Michigan City Water Filtration Plant - Executive Summary |
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The Michigan City Department of Water Works (MCDWW) accidental release prevention policy involves a unified approach that integrates technologies, procedures, and management practices. All applicable procedures of the U.S. Environmental Protection Agency (EPA) Prevention Program are adhered to. The MCDWW emergency response policy involves the preparation of a response plan which is tailored to its facility and to the emergency response service available in the community, and is in compliance with the EPA Emergency Response Program requirements. The MCDWW Water Filtration Plant, located at 111 Lake Shore Drive, is a 20 million gallon per day water treatment plant. There are four major structures on the plant site; the Low Lift Building, the North Pumping Building, the Head House and Filtration Building, and the 100,000 gallon Wash Water Tank. The primary activity at the plant is the treatment of Lake Michigan water for distribution to the City of Michigan City and the Towns of Mich iana, Grand Beach, and Trail Creek. The MCDWW uses one regulated substance, chlorine as apre-oxident in the treatment process and as a disinfectant in the distribution system. The chlorination facilities are located in a specially designed room in the recently constructed North Pumping Building. The facilities consists of ton liquid chlorine containers, five vacuum type chlorinators, and various safety equipment. The maximum amount of chlorine on site at any one time is limited to nine chlorine ton containers. The facilities include the following design features for the protection of plant personnel and the public: Chlorine storage and feed facilities are all located in one room which is isolated from the rest of the building. Chlorine cylinders are delivered directly into the Chlorine Room. Cylinders are never stored outside of the Chlorine Room. A sump is provided in the Chlorine Room to minimize liquid surface area to reduce the evaporation rate of the liquid in the event of a significant leak. The heating and ventilation system is design to shut down in the event of a leak thereby containing the chemical in the Chlorine Room. Vacuum regulators are located on the ton containers eliminating the potential of a pressurize pipe failure. The vacuum regulators are designed to shutoff the flow of chlorine should there be leak in the vacuum feed lines. Hazard safety signs are provided on every entry door for emergency/fire personnel. Alarm lights are provided outside each Chlorine Room door. A gas scrubber, designed to contain and neutralize the chlorine gas from a one ton chlorine spill, is located in an adjacent room. A chlorine leak detector is provided outside the room with a sensor inside that can detect chlorine in the air at 1 part per million. In the event of a leak, the detector signals the heating and ventilation system to shut down, the alarm lights outside the entrance doors to flash, the plant alarm to sound, and the gas scrubber to operate. A large standby generator, located in the North Pumping Building, is available to provide emergency power to the plant and the chlorine gas scrubber in the event of a power failure. The water treatment facility is normally manned twenty four hours a day. All of the chemical treatment facilities including the chlorine facilities are automated and can be monitored from a number of operator interface stations strategicaly located throughout the plant. Water Department employees, who are trained to responed in the event of an emergency, visually check the chlorine storage and feed facilities at least twice an hour ever day and ever night. They respond to any trouble alarms which may occur. In the event of a small leak, Water Department personnel have repair equipment and tools, protective gear and self-contained breathing apparatus that can be used if necessary to enter the room and stop the leak. To comply with the requirements of this risk management p lan, the MCDWW has performed Offsite Consequence Analyses for two release scenarios. The "worst-case release scenario" has significant offsite impacts. The "alternative release scenario," one that is defined as "more likely to occur than the worst-case scenario," also has offsite impacts. The worst-case scenario, should it ever occur, could result in impact to individuals in schools, residences, hospitals, commercial, office and industrial and recreational areas depending on the wind speed and direction at the time of the release. The contaiment and treatment systems at the Water Filtration Plant, and the safety training and procedures performed by the MCDWW personnel make it very unlikely that the worst-case scenario would ever happen. The alternative release scenario, should it ever occur, could result in impact to individuals in residences, and recreational areas depending on the wind speed and direction at the time of the release. Again the containment and treatment systems a t the Water Filtration Plant, and the safety training and procedures performed by the MCDWW personnel make it unlikely that even an alternative scenario would ever happen. The MCDWW accidential release prevention program is based on the following key elements: High level of training of Department employees, Preventive maintenance program, Use of state-of-the-art process and saftey equipment, Performance of a hazard review of equipment and procedures, Implimentation of an auditing and inspection program. Chemical-specific prevention steps include availabiltiy of self-contained breathing apparatus (SCBA), awareness of the hazardous and toxic properties of chlorine and the presence of shlorine detectors. No reportable accidental releases of chlorine have occurred at this facility in the past five years. The facility has an emergency release program, which has been coordinated (reviewed) by the Michigan City police and fire departments and the local emergency pl anning committee (LEPC) for Laporte County. This program includes an emergency response decision tree and a notification plan. Emergency response drills and drill evaluations are conducted annually, emergency operation response procedures are also reviewed at that time. |