DELCORA-Western Regional Treatment Plant - Executive Summary |
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DELCORA handles 24 one-ton containers of liquid chlorine. As a result, accidental release prevention and emergency response policies have been instituted which include: operating and maintenance procedures, training and incident investigation programs for handling chlorine; notification of key plant personnel during an emergency; immediately available SCBA and protective equipment to be used by trained personnel; an on-site emergency response plan and procedures for notification of local emergency planning individuals in the event local emergency response is needed. The worst-case scenario as described in this program is the release of the entire contents of a 1-ton liquid chlorine container in ten minutes, or 200 lb./min. All the on-site chlorine containers are enclosed in a building, therefore, the release rate has been reduced to 110 lb./min. for the worst case scenario, a wind speed of 1.5 meters/sec. and atmospheric stability class F was used. Using a combination of local da ta and an approved modeling program, the distance to the Toxic Endpoint Limit (TEL) for a worst case release was determined. This distance, assuming the containers are enclosed in a building, is 2.04 miles. The Alternative Release Scenario as described in this Program was based on a chlorine container isolation valve stem failure. A release rate of 0.16 lb/min., a windspeed of 4.6 meters/sec. and atmospheric stability Class D was used. This data, when modeled, produced no off-site impacts. The dispersion modeling for both scenarios was conducted using the SLABVIEW Program, Version 1.5 and site specific information. The chlorine-specific accidental release prevention program in place at the facility provides written procedures that incorporate operational and maintenance data and training procedures for dependable use of relief valves, leak detection systems, automatic shut-off systems and alarms. Mitigation systems in use include complete enclosure of the chlorine supply and c hlorination system, an automatic container shut-off device and a chlorine scrubber system. No accidents have occurred in the last five years. Procedures are in place to identify and record any future accidents or incidents. An On-Site Emergency Response Program, including an evacuation plan, assembly areas and other safety information has been developed. This Program has been coordinated with the SARA III Off-Site Response Plan, which has been included with the Program and will supersede the on-site response program in the event that an accidental release extends beyond the facility's boundaries. The Authority will update the program as required and will review the program every five years or when applicable on-site conditions change. |