Basic equations of flow and transport in porous media

Bioremediation strategies are applied to decrease or eliminate contaminants that are distributed in the subsurface. For a remediation exercise to be successful, it must build on the response of the subsurface fluids to changes in pressure that might cause immobile fluids to be mobilized or fluids moving along one flow path to be diverted to another. If a cleanup effort is to be conducted, in situ procedures must be employed that will allow the bacteria to reach the contaminant with appropriate nutrients for the degradation reaction to occur. The flow fields must be manipulated to allow juxtaposition of bacteria and the target contaminants. If a cleanup activity is to be on site following a pump and treat strategy, some knowledge of the expected response of the fluid reservoir to pumping stresses must be employed. This is important, not only to ensure that the pumping will bring the contaminants to the treatment facility, but also to assess how much contaminant will remain trapped in the soil over the short term, but providing a long-term pollution threat.