Mankato Wastewater Treatment Plant - Executive Summary |
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The Mankato Wastewater Treatment Plant has developed this Risk Management Plan because of the amount of chlorine and sulfur dioxide that is kept on-site. Chlorine is used as a disinfectant in wastewater treatment and sulfur dioxide is used to dechlorinate the wastewater effluent stream. Up to eight one-ton chlorine cylinders and eight on-ton sulfur dioxide cylinders are stored at the plant. A Risk Management Plan is required by EPA rules (40 CFR 68) when a facility stores greater than 2,500 pounds of chlorine and 5,000 pounds of sulfur dioxide at any one time. An analysis of a worst case release scenario, as defined by the EPA rules and a more likely alternate release scenario, selected from trade association guidance, was conducted and is documented in this plan. The alternate case release scenario indicates that a radius of one fifth of a mile would be included in the distance to toxic endpoint. The Wastewater Treatment Plant operates and maintains the chlorination and dechlori nation system under its Process Safety Management (PSM) program, which was developed several years ago to comply with OSHA Standard 29 CFR 1910.119. The PSM program is designed to operate and maintain the system and the equipment in a manner that will reduce the possibility of a chlorine or sulfur dioxide release. In the event of a chlorine or sulfur dioxide release, the plant has coordinated emergency response efforts with the Mankato Department of Public Safety. The Wasewater Treatment Plant is currently undergoing modifications which should eliminate the use of chlorine and sulfur dioxide within the next year. |