14-Tracer Studies in Evaluation of Dyke as Hydraulic Barrier for Possible Groundwater Pollution

Abstract

Tracer experiments were carried out at two locations within 3 km stretch of dyke, separated by a distance of 1.5 km, where wells on either side of the dyke exist. The strategy adopted was to inject a suitable tracer in a well located on the southern side of the dyke and observe the signal of its arrival over a period of time in wells located on the southern and northern side of the dyke. Iodide in the form of potassium iodide (KI) was selected as tracer for the investigation. Water samples were collected at regular interval of time for 100 days from observation wells and analyzed for conductivity, chloride and iodide concentrations. The results of the analysis indicate that hydraulic continuity exists across the dyke at one location.