City of Corsicana - Lake Halbert WTP - Executive Summary |
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The City of Corsicana (herein referred to as the City) owns and operates two municipal water treatment plants and two municipal wastewater treatment plants in Corsicana, Navarro County, Texas. Each of the water treatment plants uses chlorination to treat and disinfect surface water. The wastewater treatment plants use both chlorine and sulfur dioxide to disinfect treated effluent wastewater. The City has reviewed its obligations under EPA's Risk Management Program Rule (RMP Rule, Section 112(r) of the Clean Air Act). In response to these requirements, the City notes that there are two obligations incumbent on the operations at its facilities: 1. '112(r)(1) - Purpose and General Duty Clause - The essence of the general duty clause is that an owner/operator that stores and uses hazardous chemicals in any quantity has a fundamental obligation to ensure a safe operation, and to have plans in place in the event of an accident to appropriately manage the situation. The City takes this o bligation very seriously, and intends to be not only a good neighbor but also a leader in community safety and emergency preparedness. 2. Risk Management Plan - The City operates two water treatment facilities that store and use chlorine in excess of thresholds specified in the RMP Rule. Additionally, the City operates two wastewater treatment plants that store and use both chlorine and sulfur dioxide in excess of the RMP Rule thresholds. Even prior to the promulgation of the RMP Rule, the City management has been very aware of the potential hazards posed by storage and use of chlorine and sulfur dioxide, and has established programs to prevent any accidental releases and training for emergency response in the event of a release. These programs are documented and described in this Risk Management Plan. The purpose of the chlorination process at each facility is to disinfect both surface water and effluent treated wastewater. The purpose of the sulfur dioxide treatment process at ea ch wastewater treatment facility is to remove any chlorine residual prior to discharge into natural waterways. Each process chemical is delivered as a compressed gas in one-ton cylinders, and there are typically three to six cylinders at each plant at any one time. For planning purposes, the City has considered the impact of a sudden release of the entire contents of one cylinder within a 10-minute period of time. Very conservative (i.e., "worst case") assumptions about possible weather conditions and a predictive model indicate a potential radius of impact extending to 3.0 miles for the chlorination process and 3.1 miles for the sulfonation process. A consideration of this radius has been incorporated into our notification and emergency response planning. The City also considered the impact of a more likely release, based on operational history and most likely hazard analysis. This analysis suggest that the largest release of chlorine that could realistically be experienced by t he facility results in a radius of impact of between 0.1 and 0.2 miles (i.e., having potentially few off-site impacts). The City has implemented safety precautions to prevent and mitigate any chlorine or sulfur dioxide gaseous releases. In addition to maintenance, training, and inspection procedures, the City has active monitoring and alarm systems at select locations that will detect a release and sound a local alarm. The City has coordinated with local emergency responders including the Corsicana Fire Department. The City management is committed to: 7 Preventing accidents; 7 Training employees in correct response procedures in the event of an accident; 7 Providing leadership to the community with respect to emergency preparedness; 7 Addressing any citizen concerns by fully explaining potential hazards associated with facility operations and all steps being taken to prevent and mitigate accidents; and 7 Being a good corporate citizen of Navarro County. With these objectives in min d, this Risk Management Plan provides information about the management of the risks associated with the chlorination and sulfonation process, but more importantly stresses a commitment to ensuring a safe operation for employees, visitors, and the surrounding community. |