Carbon Canyon Wastewater Reclamation Facility - Executive Summary |
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This document comprises the Risk Management Plan (RMP) for the Inland Empire Utilities Agency (Agency) facility located at 14950 Telephone Avenue (also referred to within the Agency as the Carbon Canyon Wastewater Reclamation Facility, CCWRF). CCWRF occupies 17.91 acres of land directly adjacent to and south of Chino Hills Parkway in the city of Chino, California 91710. Telephone Avenue separates the facility from a group of light industrial and commercial occupancies to the east. Chino Creek runs along the facility's western property line. At the southwest corner of the facility, Chino Creek changes direction to flow southeast, dividing the industrial and commercial occupancies from undeveloped land to the south and east. The Agency also operates two other stationary sources subject to the federal RMP regulations. Separate RMPs have been submitted for those facilities. The purpose of this document is to comply with the risk management planning requirements as set forth in Section 255 35(d) of Article 2 of Chapter 6.95 of the California Health and Safety Code (also known as the California Accidental Release Prevention Program - CalARP) and Part 68 of Title 40 of the Code of Federal Regulations (40CFR Part 68), also known as the federal Accidental Release Prevention Requirements: Risk Management Programs or the federal RMP. The scope of the RMP includes all operations conducted at the CCWRF facility which involve the storage, handling and/or use of chlorine and sulfur dioxide (i.e., chlorine and sulfur dioxide are the only regulated substances which are handled at the facility above the threshold quantity). ES 1.0 DESCRIPTION OF STATIONARY SOURCE AND REGULATED SUBSTANCES HANDLED Since its inception, the Inland Empire Utilities Agency has evolved with the growth and needs of the western portion of San Bernardino County. Today, the Agency distributes imported water and provides municipal/industrial wastewater collection and treatment services for a 242-square mile a rea that includes more than 600,000 people. CCWRF has been in operation since 1992 and serves the cities of Chino, Chino Hills, Ontario, Rancho Cucamonga, Upland, Montclair, Fontana and some unincorporated portions of San Bernardino County in California. The primary operation conducted at CCWRF is wastewater treatment. As a part of this process, chlorine is utilized for water disinfection and sulfur dioxide is utilized for dechlorination. Provided below, is a brief description of the primary operations conducted at the facility and a description of the storage, handling and use of chlorine and sulfur dioxide. PRIMARY OPERATIONS Figure ES-I provides a simplified process flow diagram for the wastewater treatment process at CCWRF. As shown, raw sewage is passed through screening and grit removal units, primary clarifiers, aeration basins, secondary clarifiers, polymer and coagulant chemical addition, effluent filters, chlorination and dechlorination units and then discharged. The plant effluent is discharged to Chino Creek and onto the Santa Ana River. CCWRF contains six aeration basins, two primary clarifiers, three secondary clarifiers, tertiary filters, a maximum of sixteen one ton containers of chlorine, and a maximum of eight one ton containers of sulfur dioxide. STORAGE, HANDLING AND USE OF CHLORINE CCWRF Chlorination Process Description At CCWRF, the quality of water is monitored via sampling of the process. Chlorine is utilized to disinfect cleaned/treated water prior to discharging (this is also known as final disinfection of the effluent). Chlorine is a regulated substance subject to the federal RMP requirements. The CCWRF chlorination process consists of four main components: A maximum of sixteen one-ton containers of chlorine; Two evaporator for converting liquid chlorine to a gaseous state; Three chlorinators and three ejectors to control the injection of chlorine and maintain a vacuum on the gaseous chlorine system; and System piping. One ton containers containing liquid chlorine are delivered to the facility via truck and stored. Liquid chlorine is then withdrawn from the containers and transferred to the evaporators under pressure. The evaporator provides the heat necessary to vaporize chlorine (the evaporator is a heat exchanger, which circulates hot water through a jacket around the chlorine evaporation chamber). The chlorine gas generated by the evaporator is transferred to the chlorinator under a vacuum and injected into water (now referred to as chlorine solution). The vacuum, from the evaporator to the injection point, is maintained by the ejectors. As a result of having chlorine injected into it, the water contains elevated levels of diluted chlorine. This chlorine