A forced‐gradient experiment on solute transport in the Borden aquifer: 2. Transport and dispersion of the conservative tracer

Abstract

Conservative tracer transport was monitored at 42 multilevel points and a partially penetrating (PP) well during a forced‐gradient test in the Borden aquifer. Point breakthrough curves were adequately simulated by the advection‐dispersion model indicating negligible or nondetectable physical nonequilibrium effects. Relative hydraulic conductivities estimated from fitted flow rates for each point varied by almost an order of magnitude, similar to the variation previously reported for permeameter analyses of samples from a nearby core transect. Longitudinal dispersivities were 16 cm for the PP well data and ranged from approximately 1 to 11 cm for the point data. These values are within the range of local dispersivities reported for point data in previous tracer tests at the Borden site and other experiments. Composite layer simulations of the PP well utilizing flow and dispersivity estimates from multilevel data matched the general shape of the observed response but not its position.