City of Kingsport - Wastewater Treatment Plant - Executive Summary |
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The City of Kingsport's Wastewater Treatment Plant has a comprehensive risk management program in place. Trained plant personnel acting in conjunction with the Fire Department's Hazardous Materials Response Team ensures the local community of optimum attention to accident prevention and hazard consequence response and mitigation. Chlorine is used as a disinfectant in the wastewater treatment process. The plant stores up to 10 one-ton cylinders or 20,000 pounds of chlorine at any given time, exceeding the threshold of 2,500 pounds established by the Environmental Protection Agency (EPA), thereby, qualifying this facility to comply with the elements of EPA's Risk Management Plan (RMP). The worst-case chlorine release scenario involves the rupture of a one-ton cylinder, whereby all 2,000 pounds of gaseous chlorine are released at a rate of 200 pounds per minute for 10 minutes. Other pre-determined factors influencing the release are a wind speed of 1.5 meters per second and an "F" at mospheric stability class. Using EPA's Offsite Consequence Analysis (OCA) guidelines for urban topography, the resultant plume has a radius of 2.6 miles or a circle of influence 5.2 miles in diameter. Under this scenario, certain public and environmental receptors could be affected, depending upon wind direction, including schools, residences, one hospital, recreation areas, major commercial, office and industrial areas, and a bird sanctuary. The alternative or most-likely case scenario involves the failure of a transfer pipe from 1 chlorine cylinder, a typical arrangement during normal operating conditions. Again using EPA's OCA guidance, 317 pounds of gaseous chlorine would be release at a maximum average sustained rate of 10.5 pounds per minute for 60 minutes. Also, the wind speed for this scenario would be 3.0 meters per second with a "D" atmospheric stability class. The resultant distance to the endpoint of the radius would be 0.5 miles for an urban setting or a circle of in fluence 1 mile in diameter. The receptors affected by this release, depending upon wind direction, would be schools, residences, major commercial and industial areas, and a bird sanctuary. The Wastewater Treatment Plant is in compliance with the Occupational Safety and Health Administration's (OSHA) Process Safety Management (PSM) rule, a complimentary regulation to EPA's RMP. The elements of the PSM program that constitute the RMP's accidental release prevention program are described as follows: Management System - establishment of a management team headed by the Environmental Manager responsible for developing, implementing, and integrating the risk management program; Employee Participation Plan - reflects the involvement of employees necessary to implement the RMP program; Process Safety Information - the compilation of written material to enable the employees involved in process operation to identify and understand the hazards posed by the use of chlorine and how it relates to the technology and equipment used in the process; Operating Procedures - development and implementation of written operating procedures that provide clear instructions for safely conducting activities involved in each process; Training - each employee presently or to be involved in operating a process is trained in an overview of the process and in the operating procedures including emphasis on the specific safety and health hazards, emergency operations including shutdown, and safe work practices applicable to the employee's job tasks; Contractors - those performing maintenance or repair, turnaround, major renovation, or specialty work on or adjacent to a covered process, shall be knowledgeable, trained and responsible in matters concerning PSM as it pertains to chlorine; Mechanical Integrity - development and implementation of a maintenance plan, inspection and testing procedures, deficiency correction plan, and a quality assurance program designed to ensure that equipment used to p rocess, store or handle chlorine is designed, constructed, installed and maintained to minimize the risk of a hazardous chemical release; Hot Work Permits - to document that fire prevention and protection requirements are observed; Management of Change - development and implementation of procedures to manage changes in process chemicals, technology, equipment, procedures and changes to facilities that affect a covered process; Incident Investigation - development and implementation of procedures necessary to thoroughly investigate each incident which resulted in, or could reasonably have resulted in a significant release of chlorine; Compliance Audits - provides assurance that compliance has been evaluated at least every three years, verifying that the PSM procedures and practices are adequate, observed and reported. The City of Kingsport's Wastewater Treatment Plant has not had a reportable incident during the past five years. The development and implementation of the PSM and RMP p rograms have increased employee awareness to the hazards of chlorine and the processes and procedures necessary to minimize the probability of a release and, if an event should occur, minimize the associated risks. Continued improvement in the integrity of both programs will allow employees and the community to feel secure that all precautions are being taken to ensure their health and safety. The Emergency Response Program (ERP) has been tailored to specifically address the consequences of a chlorine release from this facility. Employees at the Wastewater Treatment Plant have been trained in Personal Protective Equipment and Respiratory Protection as defined by OSHA regulations. This enables them to safely handle changing out of chlorine cylinders and respond to incidental releases of chlorine sometimes experienced during routine procedures or taking immediate actions to prevent a situation from escalating into a significant release. In the event of a significant release, a chlor ine detector automatically activates an alarm and ventillation system. Plant personnel will immediately notify the City's Fire Department (Hazardous Materials Response Team) via Central Dispatch, which will promptly respond to the incident. Plant personnel will immediately evacuate the area according to procedure, with a designated coordinator(s) to rendezvous with the Hazmat Team at a predetermined site outside the affected perimeter to discuss proper response procedures. The Hazmat Team, fully trained in hazard response and communication, will represent the Fire Department as the lead agency determined by the Kingsport Emergency Preparedness Plan. They also have access to a preprogrammed computer located in their van that enables them to predict the nature of the site-specific release. This was accomplished, in part, as the result of a pre-plan of this facility by the Hazmat Subcommittee of the Local Emergency Preparedness Council. With this information available, the responder s can efficiently mitigate the risks associated with the release and inform the affected community about proper response action. Training has been conducted, resulting in increased experience and knowledge in responding to a significant release scenario at this site. Continued training of personnel, updating of RMP and PSM programs, and mock response demonstrations will serve to assure the public, personnel and responders that their health and safety are of highest priority should a significant release of chlorine occur at the City of Kingsport's Wastewater Treatment Plant. This will continue to be our philosophy as we seek to alleviate this potential hazard through the installation of mitigation or control equipment or using different methods such as ultraviolet technology. |