A mercury control strategy that warrants serious considerations by plants burning high- or low-sulfur coals is using a wet electrostatic precipitator (ESP). Mercury can be removed as particulate matter directly if it is in water-soluble oxide form, and directly-after being adsorbed into a adsorbent-if it is in elemental form. Wet ESP technology has proven capable of controlling sub-micron particulate emissions and acid mist from boilers firing mid- to high-sulfur coals. now the same results appear possible at plants burning low-sulfur subbituminous coals and lignite-if wet ESP technology is deployed after a dry ESP, in lieu of baghouse.