Abstract: A method and apparatus for treating nuisance odor streams is provided. One embodiment of the invention is directed to a method and apparatus in which deodorizing chemical agents are applied to an evaporative reaction pack situated within a gas chamber having an air stream running therethrough. The evaporative reaction pack provides a reaction zone within which the chemical agent is evaporated to facilitate a gas--gas or vapor phase interaction between the chemical agent and odoriferous compounds contained in the air stream. Another aspect of the present invention relates to a method and apparatus for batch processing of sewage treatment agents within a wet well to prevent the formation of undesired compounds. In one embodiment, a predetermined amount of chemical agent, sufficient for treating the amount of sewage that the well can hold, is added to an evacuated wet well in coordination with the pumping of sewage from the wet well.