City of Dyersburg Wastewater Plant - Executive Summary |
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CITY OF DYERSBURG WASTEWATER PLANT 1. The City of Dyersburg Wastewater Plant's accidental release prevention includes training, written instructions, checking the process frequently, and preventive maintenance on equipment. Written emergency response actions include notification of the local Fire Department, the chemical supplier, and the chemical emergency hotline. Also employees receive training on how to stop a chorine and sulfur dioxide leak. 2. The Wastewater Plant treats sewage and industrial wastewater to prevent pollution of the receiving stream. Chlorine is injected into the water after the treatment process to destroy pathogenic organisms. After the chlorination process, sulfur dioxide is added to reduce the chlorine to a nontoxic level for aquatic life. Up to four ton containers of chlorine and up to three ton containers of sulfur dioxide are stored on site. 3. The worst case scenario is defined by EPA as the release of the largest quantity of a regulated substanc e from a vessel or process line failure that results in the greatest distance to a specified endpoint. This endpoint for chlorine is 0.0087 mg/l. The requirement is to assume that the maximum quantity in the largest vessel is released as a gas in ten minutes. Assumptions are made regarding atmospheric stability, wind speed, and other factors and using the Offsite Consequence Analysis in Risk Management Program Guidance for Wastewater Treatment Plants,Exhibit 4-4 and 4-6, a distance of 0.9 miles is the distance to the toxic endpoint. The alternative scenario is one that is more likely to occur. A valve leak was selected as most likely to occur. Using Exhibit 4-15 and 4-19, a distance of 0.1 miles is obtained for the toxic endpoint for chlorine and sulfur dioxide in the alternative scenario. 4. The general accidental release prevention program is based on the following key elements: Operator training Preventive maintenance program Safety equipment Operating proc edures written with participation of the operators Auditing and inspections programs The chemical specific prevention steps include: availablity of self contained breathing apparatus (SCBA), operators awareness of the hazardous and toxic properties of chlorine and sulfur dioxide, and the presence of chlorine and sulfur dioxide alarms. 5. No accidental releases of chlorine have occurred at this facility in the past five years. 6. The Emergency Response Program involves coordination with the local Fire Department and City of Dyersburg Emergency Disaster Plan. 7. The City of Dyersburg and the Wastewater Plant are continually seeking ways to improve the safety for it's employees and the public. Employees are encouraged to work safely and to report hazardous conditions. |