CP-1994-10
Ground-water tracing with injected helium.
Gupta, S.K., L. Stephen Lau, and Philip S. Moravcik
Helium has several characteristics that make it attractive for use as a tracer in hydrological studies. Two types of experiments were conducted to investigate applicability of helium as a tracer of groundwater movement. The experiments included studies using laboratory sand and soil columns and field groundwater tracing in a basaltic aquifer. A water helium analyzer comprised of a thin quartz glass membrane and diode ion pump (making use of the preferential permeation of helium through the quartz glass into an evacuated space) was developed and used for the experiments. Study results demonstrated that breakthrough curves of specific conductance and helium were similar under saturated conditions. In the unsaturated sand/soil columns, breakthrough curves of helium were retarded relative to specific conductance, reducing the usefulness of helium as a tracer.