Southern Union Gas Company - Executive Summary |
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Southern Union Gas Company owns and operates an Ethyl Mercaptan above ground storage tank ("AST") located on a 10 acre parcel of land, one-half mile North of 107 on Highway 493 in La Blanca, near Edinburg, Texas. The process that requires this AST is the odorization of various natural gas pipelines within the area. Natural gas pipelines are regulated by the Texas Railroad Commission and the Department of Transportation. Ethyl Mercaptan is considered to be a hazardous material by the EPA. Southern Union Gas Company is committed to the safety of the public and our employees and complies with applicable federal, state and local regulations. If an emergency situation should ocur at this facility, our dispatch office would be notified immediately through our 1-800-959-LEAK number. It is our policy to also notify the Edinburg Fire Department for this facility, as soon as possible after an emergency has been reported. The Ethyl Mercaptan is stored in a 7,173 gallons AST and associated valves. The AST is filled with approximately 4,000 gallons of Ethyl Mercaptan once each year. The maximum volume of the AST if filled to capacity (assumed to be 88% at 60 F) would be 42,600 pounds. However, the AST has no more than 1,000 gallons of Ethyl Mercaptan when it is filled; therefore, the maximum amount of storage in the AST would not exceed 33,532 pounds. For purposes of the Risk Management Plan, the EPA is requiring a discussion of a worst case scenario (unlikely to occur). The worst case scenario would be the total failure of the AST, resulting in the loss of the entire contents of the AST. Based on the maximum capacity in the tank of 42,600 pounds, the worst case scenario would have an affect beyond the property boundary. The alternate release scenario would also have an affect beyond the property boundary. Please note that because of the odorous nature of Ethyl Mercaptan, extra care is used in handling and transport of this material. Southern Union Gas Company h as never had an accident at this facility involving Ethyl Mercaptan. A Tier Two report is filed every March 1st to the State of Texas Health Department and the local fire department. In the unlikely event of a release of Ethyl Mercaptan at this facility, the Edinburg Fire Department would be called on to provide emergency assistance. |