Neutrino sensitivity and backgroung rejection of the Auger Observatory

The Auger Observatory will be the largest air shower array ever built. This array of water Cherenkov pools offers the unique advantage of a large acceptance at very low zenith angle. Auger is therefore very well suited for study- ing horizontal air showers and in particular neutrino induced showers. In this short lecture the main characteristics of the acceptance will be given as well as the means by which neu- trino induced showers can be disentangled from the large hadronic horizontal shower background. We will also present recent results on the possible detection of tau lepton induced shower from charge current interaction in the ground sur- rounding the Auger array.