“…The first tritium observed in the pumping well, located 91 m (299 ft) from the test cavity, was not observed until after 900 days (2 ½ years) of pumping (Bourcier et al, 1999). This demonstrates that the native aquifer material has an extremely low hydraulic conductivity (even under a forced gradient) and supports the suggested theory of a very slow contaminant migration away from the shot cavity.…”