Knowledge of the uranium and radionuclide levels in the river will be useful in developing water management strategies in Kansas that will lower their impact not only on the river but on the ground-water quality of such sources as the High Plains aquifer underlying the river," Whittemore said.