OCCURRENCE AND MOBILITY OF URANIUM AND OTHER ELEMENTS IN THE GRAND CANYON SPRINGS

The proposed research proffers the use of multiple chemical parameters, coupled with multivariate statistical techniques to identify a signature of anthropogenic disturbance in spring water within the Grand Canyon. Due to past mining activity within the Grand Canyon, an increase in local mining claims near the Canyon, and increased pumping of the regional aquifer (Redwall-Muav), the Grand Canyon springs may be in danger of contamination, reduced flows, or possibly extinction.

Previous investigators report uranium concentrations exceeding the Environmental Protection Agency’s (EPA) standard for clean drinking water in several of the Grand Canyon springs. These springs are generally within close proximity to historical uranium mines or their associated ore bodies (breccia pipes). The breccia pipes act as conduits for groundwater recharge. Horn Spring emanates from the Redwall-Muav aquifer just below the historical Orphan Mine on the South Rim of the Grand Canyon and has exceeded uranium concentrations for EPA standards. In addition, other geochemical constituents of Horn Spring are anomalous to proximal springs emanating from the same aquifer.

The objective is to evaluate the groundwater mobility of uranium and other elements appearing in Horn Spring and select Canyon springs, by using multivariate geochemical and statistical analytical techniques. The hypothesis to be tested is that elevated uranium concentrations in selected Canyon springs are the result of enhanced preferential flow and dissolution in breccia pipes affected by past mining activities. This work will address the question of hydrologic and chemical alteration of groundwater by mining activity and the potential resultant degradation of springs.