Lucas Wastewater Treatment Plant - Executive Summary |
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The North Regional WWTP utilizes chlorine gas as a disinfectant and sulfur dioxide as a dechlorinant prior to discharging plant effluent to the Red River. To date, no major accidental releases of either chemical have occurred. The worst case release scenario for chlorine gas suggests that a radius of 3 miles around the facility could be affected should a one-ton chlorine cylinder rupture. Persons within this zone could potentially be exposed to a 3 ppm concentration of chlorine ggas, assuming wind speed was 1.5 meters per second and the stability of the atmosphere was classified as "F". From U.S. censuse data, the population per square mile in Shreveport, LA is approximately 194.3 persons per square mile, indicating that approximately 5,500 persons could potentially be affected during the worst case release scenario of chlorine gas. A few schools and hospitals are located within this radius of concern. The alternative release scenario for chlorine gas and for sulfur dioxide tha t could be more likely to occur would involve a tubing filure, bad connection, or valve failure resulting in the release of chlorine gas through a 5/16-inch diameter valve body opening. This scenario could potentially affect a radius of 0.56 miles or almost 22 persons (on-site employees). The circle of concern does not include any schools or hospitals or other public receptors outside of residential dwellings. Current safety, training, operation, and maintenance practices at the North Regional Wastewater Treatment Plant follow the guidelines set forth in the Risk Management Proigram. Deficiencies noted during the hazard review are presently being addressed. Procedures documenting compliance with the legislation provided in 40 CFR 68.48 through 60 are provided in a series of three-ring binders located in the Chief Supervisor/Operations' office at the North Regional WWTP. The Chief Superviosr/Operations will be responsible for performing the compliance audit every three years and updating the documentation as required. |