Radford Water Treatment Plant - Executive Summary |
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1.0 SOURCE & SUBSTANCE The Radford Water Treatment Plant supplies the City of Radford and areas of Montgomery County with four million gallons of drinking water each day. In order to remove harmful pathogens from water before it is distributed, the plant chlorinates water in the final steps of treatment. Three tons of chlorine are stored on site in the form of gas liquified by pressure. Chlorine is a water-soluble, poisonous gas that is highly irritating to the respiratory organs. At concentrations of 15 parts per million (ppm), chlorine is immediately irritating to humans by inhalation. At concentrations of 50 ppm, chlorine is dangerous even for brief exposures, and exposures of 1,000 ppm may be fatal even if exposure is brief. Long term damage from chlorine gas exposure includes changes in the trachea, bronchi, emphysema, and congestion in the respiratory system. Short term effects include coughing, vomiting, headache, and chest pains. However, the human olfactory sense can detect chlorine concentrations as low as 3.5 ppm, so extensive exposure rarely occurs. 2.0 RELEASE SCENARIOS In accordance with federal regulation, plant management has modeled for two accidental release scenarios: "worst-case" and "alternative-case." Worst-Case Analysis uses conservative assumptions to determine the greatest distance that a release will travel before it is not longer a hazardous threat. Alternative-Case Analysis demonstrates an off-site impact for a smaller release. Scenarios are described briefly below. A) Worst-Case Scenario for Chlorine Release The worst-case scenario describes a situation in which a one-ton storage container releases all 2,000 pounds of the chlorine gas it contains in ten minutes. Under stable atmospheric conditions with a one and one-half meter per second wind, toxic concentrations of chlorine gas would spread to a radius of 1.3 miles from the release site, affecting a residential population of 1968 people. Accordingly, safet y inspections and safety plans have been completed in the fullest to help prevent such an occurrence. B) Alternative-Case Scenario for Chlorine Release The alternate-case scenario describes a situation in which a one-ton storage container suffers a vessel leak and releases 2,000 pounds of its chlorine gas in 67 minutes. Under slightly unstable atmospheric conditions with a three meter per second wind, toxic concentrations of chlorine would travel to a radius of 0.9 miles from the release site, affecting a residential population of 943 persons. Safety inspections and safety plans are in effect to help ensure against this type of release. Several mechanisms already in place ensure quick response time and release control. These mechanisms include relief valves, manual and automatic shutoffs, alarms and emergency procedures, and emergency air supply. Also, the placement of chlorine containers within an enclosed structure slows spread time, therefore increasing time for emerge ncy response and public notification. Control mechanisms serve to make both release scenarios highly unlikely. 3.0 ACCIDENT HISTORY & ACCIDENTAL RELEASE PREVENTION PROGRAM The Radford Water Treatment Plant can certify that there have been no releases of chlorine in the past five years that have resulted in any off site impact. The plant is proud of its accident-free history and has put into effect an extensive accidental release prevention program to maintain its excellent safety record. As an affected facility under Occupational Health and Safety Act Process Safety Management (OSHA PSM) requirements, the plant is a Program 3 participant. The most extensive of the three RMP programs, Program 3 includes a number of requirements that closely track OSHA PSM requirements. Program 3 also focuses on the off-site consequences of an accidental release. The prevention program outlines information and procedures regarding all aspects of safe operation, including process safety infor mation, Process Hazard Analysis (PHA), operating procedures, mechanical integrity, and personnel training. The PHA is designed to be conducted by a cross-section of facility employees, with guidance from employees directly involved in the chlorination process. The PHA team identifies, evaluates, and implements controls associated with hazards in the chlorination process. The overall purpose of the PHA is to comply with the PSM/RMProgram regulations and to prevent or minimize the effects of a chemical release. The PHA team may conduct a new hazard analysis if significant modifications have been made to the current process or new regulated processes are added. PHAs are, however, updated and revalidated a t least every five years after completion of initial PHAs. The program also ensures that the plant maintains up-to-date, accurate, written Operating Procedures that provide clear instructions for all covered processes. Effective operating procedures, when combined with operato r training, are instrumental in guaranteeing safe operation of the systems and preventing accidental releases. The mechanical integrity program is integral in preventing accidental chemical releases that may result from mechanical failure of improperly maintained equipment. This program outlines equipment maintenance, including maintenance, testing, and inspection schedules and procedures, maintenance personnel training, correction of equipment deficiencies, and quality assurance of new equipment. Finally, personnel training practices ensure that all employees, including maintenance and contract employees, working on or near the chlorination process fully understand the processes and safety measures necessary for correct operation. All personnel currently working at the plant have been certified as having all of the required knowledge, skills, and abilities to conduct their jobs safely and efficiently. In addition, the plant will train and certify new personnel and will conduct mandatory refresher courses for all personnel. 