Tracer experiments using bromide ion and two bacteriophages during soil aquifer treatment studies

Abstract

The fate and transport of a conservative and two bacteriophage tracers during Soil Aquifer Treatment (SAT) has been examined. A 12 foot x 12 foot mini-basin containing seven stainless steel suction samplers ranging in depth from 1 to 20 feet below land surface was constructed in an existing recharge basin. Bromide ion and MS-2 and PRD-1 virus tracers were introduced into the mini-basin during recharge of secondary effluent during three of nine flooding cycles in order to aid in interpreting transport processes and to determine the presence of preferred-flow channels. High infiltration rates and discontinuous impeding layers resulted in 150 feet of horizontal transport. Preferential-flow channels were observed in both the vertical and horizontal directions. Less removal of bacteriophage MS-2 (hydrophilic, 28 nm dia) was observed at all depths compared to PRD-1 (hydrophobic, 62 nm dia). Results suggest that the fate of the virus transport in sandy alluvium is determined by the size and hydrophobicity of the viral particles, the quality of the percolating fluid, and composition of the soils.