Embodiments of the present invention provide a sediment bed passive flux meter (SBPFM) and associated methods. In one embodiment, an SBPFM is provided. The SBPFM comprises a casing. The casing comprises an intake portion, an exhaust portion, and an intermediate portion between the intake and exhaust portions. The SBPFM further comprises a permeable sock positioned within the intermediate portion of the casing and a sorptive matrix positioned within the sock. The sorptive matrix is impregnated with one or more tracers. The SBPFM is configured to passively intercept, but not retain, groundwater flow passing through the SBPFM from the intake portion to the exhaust portion.