Assessing of the effect of physical heterogeneity on single well tracer tests using imaging experiments

摘要

Single well forced gradient tracer tests can be used to assess aquifer properties for natural attenuation and remediation design. Measurements of aquifer properties monitored in the well are depth-averaged and therefore may misrepresent or fail to identify important flow and mass flux paths. Such spatial information is critical for remedial system design. UV imaging tests were undertaken in a pseudo 2-D tank filled with glass beads, with a centrally positioned slotted well screen. Fluorescent tracer migration during dipole flow tracer tests (DFTTs) and push-pull tests (PPTs) were examined under isotropic and simple layered conditions. Results show that small variations in hydraulic conductivity significantly affect tracer flow. For DFTTs these produce discernable differences in breakthrough curves, which can be used to help identify important hydrogeological features.