Joint Regional Plant - Executive Summary |
ACCIDENTAL RELEASE PREVENTION AND EMERGENCY RESPONSE POLICIES Aliso Water Management Agency/South East Regional Reclamation Authority (AWMA/SERRA) has an emergency response plan in effect. The Emergency Response Plan (Plan) is detailed in the Emergency Planning and Response section of this PSM/RMP document. This Plan was designed to meet the following objectives: 1.) To save lives. 2.) To minimize and avoid injuries. 3.) To protect the environment. 4.) To minimize property damage. AWMA/SERRA maintains a safety committee whose members are the designated emergency coordinators for the facility. The Plan provides the response organization and notification procedures, evacuation routes, chlorine health hazards, and mitigation procedures which will be implemented to respond effectively to emergency situations that may arise at the facility. This Plan is reviewed and updated at least once per year. This Plan was reviewed and updated to ensure compliance with the PSM, RMP, and CalARP regulations, and to ensure that the plan is kept current. STATIONARY SOURCE AND REGULATED SUBSTANCE The Joint Regional Plant of Aliso Water Management Agency (AWMA) is located at 29201 La Paz Road in Laguna Niguel. The facility is situated west of the La Paz Road near Kings Road and approximately 2.75 kilometers (1.71miles) west of Interstate 5. The immediate area is primarily residential areas. The chlorine system at the Joint Regional Plant is used for the treatment of wastewater. The Joint Regional Plant uses chlorine for odor control, filamentous control, or disinfection at different processes in the wastewater treatment: 1) influent, 2) return activated sludge (RAS), 3) plant process water, and 4) recycled water. Chlorine is stored at the Joint Regional Plant as a liquid form of liquefied compressed gas in one ton containers. Liquid chlorine is transferred from the one ton containers to evaporators. The evaporators heat the liquid chlorine to produce chlorine vapor. Th e chlorinators then control the flow of chlorine gas to injectors located at various locations throughout the wastewater treatment plant. The injectors combine chlorine and water to produce chlorine solution providing an effective treatment. A maximum of 10 one ton chlorine containers (20,000 lbs) is maintained in the chlorine room of the chlorine building. This building is located on the north side of the property. HAZARD ASSESSMENT SUMMARY Worst Case Release Result Summary Scenario Description: Release of the maximum quantity of chlorine that can be stored in a vessel - 8,000 pounds in 10 minutes. Although, the only one one-ton container is used at a time at the Joint Regional Plant, four one-ton containers are connected. One entire manifold is active and the other is kept in stand-by status. As the chlorine pressure in the on-line manifold drops, the strength of the negative pressure opens the valve of the standby manifold, allowing the flow of chlorine to remain continuou s. Therefore, in the event of a release upstream of the chlorinators, the total quantity released could be four one-ton containers (8,000 lbs.). In addition, since the one-ton containers are stored enclosed in an enclosed building, passive mitigation measures were incorporated. Consequently, the release rate after the passive measure was calculated to be 440 pounds per minute. The most pessimistic meteorological conditions were used: 1.5 meters/second wind speed, and F stability. Reference table from the EPA's RMP Guidance for Wastewater Treatment Plants was used to determine the distance for the toxic point of 3 ppm. This release reaches off-site and may affect both population and environmental receptors. Alternative Release Result Summary Scenario Description: A release of a chlorine mixture of gas and liquid from 5/16 inch diameter leak. The release rate of chlorine due to the pressure of the tank is 84.4 pounds per minute. However, passive mitigation measures were incorp orated since the chlorine system is located inside an enclosed building at the Joint Regional Plant. Consequently, the release rate after the passive measure was calculated to be 59.6 pounds per minute. The meteorological conditions used were 3 meters per second wind speed, and D stability. Reference table from the EPA's RMP Guidance for Wastewater Treatment Plants was used to determine the distance for the toxic point of 3 ppm. This release reaches off-site and may affect population receptors. No Environmental receptors were affected by the potential release scenario. ACCIDENTAL RELEASE PREVENTION PROGRAM AND CHEMICAL-SPECIFIC PREVENTION STEPS The chlorine system at the Joint Regional Plant has many safety features. Much of the safety of the system is inherent in the policies and procedures that govern the operation of the system. For example, the AWMA/SERRA treatment processes operate in