E.A Fairbarn Water Treatment Plant - Executive Summary |
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The City of Sacramento Department of Utilities recognizes a responsibility to safely operate its facilities in order to protect the surrounding community, employees, and the environment. The Department has taken a proactive stance to promote the overall safe operation of its chlorine storage, handling, and use, with programs to prevent accidents from occurring, planning for emergencies, and maintaining the equipment needed if an emergency does occur. The RMP formalizes and improves existing programs and procedures so that these programs may be reviewed more efficiently. The E.A. Fairbarn Water Treatment Plant contains 16 chlorine tank containers that are used in the disinfection process. Consequence modeling was conducted to determine the release distances from the site. The worst-case release scenarios represent a release of the largest vessel's contents when full over a 10-minute release period. The alternative scenario consists of a release of chlorine through a break in the container flexible connector (also known as a pigtail). This failure of the pigtail could be caused corrosion (known as chloride stress cracking) or through mechanical damage. This postulated failure would result in a chlorine vapor release from the broken connection. It was assumed that the container was full and that the release rate was constant (chlorine temperature remaining at the ambient temperature). This is a conservative assumption. In a real release scenario, the temperature of the chlorine would drop rapidly from the chilling effect that occurs when a compressed, liquified gas is depressurized. This would cause the release rate to diminish over time. Release time was conservatively estimated to occur over ten minutes. The Department of Utilities has assigned personnel responsibility for implementing elements of CalARP/RMP. The Water & Sewer Superintendent is ultimately responsible for implementation of the CalARP/RMP Program, auditing for compliance, and implement ing the PSM Program elements. Implementation of the program is done in a continuous effort to improve safety at all Department facilities. There have been many recent examples of improvements to the chlorine handling system. They include: 7 Completion of recommendations related to a seismic evaluation of the Sacramento River Wastewater Treatment Plant 7 Consideration of continuous telemetry from well sites to measure if a release has occurred. Construction of this monitoring system is scheduled to begin in Spring 1999. 7 Consideration of less hazardous disinfectants such as calcium hypochlorite at the well sites instead of chlorine. There is an ongoing pilot project utilizing a calcium hypochlorite tablet feeder. 7 Completion of recommendations from the PHA revalidation of all chlorine handling systems. The Department strives to implement the prevention program in a timely manner and anticipates that all elements would be completed by July 1999. |