4.0 EMERGENCY RESPONSE PROGRAM The Radford Water Treatment Plant is included in the city of Radford Community Emergency Response Plan, and is therefore not required to develop a facility Emergency Response Plan (ERP). Nontheless, the Radford Water Treatment Plant has voluntarily developed an ERP that includes a) guidance for responding to an emergency in the Safety and Training manual located in the control building and the water treatment plant laboratory, b) coordination with community emergency response organizations, and c) the establishment of a First Response Team. The First Response Team is comprised of operators and maintenance staff from the water and wastewater treatment plants who are trained to safely contain and repair an emergency chlorine leak. The plant conducts awareness-level emergency response training of all personnel on-site. In addition, all personnel who are emergency response team members receive respo nder-level training, depending on their assigned duties and responsibilities in an emergency. Community responder organizations who will assist in major incidents will be provided with a copy of the ERP and subsequent updates. TheRadford Emergency Services Coordinator will arrange for one meeting, drill, or exercise each year with these local organizations to promote preparedness for effective response in the event of an incident. The Radford Emergency Services coordinator will also be responsible for outreach to any institutions (i.e., schools) in the area as needed to implement the plan. 5.0 NOTES Some of the chlorination equipment is in the process of being replaced. The replacement equipment will function the same as the current equipment, and all operations and maintenance manuals, critical equipment lists, etc. that are affected by the change will be updated as appropriate. The replacements will not require a change in the off-site consequence analysis, PHA, or the progr am level.1.0 SOURCE & SUBSTANCE The Radford Water Treatment Plant supplies the City of Radford and areas of Montgomery County with four million gallons of drinking water each day. In order to remove harmful pathogens from water before it is distributed, the plant chlorinates water in the final steps of treatment. Three tons of chlorine are stored on site in the form of gas liquified by pressure. Chlorine is a water-soluble, poisonous gas that is highly irritating to the respiratory organs. At concentrations of 15 parts per million (ppm), chlorine is immediately irritating to humans by inhalation. At concentrations of 50 ppm, chlorine is dangerous even for brief exposures, and exposures of 1,000 ppm may be fatal even if exposure is brief. Long term damage from chlorine gas exposure includes changes in the trachea, bronchi, emphysema, and congestion in the respiratory system. Short term effects include coughing, vomiting, headache, and chest pains. However, the human olfacto ry sense can detect chlorine concentrations as low as 3.5 ppm, so extensive exposure rarely occurs. 2.0 RELEASE SCENARIOS In accordance with federal regulation, plant management has modeled for two accidental release scenarios: "worst-case" and "alternative-case." Worst-Case Analysis uses conservative assumptions to determine the greatest distance that a release will travel before it is not longer a hazardous threat. Alternative-Case Analysis demonstrates an off-site impact for a smaller release. Scenarios are described briefly below. A) Worst-Case Scenario for Chlorine Release The worst-case scenario describes a situation in which a one-ton storage container releases all 2,000 pounds of the chlorine gas it contains in ten minutes. Under stable atmospheric conditions with a one and one-half meter per second wind, toxic concentrations of chlorine gas would spread to a radius of 1.3 miles from the release site, affecting a residential population of 1968 people. According ly, safety inspections and safety plans have been completed in the fullest to help prevent such an occurrence. B) Alternative-Case Scenario for Chlorine Release The alternate-case scenario describes a situation in which a one-ton storage container suffers a vessel leak and releases 2,000 pounds of its chlorine gas in 67 minutes. Under slightly unstable atmospheric conditions with a three meter per second wind, toxic concentrations of chlorine would travel to a radius of 0.9 miles from the release site, affecting a residential population of 943 persons. Safety inspections and safety plans are in effect to help ensure against this type of release. Several mechanisms already in place ensure quick response time and release control. These mechanisms include relief valves, manual and automatic shutoffs, alarms and emergency procedures, and emergency air supply. Also, the placement of chlorine containers within an enclosed structure slows spread time, therefore increasing time f or emergency response and public notification. Control mechanisms serve to make both release scenarios highly unlikely. 