B.E. Payne Water Treatment Plant - Executive Summary |
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(a) The accidental release prevention and emergency response policies at the stationary source. Louisville Water Company continues to be committed to preventing accidental releases of chlorine or any other hazardous chemical. Since the rule requiring this plan is specifically directed toward the prevention of chlorine releases, the discussion will be confined to that chemical. Extremely conservative engineering practices have been observed in the design and operation of the company's chorine feed system such that the probability of accidental release is minimal. Examples of these practices include the building of chlorine storage container containment building, switching from liquid chlorine to gas chlorine feed systems, and the installation of four chlorine detection units which can detect chlorine concentrations as low as one part per million chlorine gas. These devices are located inside the chlorine containment buildings in the immediate vicinity of the chlorine storage contai ners. Two of these detectors control the automatic operation of a chlorine scrubber system. The other two sensors provide continuous remote indication of chlorine concentration inside the containment building to the master water treatment control room, which is continuously manned. The chorine containment building's ventilation and heating systems are interlocked to the chlorine detection system such that both systems automatically stop upon chlorine leak detection. Most notably, LWC operates a state-of-the-art chlorine vacuum feed system, which ensures that any chlorine outside of the containment building is inside piping under vacuum until the chlorine is introduced into the water. Chlorine piping downstream of the vacuum regulators operate under a vacuum and will not leak unless a break in the chlorine vacuum piping and failure of the vacuum regulator occur simultaneously, which would be highly unlikely. In the event of a chlorine leak on the pressurized side of the chlorine f eed system, there is evacuation piping inside the containment building which will provide suction path to a scrubbing system which will remove chlorine from the air prior to air's reintroduction to the environment. Power to the chlorine vacuum feed system is supplied from two independent electric substations. All modifications made to the chlorine containment buildings fully meet all code requirements of the Department of Housing, Buildings, and Construction Division of Fire Prevention for the State of Kentucky. In the event of a chlorine leak, operations personnel have quick access to NIOSH approved half-mask filters so that quick and safe egress and initial investigation may be conducted. Self-contained breathing apparatus is readily available for more thorough investigation and isolation in a contaminated atmosphere. In any capital improvement project within the production or distribution system, exhaustive effort is performed to ensure the identification of a safety-related i tem. Once identified, the resolution of the safety issue is written into contract. The emergency response plan, developed in 1992, is fully integrated into operations at both water treatment plants. The plan was developed in conjunction with public emergency response authorities, in compliance with local, state, and federal laws, and has been tested to respond effectively in the unlikely event of a chemical leak. LWC personnel are trained to initially respond to leak events, train annually to install chlorine "B" and "C" containment kits, plus conduct an annual drill with the Louisville Fire Department Hazards Response Unit to simulate response to a chemical leak. (b) The stationary source and regulated substances handled. The B.E. Payne Water Treatment Plant (BEPWTP) is located at 7400 Upper River Road, Louisville, Kentucky 40059. The chemical that is regulated by the Clean Air Act at the facility is chlorine. (c) The worst-case release scenarios and alternative release scenar ios including administrative controls and mitigation measures to limit the distances for each reported scenario. The worst case scenario for BEPWTP involves the catastrophic release of one ton of chlorine due to the failure of an off-line, full, one-ton chlorine container. The chlorine containment building limits the release rate of the 2000 pounds of chlorine released to the atmosphere to 110 pounds per minute. RMP Comp was used to calculate the distance to endpoint of 0.9 miles. This leak would effect approximately 23,000 persons in the area of this distance. This would include residences and schools in this area. The alternative case scenario for BEPWTP is described below including the necessary calculations. RMP Comp was used with the stated release rate to calculate the distance to toxic endpoint. Guillotine break of a 1" gas chlorine header attached to 6 one-ton cylinders causes a chlorine gas leak. Chlorine cylinders are housed in a 52,000 cubic foot containment buildin g. Chlorine leak detectors rapidly detect the leak and activate chlorine scrubber system. The chlorine scrubber is rated for 5,000 scfm and a maximum outlet concentration of 15 PPM. The chlorine leak is stopped after 60 minutes. The following assumptions were made: 1. Temperature of containment room and ton cylinders remains constant at 770 F. Temperature of both would actually rapidly decrease and reduce chlorine leak rates. 