Heavy Metals in the Great Salt Lake, Utah

Abstract

The Great Salt Lake is a closed basin that drains a large part of northern Utah and parts of Wyoming and Idaho. The lake is a repository of all inorganic materials both suspended and dissolved that are carried by the streams flowing into the lake. Some of the salts are concentrated by several orders of magnitude in the lake over the natural concentration in the inflowing streams. It is the objective of this paper to determine if several heavy metals, specifically copper, zinc, cadmium, mercury, lead, and arsenic are also concentrating in the lake and to determine the behavior of these metals in the lake. A major obstacle to the study was the difficulty in analyzing the trace elements in the concentrated lake brines due to interference from the salts in the water. Methods for analyzing trace elements in brines were developed and are explained in detail in the paper. It was found that the concentrations of both total and dissolved metals in the lake are very low, and in the case of copper, zinc, and cadmium, are lower than the concentrations in the inflowing streams. It appears that the metals are precipitating along with clays, organics, and carbonates into the bottom sediments of the lake where anaerobic bacterial action is immobilizing the metals.