The physical behavior and geologic control of radon in mountain streams

Abstract

Radon distribution ratio determinations in an all-water system were made. They checked very closely with those done by Kofler in 1913. The distribution of radon in stream waters and related springs was investigated in the Wasatch Mountains adjacent to Salt Lake City, Utah, and in a part of the Weber River near Ogden, Utah. The radon distribution in the stream waters studied forms a definite pattern which is dependent upon the local influx Of relatively large amounts of radon-bearing ground water into the stream, and, in turn, the ability of the stream to lose its radon to the atmosphere through turbulence. The ability of the stream to lose its radon is governed largely by the gradient and rate of flow of the stream and the nature of the stream channel, and tends to reach an equilibrium value of less than one micro-micro Curie per liter. This loss of radon generally occurs as an exponential function with respect to distance of stream flow. The slope of the function varies with different streams. The stream waters investigated contain from one limit of the sensitivity of theinstrument to about 450 micro-micro Curies of radon per liter. The radon content of spring waters is generally higher than that of stream waters. The large radon contents mark the areas of ground water influx into the stream, although, in most cases, no spring activity in these areas was observed. The high-radon anomalies can usually be related to definite stratigraphic horizons or structural features. The amount of ground water being added to the stream can be estimated in some cases by radon measurements of stream waters and related springs. Almost complete disequilibrium occurs between radon and its parent radium in stream and spring waters in this area.