Fig. 5. Comparison of Br and pentafluorobenzoic acid (PFBA) breakthrough curves as a function of water applied. The blue line represents the Br breakthrough pattern at an irrigation rate of 4.4 mm h^–1 while the black line denotes the PFBA breakthrough pattern at an irrigation rate of 0.89 mm h^–1. The orange line represents the best fit line using the one-dimensional convective–dispersive equation (CDE) of the PFBA data. Solute recoveries and transport fitting are a function of cumulative water applied since tracer application.