Evaluation and application of dye tracing in karst terrain

As ground water becomes increasingly important as a source of water in the United States, reliable information on the hydrological characteristics of carbonate aquifers must be obtained in order to develop them intelligently. Various tracers have been used in the past to determine if two or more points are connected hydrologically. Today there exists a number of excellent dye tracers and tracer methods have been developed in unconsolidated and clastic aquifers for determining hydrological characteristics. This paper reviews the various dye tracers and methods which might be applied in a carbonate karst terrain us3.ng wells as injection and sampling points. Fluorescein, Rhodamine, and Pontacyl Pink are evaluated. Effective porosities of the Gasconade, Roubidoux, and Jefferson City Formations were determined from field samples to estimate the amount of water which might be stored and transmitted through these rocks. In field investigations, salt, fluorescein, and Rhodamine were used as tracers during pumping tests at three sites. No background fluorescene was detected in any of the well or spring samples. No connection was established between any wells because none of the tracers placed in the injection wells was detected at any of the observation wells. A point dilution curve was obtained for one injection well