The measurements of the magnetic resonance (MR) of the transition from normal to anomalous hydrodynamic dispersion due to biological activity in porous media were discussed. It was found that on porous media transport dynamics, fractional advection-diffusion equations provided models for the measured impact of biofilm growth. A transition in the hydrodynamic dispersion dynamics, which can be modeled as a transition from normal to anomalous transport, was generated by the biofilm growth in porous media. The strong impact of the biofilm on flow dynamics coupled with innovations in MR technology for inexpensive low magnetic field applications provided the concept of online biofilm assays for filtration and bioreactor technology.