Wastewater Treatment Plant - Executive Summary |
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Release prevention and emergency response policies Personnel at this facility are active in maintaining and improving chemical safety. This facility complies with industry-standard requirements for wastewater treatment plants that use chlorine in ton containers. The Board of Public Work's policy is to adhere to all applicable federal, state, and local laws. If an emergency were to occur, our policy is to notify the Hannibal Fire Department and request that they respond to the emergency. Facility and regulated substance This facility is a wastewater treatment plant located in Hannibal, Missouri. The facility employs a series of physical, biological, and chemical treatment operations that include: screening, grit removal, activated sludge treatment, sedimentation, aerobic digestion, and disinfection. The covered process is the storage and feed of chlorine for algae control and for disinfection of the wastewater. The chlorine is stored in and fed from truck-delivered one-ton cont ainers and the maximum intended inventory at the facility is 16,000 pounds. Worst-case and alternative release scenarios The worst-case release scenario involves the largest chlorine-containing vessel in the system, the ton container. It can contain up to 2,000 pounds of chlorine. The rule for worst-case release analysis assumes all of the contents are released in 10 minutes. No passive mitigation was considered and no active mitigation could be considered. The alternative release scenario was based on an analysis of accident history, hazard review, experience at other similar company facilities, and industry experience. The alternative release scenario involved the partial release of the contents of one ton container of chlorine through a break or disconnection of the flexible tubing connecting the container to the manifold header. Because the release would be in a building where the ton containers are stored, an enclosure mitigation factor was considered. No other mitigativ e measures were considered. For both analyses, the EPA's Risk Management Program Guidance for Wastewater Treatment Plants was used. The results were verified using RMP*Comp, which is based on the formulae in the guidance document. The distance to endpoint for the chlorine worst-case release was 1.3 miles and for the alternative release, the distance was 0.1 mile. Accidental release prevention program The facility's prevention program complies with the corresponding sections of EPA's 40 CFR part 68 accident prevention program rule for program level 2 processes and applicable state and local codes and regulations. The chlorine system was designed, installed, and maintained in accordance with state and local laws and industry codes. To achieve and maintain this compliance, the Board of Public Works has in place many procedural and technological safeguards. The procedural safeguards include an employee training program and operating and maintenance procedures for those employees inv olved in operating the covered processes. The technological safeguards include controls, sensors, alarms, relief valves, and other safety systems. All of these serve to prevent unintended releases of chlorine and, failing that, to minimize the effects of a release. Five-year accident history In the last five years, this facility has not had an accident, involving chlorine, that caused deaths, injuries, property or environmental damage, evacuations, or shelterings in place. Emergency response program The facility has a written emergency action plan that is coordinated with local emergency responders. The Hannibal Fire Department is the primary responder. Board of Public Works employees handle incidental releases of chlorine and are trained and equipped to do so. The emergency action plan includes emergency situation identification, procedures for reporting emergencies, evacuation, system shutdown, and responder notification. The plan also addresses the interaction with the cit y fire department. Planned changes to improve safety The maintenance and improvement of safety is an ongoing job at this facility. Safety training takes place throughout the year. Safety-related recommendations from employees, whether made during formal sessions like the hazard review or made upon observation of a potential hazard, are always considered carefully for implementation. This feedback process is continuous and, even at times when no major process changes are anticipated, existing safety systems and procedures are fine-tuned as a matter of course. Currently, the recommendations made during the hazard review are under consideration. |