Wastewater Odor Control Station - Executive Summary |
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JAMESTOWN WASTEWATER ODOR CONTROL STATION JAMESTOWN, NORTH DAKOTA EXECUTIVE SUMMARY A. ACCIDENTAL RELEASE PREVENTION AND EMERGENCY RESPONSE POLICIES The City of Jamestown has developed and implemented policies for safety with respect to the hazardous chemicals on the site. These policies include worker safety and emergency response protocols. Included in the facility is a chlorine scrubber, which, as an active mitigation device, will prevent release of chlorine to the atmosphere, should a release occur. Other active mitigation devices include chlorine leak detectors and a ventilation system that is activated when the cylinder room is occupied. Passive mitigation measures include the building which houses the chlorine cylinders. B. STATIONARY SOURCE The regulated substance handled includes chlorine which is used in the oxidation process of wastewater to reduce the odors related to hydrogen sulfide gas in the wastewater. The quantity of chlorine on the site and connecte d to metering devices are subject to OSHA Process Safety Management Standard since the quantity exceeds the threshold quantity in 29 CFR 1910.119. However, worksite safety in North Dakota falls under the jurisdiction of the North Dakota Workers Compensation Bureau, not OSHA. Because the quantity of chlorine exceeds the threshold established by OSHA, the chlorine process is a Program Level 3 process. C. OFFSITE CONSEQUENCE ANALYSIS 1. Worst Case Release Scenario: The worst case scenario consists of a release of 2,000 pounds of chlorine over a period of ten minutes. Since the chlorine is stored indoors, passive mitigation is provided by the building itself. The storage of chlorine outdoors is an administrative control which reduces the end point distances. The endpoint distance is 0.9 miles based on urban topography. The area within this distance includes approximately 5,700 residents and several commercial and industrial sites. 2. Alternate Release Scenario: The alt ernate release scenario consists of a release of 4,000 pounds of chlorine over a period of twenty-six minutes. Although the passive mitigation provided by the building enclosure is taken into consideration, the active mitigation provided by the scrubber is neglected. If the mitigation provided by the scrubber was taken into account, there would be no offsite consequences for the chlorine leak. The end point distance for this scenario is 0.2 miles based on urban topography. The area within this distance includes approximately 500 residents. D. GENERAL ACCIDENTAL RELEASE PREVENTION POLICY The general accidental release prevention policy includes training for employees, restrictions on hot work in the storage/feeder room. Inspection and testing of detectors, alarm systems and scrubbers is also performed on a regular basis to verify that measures are operable and available should the need arise. E. FIVE-YEAR ACCIDENT HISTORY There have been no accidents with respect to the chl orine at this facility. F. EMERGENCY RESPONSE PROGRAM Whereas an emergency response program specifically for this facility has not been developed, the programs developed by the Stutsman County 911/Emergency Management office and programs developed for the water treatment plant cover the hazards that may exist at this facility if a release should occur. In general, the program discusses isolation of the leak (if possible, before additional emergency assistance arrives), contacting emergency responders including the fire department and law enforcement officials and maintaining operation of the chlorine scrubber, if required. G. PLANNED CHANGES TO IMPROVE SAFETY The facility has had no incidents which would indicate that safety programs for workers are inadequate and in need of change. Planned changes for safety programs include the development of a site specific emergency response plan, and increased involvement of employees in safety evaluations and programs. These programs wil l be developed to focus on employee safety and off-site consequences. |