Water infiltration and percolation at the University of Arizona radioactive waste burial site, Pinal County, Arizona

The University of Arizona produces different types of radioactively contaminated waste. It is shipped to a burial site located on the Oracle Agricultural Center in Pinal County, Arizona and disposed of in shallow pits. This study dealt with water movement at the disposal site. Monitoring of water movement through young pits was accomplished with a neutron probe. It was found that due to slumping and cracking of the pit cap, the younger pits were very susceptible to greater than normal water infiltration. Further data were gathered around the older pits by deep soil sampling for tritium activity. Water fluxes and travel times to the major aquifer were calculated from these data. Estimates of travel times range from 40 to 230,000 years to reach the principal aquifer at 150 m.hydrology collectio