Power plants often use more than one device to stop pollutants from escaping
smokestacks. Baghouses are filtration structures such as the one seen here that
have been retrofitted to many power plants nationwide. They work by catching
fine particulates—tiny clumps of soot, dirt, and chemicals that can
damage lungs and collect in the atmosphere, creating smog. Baghouses function
as massive vacuum cleaners. They are lined with many fabric filter "bags,"
which plant engineers periodically clean or replace, carting away the
particulates they collect.