PAINTSVILLE WWTP - Executive Summary |
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The Paintsville City Utilities accidental release prevention policy involves a preparatory approach, which involves the community safety and welfare. In conjunction with the Johnson County LEPC, Kentucky EM, Paintsville Fire Department we strive to achieve all applicable policies and procedures of the U.S. Environmental Protection Agency (EPA). The Johnson County Mitigation Plan involves the county as a whole and is tailored to each point source within our community. This plan is in compliance with the EPA Emergency Response Program requirements. The Paintsville Waste Water Treatment Plant (WWTP) was constructed in 1962 and upgraded in 1986 to a 0.99 MGD plant. The WWTP serves the Paintsville, Kentucky area with waste water collection and treatment. Chlorine is used at the facility for disinfection of the effluent flow from the plant to the Levisa Fork of the Big Sandy River. The WWTP, as a point source, includes the use of Chlorine stored in three each one-ton containers for a total of 6,000 pounds of chemical. The facility is operated by three personnel during the week days and one person to check operation on the weekends. If any trouble alarms are encountered additional personnel are available for after hour calls. The offsite consequences analysis includes consideration of two chlorine release scenarios identified as "worst case release" and "alternative scenario". The first scenario is defined by EPA, which states that "the owner or operator shall assume that the ...maximum quantity in the largest vessel... is released as a gas over 10 minutes", due to an unspecified failure. The alternative scenario is defined as "more likely to occur than the worst case release scenario". The worst case release scenario at the Paintsville WWTP involves a failure in a one-ton container releasing a total of 2,000 pounds of Chlorine. The dense gas plume can travel 5.4 miles until the toxic end point is obtained given a 10 minute release, urban conditions, F stabi lity, and wind speed of 1.5 meters per second. The actual number of residents affected by this worst case release scenario would depend upon the physical direction of the wind at the given time of the accidental release from the point source. However, the Paintsville WWTP being the origin, an estimated residential population of 14,795 would be encompassed by a radius of 2.8 miles from the origin source of release. The vulnerable zone as established with the Technical Guidance for Hazards Analysis, Emergency Planning for Extremely Hazardous Substances indicate under the TAB Q-7 Covered Facilities that the use of a 10 mile radius encompassing the point source. This plan is currently on file with the Kentucky Division of Emergency Management-Area 9 Manager. This 10 mile radius given a release of 2,000 pounds of Chlorine could affect a portion of the 45,770 estimated residential population depending on wind direction vector. Under this plan actions taken will be for the protection of the emergency response workers on site and the populated area off site. These actions will depend upon the chemical, the amount of chemical released, weather conditions, and other hazards involved ( such as fire). If the incident is of a short duration 30 minutes or less in-place sheltering is generally applicable and may have limited application for releases over a period of time in excess of one hour. Should the release duration exceed 30 minutes notification of the emergency alert system, cable override, police and fire departments loud speaker system, and notification of the news and radio media may be used to notify the population in the affected area calling for evacuation of the threatened area. Evacuation routes and emergency shelters are set forth in the Johnson County Hazard Mitigation Plan. Local hospitals are involved with the Johnson County LEPC and are trained in the emergency decontamination of Chlorine. The general Paintsville WWTP accidental release prevention p rogram is based on the following elements: *High level of training of the operators and off site personnel *Preventive maintenance program *Use of state-of-the-art process and safety equipment *Performance of a hazard review of equipment procedures *Implementation of an auditing and inspection program as follow up to training programs Chemical-specific prevention steps include availability and annual fit testing for the use of self-contained breathing apparatus (SCBA), awareness of the hazardous and toxic properties of Chlorine, and the presence of chlorine leak detection equipment, warning lights, and audible alarms. The operators and rescue teams are trained in the use of a 2,000 pound Chlorine Institute "B" Repair Kit and know the use for each item in the kit. Paintsville City Utilities is in compliance with the OSHA - PSM rule and this plan. The initial release of chlorine in the first 10 minutes would be 20% of the container capacity (e.g., 20% of 2,000 pounds equals 400 pounds ). This would hold true for holes in the container of less than 3/8". After the initial release of chlorine the opening begins the formation of liquid-droplet aerosols and depending upon the ambient temperature will cause freeze / thaw cycles to be seen around the fracture of the container. If the release where to occur in the winter months the freeze / thaw cycles would be less frequent than in the summer months. This information was obtained at the last Chlorine Training Seminar and was stated to be the consensus of the Chlorine Institute and other Chlorine providers in the Industry. Based upon this quantity of released product the following alternative release scenario involves the rupture of the flexible connection (pigtail) connected to a one-ton container in which 400 pounds of Chlorine gas escaped thru a 3/8" pigtail. At the release rate of 40 pounds per minute the distance to the toxic end point would be 2.5 mile from the design characteristics set forth in the EPA-RMP in structions. An estimated population of 14,795 would be encompassed by a radius of 2.8 miles from the origin source of the release. Actuation of the Chlorine leak detection equipment is an active mitigation measure considered as well as the use of remote vacuum type chlorinators reduces the significantly the amount of chlorine released in the case of a pigtail rupture. No accidental releases of Chlorine have occurred at the Paintsville Waste Water Treatment Plant in the past five years. Further training of hazmat response teams and training with the local fire department on Chlorine emergency response " mock disaster scenario" does provide helpful information in the response and coordination of different departments. By the use of equipment and personnel available along with continuing education programs we provide a high level of safety to our employees as well as the community. The safety and welfare of our community is very important to Paintsville City Utilities. |