Interpretation of the push and pull tracer test data in heterogeneous aquifers

Heterogeneous aquifer characterization is a key step in both quantitative and qualitative groundwater studies. The high cost required in the flow field characterization and the small budget usually available make accurate and effective models for data analysis and information acquisition necessary.

We present here a methodology for the interpretation of the tracer test data widely used in the aquifer characterization; in particular we focus on the push and pull test, the latter is commonly adopted for the investigation of the hydrogeological and chemical parameters of aquifers.

Our stochastic methodology through the direct simulation of transport within a heterogeneous formation, allows to characterize the main geostatistical properties of the flow field and the main transport parameters. The model conceptualization is a stratified formation with isotropic log-hydraulic conductivity normally distributed; the integral scale in the vertical direction is I_Y,V while the horizontal integral scale is unbounded I_Y,H=∞ The flow field is assumed to be steady state and driven by the pumping rate. Transport is simulated by a Lagrangian procedure considering advection dispersion and equilibrium adsorption reaction. The results show that adopting different test setup many aquifer parameters can be obtained. The promising methodology was tested with field data from literature, showing encouraging results.