Cunningham-East Montgomery Water Treatment Plant - Executive Summary |
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7 The Cunningham-East Montgomery Water Treatment Plant (CEMWTP) Risk Management Plan consist of the Cunningham-East Montgomery W.T.P. employees working together to insure that all applicable procedures of the U.S. Environmental Protection Agency (EPA) Prevention Program are adhered to. 7 CEMWTP uses chlorine to disinfect the water treated at this facility. CEMWTP has a chlorine storage room on the southwest corner of the building. This room houses the chlorine storage equipment, leak detection equipment and the manifold that the chlorine cylinders are mounted to. The amount of chlorine handled is four, one ton containers. The chlorine storage room is usually checked each shift. In addition to the storage room on the first floor, there is chlorine feed room on the second floor. The room on the second floor consists of chlorine feed equipment as well as chlorine leak detection equipment. CEMWTP operators Respond to any trouble alarms that may occur. 7 The offsite con sequence analysis includes consideration of two chlorine release scenarios, identified as "worst case release" and "alternative scenario". The first scenario is defined by EPA, which states that "the owner or operator shall assume that the maximum quantity in the largest vessel is released as a gas over 10 minutes," due to an unspecified failure. The alternative scenario is defined as "more likely to occur than the worst-case release scenario". 7 The worst-case release scenario at Cunningham-East Montgomery W.T.P. involves failure of a one ton container. The model used for this scenario is RMP*Comp Ver.1.05 with the results as follows Chemical: Chlorine, CAS#: 7782-50-5 Category: Toxic Gas Scenario: Worst-case Liquefied under pressure Quantity Released: 1 ton Release Duration: 10 Min. Release Rate: 110 pounds per min. Mitigation Measures: Released in enclosed space, in direct contact with outside air. Topography: Rural surroundings (terrain generally flat and unobstructed) T oxic Endpoint: 0.0087 mg/l; basis: EPRG-2 Estimated Distance to Toxic Endpoint: 2.2 miles Number of People Affected: 100 Assumptions About This Scenario Wind Speed: 1.5 Meters/second (3.4 miles/hour) Stability Class: F Air Temperature: 77 degrees F (25 degrees C) 7 The alternative release scenario involves a = inch hole 15 inches below the top level of the liquid in a 1 ton cylinder. Again the model used was RMP*Comp Ver.1.05 with the results as follows Chemical: Chlorine, CAS#: 7782-50-5 Category: Toxic Gas Scenario: Alternative Liquefied under pressure Release Duration: 8 Min. Storage Parameters: Hole in liquid space of tank Height of Liquid Column Above Hole: 15 inches Release Rate: 1580 pounds per minute Mitigation Measures: Released in enclosed space, in direct contact with outside air. Topography: Rural surroundings (terrain generally flat and unobstructed) Toxic Endpoint: 0.0087 mg/l; basis: EPRG-2 Estimated Distance to Toxic Endpoint: 1.2 miles Number of People Affected: 50 Assumptions About This Scenario Wind Speed: 3 Meters/second (6.7miles/hour) Stability Class: D Air Temperature: 77 degrees F (25 degrees C) 7 The CEMWTP accidental release program is based on the following key elements: (1) Performance of a hazard review of equipment and procedures (2) High level of training of the operators (3) Preventive maintenance program (4) Use of accurate and effective operating procedures, written with the participation of other employees (5) Weekly inspections of leak detection equipment (6) An ongoing inspection and auditing program 7 There has been no accidental release of chlorine in the past five years at CEMWTP. 7 The emergency response plan at this facility includes coordination with the Montgomery County Government Emergency Management Agency as well as the U.S. Coast Guard. The emergency response plan includes emergency shutdown procedure, evacuation plan, and emergency personnel notification. CEMWTP safety coordinator and plant manage r each review this process annually. |