Bristol Water Treatment Plant - Executive Summary |
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Release prevention and emergency response policies Personnel at this City of Bristol (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 Bristol City Fire Department and request that they respond to the emergency. Facility and regulated substance This facility is a water treatment plant located in Bristol, Connecticut. The plant employs a series of physical and chemical treatment operations that include: rapid mixing, three-stage flocculation, sedimentation, filtration, and storage in reservoirs. Chlorine is the regulated substance used to disinfect the water prior to storage. The covered process includes the storage and feed of chlorine. The chlorine is provided throu gh truck-delivered one-ton containers and the maximum intended inventory at the facility is 6,500 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 mitigative measures are considered for this analysis. The alternative release scenario is based on a methodical analysis of accident history, process hazard analysis, experience at other similar company facilities, and industry experience. The alternative release scenario involves a chlorine release from a small crack in the container at a valve connection. It is assumed that responders can stop the leak within one hour of its initiation. The leak is assumed to occur outside so no enclosure factor was considered. No other mitigative measures were considered. For both anal yses, 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 scenario is 1.3 miles and for the alternative release scenario, 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 3 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 procedural 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 sensors, alarms, and manual shutoffs. A ll 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 Bristol Fire Department is the primary responder. City employees can handle incidental releases of chlorine. The emergency action plan includes disaster and emergency situation identification, escape procedures, procedures to account for all personnel after an emergency evacuation, and rescue and medical duties. 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 lik e the process hazard analysis 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 process hazard analysis are under consideration. |