Possible mobility of residuals of ammonium nitrate fuel oil blasting agents in desert soil and ground water

Abstract

Field and laboratory studies were conducted to assess the effect, if any, of residuals of ammonium nitrate fuel oil (ANFO) detonation on ground-water quality of a portion of Planet Valley, Arizona. Preliminary soil samples were taken near detonation sites to characterize background levels of NO₃-N. Laboratory experiments were performed to determine the mass of NO₃-N removed from soils exposed and unexposed to the products of ANFO detonation. Ground-water samples were taken from eight wells to monitor changes of NO₃-N. Preliminary soil samples showed that considerable NO₃-N existed at some depths near detonation sites. Laboratory study showed no significant difference between the mass of NO₃-N leached from exposed soil and that eluted from unexposed surface soil. Analyses of water samples from all wells, except one, showed NO₃-N levels to he similar to background values. The source of NO₃-N which occurred in the one well, either natural soil NO₃-N or NO₃-N introduced as a residual of ANFO detonation, could not be determined. The effect of ANFO residuals on water quality was no more than would occur if natural soil NO₃-N were leached to the ground water.