Harry Reid Center for Environmental Studies
Chemistry Division

HRC >> Chemistry >> Groundwater Research

Groundwater Chemistry Research

Understanding the groundwater flow system is of fundamental importance at the Nevada Test Site (NTS) in the event that radionuclides from the underground nuclear testing program come in contact with the ground waters and are subsequently solubilized and potentially transported in the flow system. In the event of such a scenario, a thorough comprehension of ground water flow on the NTS would be imperative to properly remediate the system and to assure that the local environment, which includes Ash Meadows National Wildlife Refuge and Death Valley National Park, would not be compromised.

The HRC has extensive experience in ground water analytical chemistry and has demonstrated that ground water geochemistry can be used to characterize ground water and identify sources of different ground waters. The current "fingerprinting" research is a three part effort to characterize ground water on the NTS as to its source aquifer, decipher the history of movement of the ground water and quantify the percentages of mixing between ground waters of various sources. This will be accomplished by analyzing the ground water for approximately 55 chemical constituents, conduct leaching studies on core materials and analyze the host aquifer rock for the same 55 elements.

Chemical Tracer Research

Groundwater tracers are solutes dissolved in or carried by ground water to delineate flow pathways. Tracers provide information on direction and speed of water movement and that of contaminants that might be conveyed by the water. Tracers can also be used to measure effective porosity, hydraulic conductivity, dispersivity and solute distribution coefficients. They can be naturally occurring compounds or elements, or they can be completely foreign to the environment. The latter is generally preferred. For most applications tracers should be conservative, that is, move at the same rate as the water and not sorb to aquifer materials. Aquifer materials are generally negatively charged, so anionic tracers will not adsorb and will move with the water.

The HRC has supported the U.S. Geological Survey and Los Alamos National Laboratory research teams in tracer testing at the Yucca Mountain Site in Nevada. In addition, HRC supported Sandia National Laboratory at the Waste Isolation Pilot Project in New Mexico and is looking forward to working with the U.S. Department of Energy in tracer tests at the Nevada Test Site.

Tested springs

• Ash Meadows Springs
• Muddy River Springs
• Nevada Test Site Springs and Wells
• Oasis Valley Springs
• Pahranagat Valley Springs
• Spring Mountain Springs