Tracer tests involve the injection of an inert solution, or tracer, into an existing flow field via a borehole or a well. Tracer tests are often desirable because they are passive-type tests and do not place unnatural stress conditions on the flow system.
The dilution rate of the tracer at the injection well or its time of travel to another well can be used to calculate the water velocity and ultimately the permeability. Detection of the tracer, or concentration measurements, can be made by either manual or probe sampling. Commonly used tracers are radioisotopes, salt solutions and fluorescent dyes.
