Abstract: A vented baffle system for use in a clarifier tank having a tank bottom, a periphery and a substantially vertical peripheral wall bounding the interior of the tank is formed by a plurality of individual and cooperatively-engageable baffles mounted on the peripheral tank wall. Each baffle includes a panel member that downwardly slopes from the peripheral tank wall toward the interior of the tank and the tank bottom and terminates at a lower edge disposed in space relation above the tank bottom. A first lateral end of the panel member unitarily carries an end bracket securable to the peripheral wall for supporting the panel member in a cantilevered fashion. One or more of the baffles are provided with a relief valve means for venting the pressure in a space formed between the junction of the lower side of the panel member and the peripheral tank wall. The resulting system provides a vented baffle system in which pressure exerted by the build up of gases in the space may be alleviated.