Jamestown Water Treatment Plant - Executive Summary |
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JAMESTOWN WATER TREATMENT PLANT 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. This building is constructed of prestressed concrete members. This type of construction offers resistance to disaster damage since it is non-combustible and, due to the weight and strength of the components, resistant to natural weather disasters. However, t he presence of doors which are of lighter construction, the building envelope could be violated, thus opening the cylinder room to the atmosphere, i.e., the worst case scenario is not entirely mitigated by the building envelope. B. STATIONARY SOURCE The regulated substances is chlorine which is used in the disinfection process of treated water. The quantity of chlorine on the site and connected 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 chlorin e 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 the North Dakota State Hospital, the North Dakota State Penetentiary, approximately 3,800 residents, and major commercial and industrial sites, including a large mall and motels. 2. Alternate Release Scenario: The alternate release scenario consists of a release of 2,000 pounds of chlorine over a period of thirteen 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 t his distance includes the 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 chlorine at this facility. F. EMERGENCY RESPONSE PROGRAM An emergency response program specifically for this facility developed in the early to mid 1990's and there is an emergency response program developed by the Stutsman County 911/Emergency Management office that cover the hazards that may exist at this facility if a release should occur. In general, the site specific program discusses isolation of the leak (if possible, before additional emergency assistance arrives), contacting emergen cy 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 review and update of the site specific emergency response plan, and increased involvement of employees in safety evaluations and programs. These programs will be developed to focus on employee safety and off-site consequences. |