EA: Upgrade of a Mass Spectrometric System for Noble Gases

Ensuring environmental sustainability is one of the United Nation’s millennium development goals and this includes reducing the population without sustainable access to safe drinking water. Groundwater is the largest reservoir of usable fresh water on earth, but rates of movement and fluxes are typically small, extraordinarily variable, and poorly defined for most aquifers. Age dating groundwater has proven to be an exceptional tool for characterizing groundwater systems from both water resources and water quality perspectives. The age of a groundwater sample collected at a point in space contains information regarding the upstream velocity field and thus serves as a critical calibration target for numerical models of groundwater flow. Mean groundwater ages are related to the ratio of storage to recharge, two of the most fundamental parameters for evaluating water resources. A key goal of this project is to promote a better understanding of groundwater flow system (vulnerability to contamination and sustainability of groundwater resources) using environmental tracers. The equipment provided by this grant (sector-field and quadrupole mass spectrometers) will facilitate the continued characterization of groundwater systems by the more than 140 institutions which have previously utilized the noble gas laboratory at the University of Utah. The proposed project is to upgrade the noble gas laboratory by replacing a 30-year-old mass spectrometer in support of hydrologic and geologic research. Noble gases dissolved in water have been used for age dating groundwater, provenance studies, and thermometry along with surface exposure dating of minerals. This mass spectrometer acquisition will support hydrologic studies, such as those previously completed like characterization associated hazardous waste disposal in clay-rich aquitards, the evaluation of cap rock seals associated with carbon capture and storage (CCS), thermometry and age dating associated with aquifer characterization, and the transit time distribution of baseflow and streams. It would also indirectly support geomorphic studies that utilize exposure age dating. The major broader impact of this grant supports water sample analysis to partner institutions and to train visiting scientists at the noble gas laboratory. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.