Tybee Island Wastewater Treatment Plant - Executive Summary |
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Tybee Island Wastewater Treatment Plant Risk Management Plan Executive Summary The Tybee Island Wastewater Treatment Plant provides wastewater treatment to the City of Tybee Island, Georgia. The plant is permitted for a monthly average flow of 1.0 million gallons per day. The facility uses oxidation ditch activated sludge process to treat the incoming wastewater flow. The treated, clear effluent water is disinfected using chlorine prior to discharge. The plant handles one regulated substance in excess of the Environmental Protection Agency's threshold limit for accidental release prevention. The facility receives and stores chlorine in one ton cylinders. The maximum number of cylinders on site is two. Chlorine gas is greenish yellow in color and liquid chlorine has a clear amber color. Chlorine gas is approximately 2 = times heavier than air and liquid chlorine is approximately 1 = times heavier than water. Chlorine in non-explosive and it's odor is easily detectable at very low concentrations. To help in the prevention of accidental releases of chlorine, the Tybee Island Wastewater Treatment Plant safety program includes maintaining the equipment to insure proper operation by qualified personnel who receive on the job training in chlorine handling safety. The worst case scenario of chlorine release assumes a complete structural failure of a full one ton cylinder over a ten minute period under worst case meteorological conditions. The toxic endpoint distance of the worst case release scenario is 1.3 miles centered at the Tybee Island Wastewater Treatment Plant. Since the facility is located in a populated area, the toxic cloud formed by the chlorine would reach nearby public receptors. The alternate case scenario of chlorine release is based on failure of a 1/4 inch flexible connector between a full chlorine container and the chlorine header. Assuming typical meteorological conditions and a release over a period of 60 minutes, the endpoint distance o f the alternate case release is 0.1 miles centered at the Tybee Island Wastewater Treatment Plant. Since the facility is located in a populated area, the toxic cloud formed by the chlorine would reach nearby public receptors. In the past five years, the Tybee Island Wastewater Treatment Plant has had no accidental releases of chlorine. The Tybee Island Wastewater Treatment Plant emergency response program consists of personnel trained to respond quickly and safely to emergencies. The plant personnel are instructed to notify the Tybee Island Fire Department of any emergencies. |