U.S. Geological Survey Utah Water Science Center
Ryan Rowland is a Hydrologist with the U.S. Geological Survey Utah Water Science Center (UTWSC) in West Valley City, Utah. During his 15+ year career, he has participated in and lead numerous ground and surface water studies on topics including sulfate reduction in a zero valence iron reactive barrier for uranium sequestration in shallow groundwater, installation and operation of four water quality and weather platforms for hydrodynamic modeling and evaporation estimates for Lake Mead, Nevada and Arizona, uranium transport near an active uranium mill in southeastern Utah, and more recent studies on Great Salt Lake nutrient mass balance and deep brine layer dynamics. He graduated from the University of Utah in 1997 with a B.S. degree in Environmental Earth Science and is currently the Water Quality Field Specialist at the UTWSC.
Title: Assessment of Deep Brine Layer Extent and Geochemistry Prior To and After Opening of a New Causeway Bridge, Great Salt Lake, Utah
Wednesday, May 9th, 1:25 PM
Abstract: Closure of the east and west culverts and recent (Dec. 1, 2016) opening of a new bridge on the Great Salt Lake causeway presents a unique opportunity to study deep brine layer (DBL) dynamics and its impact on south arm (Carrington and Gilbert Bays) biological and geochemical processes. The USGS, in cooperation with the Utah Department of Natural Resources, Division of Forestry, Fire, and State Lands, and the University of Utah, Department of Geology and Geophysics, is working on a project to 1) quantify the timing of initiation and evolution of anoxia in the DBL after opening of the new bridge; 2) characterize vertical development of the DBL in the water column at fine time scale resolution; and 3) determine the timing of initiation and evolution of sulfate reduction and mercury methylation in the DBL. Preliminary results of the study confirmed 1) the absence of the DBL prior to opening the new bridge; 2) persistent anoxia in deep water in Carrington Bay prior to and after re-establishment of the DBL; 3) short-term development of anoxic conditions at sites south of Carrington Bay before DBL re-establishment; and 4) re-establishment of the DBL in much of the south arm by December 2017. The loss and subsequent return of the DBL had direct impact on the concentrations of total and methyl mercury in water samples collected in the south arm for the project that will be discussed by Dr. Bill Johnson, University of Utah.