ABSTRACT
Tracer tests at El Berrocal site were aimed to hydrological characterization, instrumentation development and data base generation for modeling purposes. They were placed at two borehole arrays in fractured granite. Tracers were exclusively non-sorbing although great differences were observed among some of them during the recovery periods. Performance of the tests was carried out with newly developed instrumentation which proved to be robust and reliable working with downhole electronics. Interpretation of the tests included several conceptual models. Those that resulted in more realistic prediction capabilities took into account the heterogeneity of the system, matrix diffusion and the hydrogeological context at local scale. Simple analytical models proved to be helpful but with limited prediction capabilities. Including in the model features and processes which are often neglected in normal permeability media, such as the bore presence or the transient flow effects during the tracer injection, was of utmost importance.