3.0 ACCIDENT HISTORY & ACCIDENTAL RELEASE PREVENTION PROGRAM The Radford Water Treatment Plant can certify that there have been no releases of chlorine in the past five years that have resulted in any off site impact. The plant is proud of its accident-free history and has put into effect an extensive accidental release prevention program to maintain its excellent safety record. As an affected facility under Occupational Health and Safety Act Process Safety Management (OSHA PSM) requirements, the plant is a Program 3 participant. The most extensive of the three RMP programs, Program 3 includes a number of requirements that closely track OSHA PSM requirements. Program 3 also focuses on the off-site consequences of an accidental release. The prevention program outlines information and procedures regarding all aspects of safe operation, including process saf ety information, Process Hazard Analysis (PHA), operating procedures, mechanical integrity, and personnel training. The PHA is designed to be conducted by a cross-section of facility employees, with guidance from employees directly involved in the chlorination process. The PHA team identifies, evaluates, and implements controls associated with hazards in the chlorination process. The overall purpose of the PHA is to comply with the PSM/RMProgram regulations and to prevent or minimize the effects of a chemical release. The PHA team may conduct a new hazard analysis if significant modifications have been made to the current process or new regulated processes are added. PHAs are, however, updated and revalidated a t least every five years after completion of initial PHAs. The program also ensures that the plant maintains up-to-date, accurate, written Operating Procedures that provide clear instructions for all covered processes. Effective operating procedures, when combined wit h operator training, are instrumental in guaranteeing safe operation of the systems and preventing accidental releases. The mechanical integrity program is integral in preventing accidental chemical releases that may result from mechanical failure of improperly maintained equipment. This program outlines equipment maintenance, including maintenance, testing, and inspection schedules and procedures, maintenance personnel training, correction of equipment deficiencies, and quality assurance of new equipment. Finally, personnel training practices ensure that all employees, including maintenance and contract employees, working on or near the chlorination process fully understand the processes and safety measures necessary for correct operation. All personnel currently working at the plant have been certified as having all of the required knowledge, skills, and abilities to conduct their jobs safely and efficiently. In addition, the plant will train and certify new personnel and wil l conduct mandatory refresher courses for all personnel. 4.0 EMERGENCY RESPONSE PROGRAM The Radford Water Treatment Plant is included in the city of Radford Community Emergency Response Plan, and is therefore not required to develop a facility Emergency Response Plan (ERP). Nontheless, the Radford Water Treatment Plant has voluntarily developed an ERP that includes a) guidance for responding to an emergency in the Safety and Training manual located in the control building and the water treatment plant laboratory, b) coordination with community emergency response organizations, and c) the establishment of a First Response Team. The First Response Team is comprised of operators and maintenance staff from the water and wastewater treatment plants who are trained to safely contain and repair an emergency chlorine leak. The plant conducts awareness-level emergency response training of all personnel on-site. In addition, all personnel who are emergency response team members rece ive responder-level training, depending on their assigned duties and responsibilities in an emergency. Community responder organizations who will assist in major incidents will be provided with a copy of the ERP and subsequent updates. TheRadford Emergency Services Coordinator will arrange for one meeting, drill, or exercise each year with these local organizations to promote preparedness for effective response in the event of an incident. The Radford Emergency Services coordinator will also be responsible for outreach to any institutions (i.e., schools) in the area as needed to implement the plan. 5.0 NOTES Some of the chlorination equipment is in the process of being replaced. The replacement equipment will function the same as the current equipment, and all operations and maintenance manuals, critical equipment lists, etc. that are affected by the change will be updated as appropriate. The replacements will not require a change in the off-site consequence analysis, PHA, or the program level. |