QUANTIFYING NUTRIENT AND TRACE METAL INPUT TO UTAH LAKE FROM THE OREM WASTEWATER TREATMENT EFFLUENT

Utah Lake, one of the largest freshwater bodies west of Mississippi River, is critical for regional agriculture irrigation and recreation. However, anthropogenic activities, such as effluent from the wastewater treatment plants, fertilizer/manure application in agricultural lands, mining discharge, and urban storm water runoff to the lake, have severely impacted the water quality and led to elevated trace metal and nutrient levels in the lake. In this project, we took samples biweekly from three transects along the discharge channel at an interval of 100 meters from Orem Wastewater Treatment Plant discharge point toward Utah Lake. Two water and sediment samples were taken along each transect and the samples were analyzed for As, Pb, and Cd concentrations using the Inductively Coupled Plasma Mass Spectrometry. Additionally, the water samples were analyzed for nitrate and phosphate concentrations using a CHEMetrics V-2000 Photometer. The ground water sample taken from the wastewater treatment plant was used as our control value. The objectives of this project are to 1) quantify the amount of nutrient and trace metals released to Utah Lake from the Orem Wastewater Treatment Plant effluent; 2) investigate the temporal and spatial variations of trace metals and nutrient concentrations along the discharge channel; 3) evaluate the efficiency of wetlands along the discharge channel with respect to nutrient and trace metal removal. The results from this project will provide both the general public and Orem city with quantitative information on how much nutrient and metals of interest is discharged daily to Utah Lake from the Orem Wastewater Treatment Plant, and how effective the wetlands are in nutrient and trace metal removal. In addition, the results will allow us to propose a plan to the wastewater treatment plant on how to utilize the existing wetlands between the effluent discharge point and the lake to maximize wetland nutrient and trace metal removal efficiency. Finally, the results from this project can be used by six other wastewater treatment plants around Utah Lake to improve the lake water quality.