Ottawa Water Treatment Plant - Executive Summary |
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Release prevention and emergency response policies Personnel at this City of Ottawa (City) facility take a very active approach in maintaining and improving chemical safety. This facility complies with industry-standard requirements for water treatment plants that use chlorine in ton containers. The policy at this facility is to adhere to all applicable federal, state, and local laws. If an emergency were to occur, the policy is to notify the City of Ottawa Fire Department and request that they respond to the emergency. Facility and regulated substance This facility is a water treatment plant located in Ottawa, Kansas. It employs a series of physical and chemical treatment operations that include: pretreatment, aeration, softening, stabilization, filtration, and disinfection processes. The covered process includes the use of chlorine chemicals. This chemical is used in the disinfection and chlorination process that is used to destroy pathogenic microorganisms. The major pla nt process unit involved in disinfection is the chlorination system. The chlorine is provided through truck-delivered one-ton containers and the maximum intended inventory is 4,000 pounds. Chlorine is drawn from the containers in gaseous form and fed through chlorinators into the water streams. 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. The alternative release scenario is based on a methodical analysis of accident history, hazard review, experience at other similar company facilities, and industry experience. The result is that a failure of one of the fusible plugs due to a dropping accident during unloading was chosen as the scenario. The assumed leak occurs outside of any containment and chlorine gas flows through a 5/ 16-inch opening. Leak duration is assumed to be 60 minutes to allow for response activities that include the installation of a B repair kit. Because the release would be directly to atmosphere, no enclosure factors were considered. No other mitigative 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 the endpoint for the chlorine worst-case release is 1.3 miles and for the alternative release, the distance is 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. The chlorine system was designed, installed, and maintained in accordance with state and local laws. To achieve and maintain this compliance, the City has in place procedur al and technological safeguards. The procedural safeguards include an employee training program and operating and maintenance procedures for those employees involved in operating the covered processes. The technological safeguards include controls, sensors, alarms, relief valves, and industry standard systems. All of these serve to prevent unintended releases of chlorine, or at least minimize the effects of a release. Five-year accident history 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 Ottawa Fire Department is the primary responder. City employees handle incidental releases of chlorine and are trained and equipped to do so. The emergency action plan includes causes and effects of emergencies, reducing system vulnerability and eme rgency planning activities. The plan discusses mutual aid agreements with both the police and fire departments. 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 upon observation of a potential hazard, are always considered carefully for implementation. This 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 recent hazard review are under consideration. |