James W. Jardine Water Purification Plant (JWPP) - Executive Summary |
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CHLORINE RISK MANAGEMENT PROGRAM (RMP) CITY OF CHICAGO DEPARTMENT OF WATER James W. Jardine Water Purification Plant (JWPP) June 9, 1999 EXECUTIVE SUMMARY Introduction The James W. Jardine Water Purification Plant (JWPP) treats water to potable drinking standards for the City of Chicago and many surrounding communities. The plant uses chlorine to disinfect water from Lake Michigan. The plant stores more than the threshold quantity of 2,500 lbs of chlorine onsite. The disinfection process is the only process at the Jardine facility subject to United States Environmental Protection Agency (USEPA) Risk Management Program (RMP) regulations codified in 40CFR Part 68. Chlorine is an easily liquefiable greenish-yellow gas with a pungent, irritating odor. It is listed by the USEPA as a regulated toxic substance for release prevention. Chlorine is safe to use as a drinking water disinfectant under regular plant conditions when handled with appropriate care. JWPP Chlorine Process Liquid ch lorine is trucked to the plant site in 1-ton (2,000 lbs) pressurized containers by an outside vendor. The containers are unloaded and stored in an enclosed area prior to use. Liquefied chlorine in the individual containers is changed to gas-phase chlorine with evaporators. Chlorine gas is mixed with water at individual application points for disinfection as part of the water treatment process. JWPP Release Prevention and Emergency Response Policy The City of Chicago Department of Water (DOW) in concert with JWPP management is committed to manage and operate the plant in accordance with relevant USEPA regulations and general good operating practices to ensure minimum risk of a chlorine release from the disinfection process. The DOW has voluntarily implemented an Occupational Safety and Health Administration (OSHA) Process Safety Management (PSM) program for the JWPP chlorine process although it is not explicitly subject to this federal program. In order to ensure periodic monitoring and continual evaluation of the RMP/PSM program elements being implemented at the plant, the DOW has instituted an emergency response (ER) organizational structure within the Department and JWPP. In addition to their regular duties, members of this structure have additional RMP/PSM-related responsibilities for the long-term management of the RMP/PSM program. Worst-case Release Scenario As required by USEPA regulations, the worst-case release scenario was assumed to be the complete loss of contents of a 1-ton chlorine container during unloading operations that are performed in an enclosed structure adjoining the filtration building. In this analysis no passive mitigation measures were assumed. The USEPA guidance for defining a worst-case release scenario for unmitigated release of gas is to estimate the release rate over a 10-minute period of the largest quantity resulting from a pipe or vessel failure. Thus, the chlorine emission rate from the worst-case release scenario used was t he loss of 2,000 lbs of chlorine averaged over a 10-minute period, i.e., 200 lbs/min. USEPA's public-domain RMP*Comp model was used to determine the distance to the toxic endpoint of 0.0087 mg/lit (or 3 ppm). The toxic endpoint distance does go offsite. It should be noted that the potential offsite impact due to a release is greatly minimized on account of the location of JWPP which is bounded by Lake Michigan on the north and east. Since almost 75 percent of the area within the circle of influence defined by the distance to the toxic endpoint as the radius is over Lake Michigan, potential offsite impacts are greatly reduced. JWPP employees thoroughly inspect every chlorine container for potential leaks and overall structural integrity upon delivery and prior to process hookup. Chlorine sensors and a system of emergency alarms at strategic locations around the chlorine process initiate the emergency response procedures (i.e., release abatement and evacuation) that includes activatio n of the emergency caustic scrubbers to neutralize potential chlorine releases. This minimizes the chance that a container will fully discharge its contents in a release and minimizes the potential for an offsite impact. Alternative Release Scenario The following three most likely alternative scenarios (ranked in order of probability of occurrence) were identified: - Case (1): Container valve failure; - Case (2): Shear of pigtail containing liquid chlorine; and - Case (3): Over-pressurization of rupture disk The above alternative releases were modeled using USEPA's public-domain RMP*Comp model to determine the maximum distance to the toxic endpoint of 0.0087 mg/lit (or 3 ppm). Effects of both passive mitigation (due to the building enclosure) and active mitigation afforded by the JWPP emergency caustic scrubber system were included in the analysis. The maximum toxic endpoint distance does go offsite, but only by a few hundred feet. It should be noted that any potential offsite impact due to a release is greatly minimized due to JWPP's location, which is bounded by Lake Michigan on the north and east. As noted above, JWPP employees thoroughly inspect every connection from the chlorine container to the liquid piping for potential leaks and overall structural integrity prior to hookup. In addition, JWPP has regular operation and maintenance procedures for evaluating and replacing, if required, container valves and rupture disks. Also, the plant has chlorine sensors and a system of emergency alarms at strategic locations around the chlorine process that initiate the emergency response procedures (i.e., release abatement and evacuation) that include activation of the emergency caustic scrubbers to neutralize potential chlorine releases. This minimizes the chance for a discharge of quantities of chlorine which could result in an offsite impact. Release Prevention Program As a municipal organization JWPP is not subject to OSHA regulations. However, JWPP has proactive ly implemented an OSHA Process Safety Management (PSM) program (codified in 29CFR Part 1910.119) for the chlorine process. The scope of the PSM program encompasses various facets of release prevention; e.g., it engenders employee participation, increases employee awareness about