Study of transient constant rate pumping tests in heterogeneous media

Evaluation of constant rate pumping tests using drawdown data at observation wells with Jacob's method results often in similar transmissivity — and in strongly varying storativity — estimates. As an example we present field data from the migration experiment at the Grimsel Test Site (Switzerland). Numerical simulations and analytical developments are presented to show that the observed behaviour is an interpretation problem inherent to Jacob's method when used for the analysis of pumping tests in heterogeneous formations.