An air quality control system (AQCS) (4) useful for processing a gas stream (DG), such as a flue gas stream emitted from a fossil fuel fired boiler (2), combustion process or the like, for at least partial removal of acidic and like contaminants. The air quality control system (4) includes a plurality of integrated components (12) equipped with both a dry scrubber system (8) and a fabric filter (10). The air quality control system (4) such as described possesses increased “turn down” capabilities thus increasing the efficiency thereof.