LAND-USE IMPACTS ON TRACE METAL CONCENTRATIONS IN UPLAND, WETLAND, AND SURFACE WATERS OF UTAH LAKE

Utah Lake has a history of human impacts resulting in the accumulation of trace metals (TMs) in the soils around the lake. Studies of Utah Lake water and saturated soils have been evaluated before; however, these do not give a complete picture of the human impact on upland soils as some of the pollutants may never enter the water due to soil characteristics and inherent chemical properties of TMs. Anthropogenic impacts can be better understood by evaluating TMs in the unsaturated upland soils. Elevated concentrations of TMs in the environment pose potential hazards to the ecosystem and people. Comparison of TMs in saturated wetland and unsaturated upland soils as related to anthropogenic sources will be completed. This investigation will analyze the types and concentration of TMs and their mobility. Sixty-four core samples, in replicates of three, in saturated and unsaturated soils from eight sites representing residential, industrial, agricultural, and recently developed area (New Dev) and established (Mid Dev) areas were collected, and water samples obtained where applicable. Water, sediment, and soil samples were dried, sieved, acid digested, and analyzed in the ICP-OES for TM (As, Pb, Cu, Cr, Cd, and Zn) content. Acidity, redox potential, temperature, dissolved oxygen, electroconductivity and salinity will be measured. Preliminary results show that TM concentrations in Upland were higher than those in wetland soils. Cu concentration is 1.7 times higher in Upland agricultural (24.2 ppm) soil compared to wetland soil (14.2ppm). Cr levels in industry and mid Dev is 43.0 ppm and 47 ppm, respectively, in saturated soils they are 23ppm and 21ppm, respectively. Mid Dev and Agriculture are the most impacted land uses having more elevated TM levels on average than the other land uses, with industry being the least impacted. Cd concentrations exceed background levels in New Dev (.97ppm), industry (.57pmm), WWTP (.51ppm), and Mid Dev (.83ppm) in upland soil and was higher in wetland New Dev soil (.97ppm) relative to other land uses and is indicative of anthropogenic impact. The high concentration of TMs in saturated and unsaturated soils indicate that agriculture and Mid Dev land Uses (currently not monitored) play a large role in the contamination of Utah Lake and surrounding areas.