the hazards of handling chlorine, establishes safe standard operating procedures and enhances access to process safety information. In December 1998, JWPP performed a PSM audit and a HAZOP process hazards analysis (PHA) on the chlorine system with the help of outside consultants in order to review existing operating procedures, equipment maintenance schedules, operational safeguards and identify action items to render the process safer. Following the PHA, JWPP developed a written PSM program along with an updated O&M (Operations and Maintenance) Manual with the help of outside consultants. The written PSM program provides the procedural backbone for safe operability functions (i.e., continual review of safe operating procedures, review of mechanical integrity of equipment, improved maintenance schedules, increased training, better access to process safety information and hazard awareness for both employees and onsite contractors, and effective emergency response planning), and allows JWPP to maintain, review and evaluate the program on a periodic basis. The DOW is completing a major upgrade of the JWPP chlorine system equipment piping and safety system. New redundant equipment and piping have been installed to allow frequent inspections and maintenance of the system. The entire chlorine process area, including storage and unloading areas have been enclosed to contain leaks. A new automated chlorine scrubber system has been installed to neutralize potential leaks. These system upgrades complement the organizational and procedural aspects of the prevention program and minimize the risk of release of chlorine from the JWPP process. Five-year Accident History JWPP has been operational si nce 1966. Since that date there have been no serious onsite injuries, no offsite injuries and no offsite environmental damage due to a chlorine release. JWPP had an accidental release of approximately 10 pounds of chlorine gas on September 27, 1995 from a storage vessel. The Local Emergency Planning Committee (i.e., the Chicago Fire Department or CFD) was notified immediately by plant authorities and they responded quickly by dispatching a HAZMAT team and paramedics to the plant. There were no offsite environmental impacts or injuries. As a result of the accidental release, JWPP instituted additional training and new mitigation systems. Since evacuation procedures were initiated and completed successfully, no changes to evacuation procedures were implemented in response to the accidental release. JWPP had another accidental release of approximately 500 pounds of chlorine gas on July 20, 1998 from the failure of rupture disks in the piping system. The emergency caustic scrubber syste m was activated and it helped mitigate the release of chlorine to the atmosphere. The LEPC (i.e., the Chicago Fire Department or CFD) was notified immediately by plant staff and they responded quickly by dispatching a HAZMAT team and paramedics to the plant. As a precaution, people at nearby beaches were evacuated or sheltered-in-place by the Chicago Police Department. There were no offsite injuries or environmental damage from the release. Due to the accidental release, JWPP instituted a number of changes ranging from revised maintenance, revised training, revised operating procedures, new process controls, new mitigation systems and revised emergency response plan. This scenario was analyzed as part of the alternative release scenario offsite consequence analysis. During this analysis, it was determined that the newly installed safety system will direct a leak to the scrubber system minimizing the risk of offsite impacts. Emergency Response Program Since JWPP has adopted the OSHA P SM program, the plant has updated existing procedures for Emergency Planning and Response to conform to applicable PSM regulations. JWPP has adapted the PSM Emergency Response Plan so that also satisfies RMP Part 68 requirements. JWPP has a well delineated emergency response (ER) organization under the command of the emergency response coordinator (ERC) with a set of clearly defined responsibilities and procedures for ER team members. ER team members are regularly evaluated, receive updated training and conduct practice emergency response drills. Besides onsite training and practice, ER team members are responsible for coordinating emergency response activities (e.g., agency notifications) with local emergency responders such as the Chicago Fire Department, Illinois Emergency Management Agency (IEMA) and the National Response Center (NRC) through established channels of communication. The Emergency Response Plan contains detailed notification procedures to be followed by ER team me mbers. JWPP has detailed onsite evacuation procedures customized for the plant in the event of a release of chlorine. JWPP is equipped with appropriate emergency response equipment in readiness for immediate application. The Local Emergency Planning Committee (i.e., the Chicago Fire Department) is responsible for addressing all offsite emergency activities. The City of Chicago Department of Water (DOW) and JWPP management are committed to supporting the emergency response (ER) organization and its prescribed functions. ER team members are drawn from the existing employee pool and the organizational concept fosters pride and emphasizes concerns for safe operation of the plant. The well defined ER organization at JWPP operating in conjunction with the Chicago Fire Department alleviate safety concerns about handling chlorine at the plant. Changes to Improve Safety As discussed above, the DOW is currently completing a major upgrade of the chlorine system equipment piping and safety sys tem. Also modifications to the plantwide communication systems are underway and will be completed by the end of 2001. New redundant equipment and piping have been installed to allow frequent inspections and maintenance of the system. The entire chlorine process area, including storage and unloading areas have been enclosed to contain chlorine leaks. New automated chlorine scrubber systems have been installed to neutralize potential chlorine leaks. Thus, in addition to new and improved training and organizational changes, upgrades to the chlorine system demonstrate the commitment to safety that the DOW has made to both plant employees and the surrounding community. xxOxx |