2. Model as 6 times the leak rate from a single ton cylinder. Leak rate from a ton cylinder will be limited by 5/16" valve body opening on the cylinder gas valve. 3. Release Rate QR (in lbs./min): QR = (APSGF)/(square root of TS) QR = release rate of gas from the hole (lb./min) A = area of hole (sq. in) PS = storage pressure (psia) GF = Gas factor TS = storage temperature of gas (K) GF chlorine = 29 PS = vp chlorine @ 770 F = 113 psia TS = 25 + 273.2 = 298.2 K A = 0.0767 sqaure inches QR = (0.0767 X 113 X 29) /( Square root 298.2) QR = 14.55 lbs./min 4. Lea k Rate = 6 X 12.559 lbs./min = 87.3 lbs./min 5. Scrubber Rating = 5000 scfm 6. Release concentration = 15 PPM = 0.0435 mg/l 7. Release rate = 0.0435 mg/l X 28.32 l/ft3 X 5000 ft3/min X 1 lb./ 453,600 mg = 0.0136 lbs./min 8. Total Release = 0.0136 lbs./min X 60 minutes = 0.816 lbs. The distance to the toxic endpoint is less than 0.1 mile. Therefore, the material would not effect the population outside the perimeter of the B.E. Payne Water Treatment Plan grounds. (d) The general accident prevention program and chemical-specific prevention steps. LWC has installed numerous administrative controls and mitigation measures to reduce the probability of an accidental release of chlorine. The most significant is the containment building, which acts as a passive mitigation devices. This building completely encloses the chlorine storage containers at the water treatment plant. Active mitigation devices include chlorine scrubbers installed to remove chlorine from the air inside the contai nment buildings, chlorine leak detectors which control the automatic flow shut-off valves, scrubbing system and doors to the containment buildings. Administrative controls include adherence to Process Safety Management; for example, standard operating procedures are utilized throughout the water treatment facility. Strict adherence to the Process Safety Management Program aids in the prevention of incidents. The Louisville Water Company Process Safety Management Handbook was recently reviewed and updated to reflect changes in safety processes. The revision was completed in March 1999. The Handbook includes general process safety management, process hazards analysis, management of change procedures, operating procedures, safe work practices, training guidelines, mechanical integrity procedures (including maintenance checklists and daily equipment checks), pre-startup review procedures, emergency response procedures, incident investigation guidelines, and audit guidelines for the pr ogram. (e) The five year accident history: According to Federal Register/Volume 61, No. 120, Section 68.42, "the owner or operator shall include in the five-year accident history all accidental releases from covered processes (chlorine) that resulted in deaths, injuries, or significant property damage on site, or know offsite deaths, injuries, evacuations, sheltering in place, property damage, or environmental damage". There have been no instances that would satisfy the above criteria within the previous five years of operation of the Louisville Water Company. (f) The emergency response plan: LWC has individual emergency response plans for each of the water treatment plants regulated by the Clean Air Act. The plan for BEPWTP was placed in effect on June 10, 1992. The plans specifically detail the Louisville Water Company's emergency response plan in compliance with S.A.R.A. Title III Emergency Response and Community Right to Know Act of 1986. The plans were coordinated with t he Kentucky Emergency Response Commission and the Louisville-Jefferson County, Kentucky Local Emergency Planning Committee. The general plan includes: 1. Steps for the prevention of hazardous material spills - includes ongoing surveys of hazardous material storage and handling and employee training. 2. Preparation for a spill - includes organization charts for handling the spill and site specific training for containment of the spill 3. Spill Control Plan - includes the steps in notifying personnel involved and the community. (g) Planned changes to improve safety: As a Total Quality Organization, LWC actively encourages improvement to all processes. All employees are trained to recognize when and how processes can be improved. Operating under the guidelines of Process Safety Management with the management of change element provides a mechanism for constant internal review and improvement in production quality and safety. Plus, Process Safety Management requires five-year revi ews on all aspects of the program. Any avenue for improvement in safety missed over the course of the previous five years would be identified during the exhaustive review conducted every five years. |