solution is then transferred via piping to the five end use point where it is mixed with the water to be treated. Emergency Scrubber The Agency has installed an emergency chlorine/sulfur dioxide scrubber. This unit is connected to the building (where both chlorine and sulfur dioxide systems are housed). Under emergency conditions, an induced draft fan pulls the chlorine vapor (released into the building) through the scrubber, where intimate contact with a re-circulating solution of sodium hydroxide (i.e., 50-percent concentrated sodium hydroxide) results in complete absorption and removal of chlorine vapor. The unit has the capacity to scrub up to 4000 pounds of chlorine and is activated via either automatic leak detectors (i.e., chlorine sensors located within the building) or a manual remote start switch. STORAGE, HANDLING AND USE OF SULFUR DIOXIDE CCWRF Dechlorination Process Description At CCWRF, the residual chlorine content of the disinfected waster is monitored via sampling of the process. Sulfur dioxide is utilized to eliminate the residual chlorine content in the disinfected water. Sulfur dioxide is a regulated substance subject to the federal RMP requirements. The CCWRF dechlorination process consists of four ma in components: A maximum of eight one-ton containers of sulfur dioxide; Two evaporators for converting liquid sulfur dioxide to a gaseous state; Two sulfonators and two ejectors to control the injection of sulfur dioxide and maintain a vacuum on the gaseous sulfur dioxide system; and System piping. One ton containers containing liquid sulfur dioxide are delivered to the facility via truck and stored. Liquid sulfur dioxide is then withdrawn from the containers and transferred to the evaporators under pressure. The evaporator provides the heat necessary to vaporize sulfur dioxide (the evaporator is a heat exchanger, which circulates hot water through a jacket around the sulfur dioxide evaporation chamber). The sulfur dioxide gas generated by the evaporator is transferred to the sulfonators under a vacuum and injected into water (now referred to as sulfur dioxide solution). The vacuum, from the evaporator to the injection point, is maintained by the ejectors. As a result of h aving sulfur dioxide injected into it, the water contains elevated levels of diluted sulfur dioxide. This sulfur dioxide dilution water is then transferred via piping to the end use point where it is mixed with the water to be treated. Emergency Scrubber The Agency has installed an emergency chlorine/sulfur dioxide scrubber. This unit is connected to the building (where both chlorine and sulfur dioxide systems are housed). Under emergency conditions, an induced draft fan pulls the sulfur dioxide vapors (released into the building) through the scrubber, where intimate contact with a re-circulating solution of sodium hydroxide (i.e., 50-percent concentrated sodium hydroxide) results in complete absorption and removal of sulfur dioxide vapor. The unit has the capacity to scrub up to 4000 pounds of sulfur dioxide and is activated via either automatic leak detectors (i.e., chlorine sensors located within the building) or a manual remote start switch. ES 2.0 ACCIDENTAL RELEASE SCENARIOS The RMP regulations require that at least two types of release scenarios be evaluated for their potential to impact off-site populations: the worst case release; and an alternative release (that is more credible). A number of hypothetical accidental release scenarios were postulated and evaluated for the RMP. These scenarios were categorized into worst-case release scenarios and alternative release scenarios. Each of these categories of hypothetical accidental release scenarios is discussed below. CHLORINE Worst-Case Release Scenario In this scenario, one of the one-ton containers of chlorine on site experiences a catastrophic failure due to an unknown external event. This scenario would be initiated by some unknown external event (i.e., an airplane, missile or meteorite impacting the chlorine building where the ton containers are located). It is highly improbable that this scenario would be initiated by a seismic event. The chlorine building has been constructed to the requ ired Uniform Building Code and Uniform Fire Code specifications. However, the possibility of this scenario being initiated by a seismic event can not be completely discarded. This scenario is considered to be extremely unlikely. In the highly unlikely case that this scenario occurs, approximately 2,000-pounds of chlorine would be released. The release of chlorine could occur outdoors or indoors. The release of the chlorine within the chlorine building would result in the chlorine sensors detecting the chlorine and activating the emergency scrubber exhaust fan. This would result in the "sucking up" of chlorine vapors from the building and