Twelve odor sources were identified around the plant. Each source was fitted with a cover system of either high strength coated fabric or aluminum diamond plate panels designed to capture off-gases which were piped to the individual Carbtrol activated carbon Air Purification Systems. These systems are designed for flow rates from 90 to 1000 CFM. Each Carbtrol Air Purification System consists of a canister containing from 170 to 250 lbs of activated carbon and an attached blower installed in a noise attenuation housing. These Air Purification Systems have the advantage of being relatively light (less than 600#), small space requirements (less than 4 ft. square), easy to change out, and can be located adjacent to the odor source.