Bioretention is the process of using biological processes and rapid infiltration along with the storage of water to reduce contaminants. A bioretention cell creates an aesthetically pleasing water treatment area to help meet the National Pollutant Discharge Elimination System (NPDES) pollutant standards in, for example, the petroleum producing, refining, and distribution industry, parking lots of shopping centers, and residential homes. Pollutants that may be impacted consist of petroleum products (BTEX, cyclohexane, paraffins, and olefins), metals (cadmium, copper, lead, zinc), and nutrients (nitrogen and phosphorus). Currently there are no design models for bioretention cells that combine the removal of nutrients with infiltration, sorption of metals, and degradation of organic compounds. The model to be discussed will account for these constituents, as well as take into account specific site characteristics like climatic location, area drained, bioretention cell properties, and various loads of pollutants entering. The resulting output from the model would include the dimensions of an infiltration layer, an organic layer, and an anoxic layer, pollutant levels after moving through the cell with associated trapping efficiency, and water quantity leaving the cell. Results of preliminary column tests performed in the laboratory will determine the infiltration and sorption properties of various organic materials.