A pilot investigation of the behaviour of water in a series of boreholes in the Chalk aquifer using 82Br as tracer is described. The method consists of an instantaneous injection of the tracer into one borehole and subsequent measurement of the tracer concentration in the water abstracted from a neighbouring borehole as a function of time. This paper presents the field data, the results of the data analysis using a simple statistical model to describe the shape of the observed pulse and proposals for the future work deemed necessary to provide hydrological information about the behaviour of groundwater in the Chalk using a two-well pulsed method.