accordance with OSHA's Process Safety Management regulation and the California Accidental Release Prevention (CalARP) Program. In the event that the primary engineering or administration controls at the J. B. Latham Regional Plant fail and cause a release of chlorine, there are several mechanisms in the plant to minimize the impact: 1) chlorine sensors / detectors, 2) alarms, and 3) emergency vapor scrubber system. The chlorine sensors that trigger audible and visual alarms are located in the chlorinator room and the chlorine storage room. Once a chlorine leak of 0.2 ppm is detected by the sensors, the ventilation system that continuously circulates the air in the chlorine building will be shut off by the emergency vapor scrubber system. The chlorine scrubber system then will absorb and will eliminate chlorine. The emergency chlorine scrubber system at the J. B. Latham Regional Plant is also designed and built by RJ Environmental Incorporated. The scrubber system consists three stage chemical absorption system: one horizontal crossflow spray scrubber followed by tw o horizontal crossflow packed bed sections. The released chlorine gas is absorbed and reacted with caustic solution. The system is designed with the ventilation rate of 3000 acfm and the maximum discharge chlorine concentration of 5 ppm. The scrubber has the capability of neutralizing 2,000 pounds of chlorine with a 99%+ rate of effectiveness. In addition, common industry standards, policies, and procedures are utilized to ensure safe practices are being performed. This includes common practices recommended by the Chlorine Institute. FIVE YEAR ACCIDENT HISTORY The accident history researched back five years to June 1994 shows that the AWMA/SERRA's facility has not had an accidental release or "near miss" of chlorine. EMERGENCY RESPONSE PROGRAM The AWMA/SERRA has an emergency response plan in effect at the facility. The Emergency Response Plan (Plan) is detailed in the Emergency Planning and Response section of the PSM/RMP document. This Plan was designed to meet the following objectives: 1.) To save lives. 2.) To minimize and avoid injuries. 3.) To protect the environment. 4.) To minimize property damage. The AWMA/SERRA maintains a safety committee whose members include the emergency coordinators for the facility. The Plan provides the response organization and notification procedures, evacuation routes, and mitigation procedures which will be implemented to respond effectively to emergency situations that may arise at the facility. The Plan also includes the Emergency training for all AWMA/SERRA employees. The AWMA/SERRA performs periodic emergency evacuation drills every 90 days to enhance the emergency response skills of its personnel. The Emergency Response Plan is reviewed and updated by the AWMA/SERRA Joint Regional Plant responsible person, Mr. Michael Wilson at least once a year. This Plan will be review and updated to ensure compliance with the PSM, RMP, and CalARP regulations, and to ensure that the plan is kept current. The AWMA/SERRA h as coordinated emergency response efforts withe the local fire department, Orange County Fire Department. In the case of a chlorine-related emergency, its is the policy of AWMA/SERRA to evacuate the employees and to allow the fire department to respond to the emergency (potentially with the assistance of trained facility personnel). PLANNED CHANGES TO IMPROVE SAFETY The Process Hazard Analysis (PHA) provided the mitigation measures outlined below to improve safety at the AWMA/SERRA Joint Regional Plant. The PHA was comprised of one session that included a HAZOP study, a Plant Walkthrough, a "What-if" analysis, and a series of checklists. The changes will be completed by December 1, 1999. R01 Ensure operating procedures include steps required to evacuate chlorine from expansion chamber and replace rupture disk. Consider having a spare rupture disk. R02 Ensure the ball valve (V-23) closed. Label the ball valve with "For gas use only" tag. R03 Ensure that the fittings in the evaporators are included in the mechanical integrity program with inspection according to manufacturer's recommendation. R04 Examine the applicable code requirements to determine the proper application for the exhaust fans during normal/daily operation (i.e. temperature controlled, always on, etc.). R05 Develop operating procedure for evacuating chlorine from the pipe line for maintenance service. R09 Post floor plans and/or work place maps with evacuation instructions. R10 Consider formal emergency response training for the operators that is at a minimum the Hazardous Materials First Responder Operations level. (See Section 6) Seismic Assessment 1.The missing clamps at the support bracket in the Chlorine Injection Room should be replaced (Photo 2). 2.Determine the feasibility of providing lateral support for the pressure canisters (Photo 3). |