Abstract: A method of processing peat for use in treating a contaminated aqueous solution, especially storm water runoff entering a sewer system. The method includes mixing raw peat with heated sulfuric acid to produce a slurry. The slurry is dried and then mixed with a binder medium to produce an aggregate material. The aggregate material is extruded to form a plurality of pellets. The plurality of pellets are then baked in an oven at a temperature in the range of approximately 900-1000 degree F. Peat processed in accordance with the present invention serves as both an ion exchange material as well as an organic retention material. A filter canister for maintaining pelletized peat is also disclosed.