Nashville Waste Water Treatment Plant - Executive Summary |
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The Nashville Wastewater Treatment Plant facility uses Chlorine, which is considered hazardous by EPA. The same properties that make Chlorine valuable as a water treatment chemical also make it necessary to observe certain safety precautions in handling materials. The prevention of unnecessary human exposure reduces the threat to the health and safety of employees as well as to nearby members of the community. The primary goal of this Risk Management Plan is to ensure the safety of the employees of this facility and all residents that may be impacted by a release from this facility. It is the policy of the City of Nashville to adhere to all applicable federal and state rules and regulations. Safety depends upon the manner in which Chlorine is handled, the safety devices inherent in the design of the facility, and the training of the personnel. This Risk Management Program, including the Emergency Response Program, was developed with the assistance of ALTEC Environmental Consultan ts, Inc. and NRS Consulting Engineers, Inc. The Emergency Response Plan includes procedures for notification of the appropriate agencies and potentially affected members of the community. In addition, it provides procedures for mitigating any releases that may cause harm to the community. The primary purpose of this facility is to treat the wastewater by utilizing a chemical such as Chlorine. Chlorine is received in individual one-ton cylinders and stored until needed. Chlorine is injected into the wastewater treatment system by automatic feeders. The feed system uses a vacuum "shut-off" system which is designed to automatically shut the system down if a leak occurs. Access to the site is restricted to authorized facility employees, authorized management personnel and authorized contractors. The regulated substance handled at this facility is Chlorine. The maximum amount of Chlorine stored at this facility is 2,400 pounds. The worst-case scenario is failure of and total rele ase from the largest storage tank when filled to capacity, resulting in a release of 2,000 pounds of Chlorine. Chlorine creates a hazard when released. Based on the "Back Up Information For The Hazard Assessment in the RMP Offsite Consequence Analysis Guidance" and "Guidance for Wastewater Treatment Facilities," the Chlorine is below the recommended threshold quantity listed in the "Accidental Release Prevention List." We have continued to process this plant at a Program 2 level because of the proximity of residential facilities within the endpoint. Active mitigation has been considered for this scenario. The Chlorine storage tanks are located in the Chlorine Cylinder Room which is constructed of a concrete wall on three sides and one open side. It is assumed that the entire contents are released as a vapor. The distance to the endpoint of 0.0087 mg/l for the worst-case scenario is 1.3 miles. An alternative scenario was determined for this facility. However, the alternative release should be minimal due to the type of control system in place. The vacuum "shut-off" system has been determined to be effective in preventing greater than small quantities of Chlorine from being released. Estimations based on the line capacity for the feeder lines would be approximately 10 pounds released into the atmosphere under this scenario. This quantity of Chlorine vapor release would result in a distance to endpoint of approximately 0.1 of a mile. This wastewater treatment facility complies with EPA's Accidental Release Prevention Rule and with all applicable State of Arkansas codes and regulations. There have been no accidental releases of Chlorine in the last five years. The Emergency Response Program was developed for the City of Nashville and the surrounding areas with the assistance of NRS Consulting Engineers, Inc. This program has been discussed with the Arkansas Office of Emergency Preparedness and the Nashville Fire Department. The Chlorine feed system wa s constructed at this facility in 1999 and meets all design requirements for and complies with all applicable regulations for wastewater treatment facilities. |