being routed to the emergency scrubber. The emergency scrubber was designed for the purpose of mitigating the effects of accidental releases of chlorine. Although the emergency chlorine scrubber was installed by the Agency for the specific purpose of mitigating the potential off-site consequences of accidental chlorine releases (such as those describ ed above), the presence of the chlorine scrubber system was not taken into account in evaluating the off-site consequences. Rather, it was assumed that the chlorine released during the catastrophic accident was released outdoors forming a cloud of chlorine vapor. The resulting vapor cloud was assumed to freely migrate off-site. Utilizing the methodology specified by USEPA, the estimated vulnerable zone for this accidental release scenario is approximately 1.3-miles. Figure ES-2 presents a graphical representation of the vulnerable zones for the worst-case release scenario for accidental releases involving chlorine. Also presented in Figure ES-2 are the sensitive receptors located within one-mile of the facility. Table ES-I provides a listing of sensitive receptors located in close proximity to the facility. Alternative Release Scenarios Alternative release scenarios which are considered to be more likely to occur are those which may result in the release of anywhere from less than o ne-pound to up to 1000-pounds of chlorine. These scenarios include situations such as delivery of a leaking one-ton container of chlorine to the facility, a pinhole leak in the chlorine transfer piping and a partial or complete failure of the liquid or vapor chlorine transfer lines at various points in the system (either in-doors or out-doors). In order to be conservative in the estimation of the vulnerable zone, it was assumed that 1000-pounds of chlorine was released during an accident involving the complete failure of a liquid transfer line from a one ton container. It was further assumed that the material was released directly outdoors. Since the release can occur out-doors (i.e., outside of the chlorine storage building) neither the system enclosure provided by the chlorine building nor the emergency scrubber system were taken into account in evaluating the off-site consequences. Utilizing this assumption is much more conservative in nature and resulted in the estimation of the la rgest vulnerable zone for these types of accident scenarios. The resulting toxic gas (i.e., chlorine) vapor cloud was assumed to freely migrate off-site. Utilizing the methodology specified by USEPA, the estimated vulnerable zone for these types of scenarios is approximately 0.5 miles. Figure ES-2 presents a graphical representation of the vulnerable zones for the alternative release scenario for accidental releases involving chlorine. Also presented in Figure ES-2 are the sensitive receptors located within one-mile of the facility? Table ES- I provides a listing of sensitive receptors located in close proximity to the facility. SULFUR DIOXIDE Worst-Case Release Scenario In this scenario, one of the one-ton containers of sulfur dioxide on site experiences a catastrophic failure due to an unknown external event. This scenario would be initiated by some unknown external event (i.e., an airplane, missile or meteorite impacting the sulfur dioxide building where the ton containers are l ocated). It is highly improbable that this scenario would be initiated by a seismic event. The sulfur dioxide building has been constructed to the required Uniform Building Code and Uniform Fire Code specifications. However, the possibility of this scenario being initiated by a seismic event can not be completely discarded. This scenario is considered to be extremely unlikely. In the highly unlikely case that this scenario occurs, approximately 2,000-pounds of sulfur dioxide would be released. The release of sulfur dioxide could occur outdoors or indoors. The release of the sulfur dioxide within the building would result in the sulfur dioxide sensors detecting the sulfur dioxide and activating the emergency scrubber exhaust fan. This would result in the "sucking up" of sulfur dioxide vapors from the building and being routed to the emergency scrubber. The emergency scrubber was designed for the purpose of mitigating the effects of accidental releases of sulfur dioxide. Although the e mergency scrubber was installed by the Agency for the specific purpose of mitigating the potential off-site consequences of accidental sulfur dioxide releases (such as those described above), the presence of the scrubber system was not taken into account in evaluating the off-site consequences. Rather, it was assumed that the sulfur dioxide released during the catastrophic accident was released outdoors forming a cloud of sulfur dioxide vapor. The resulting vapor cloud was assumed to freely migrate off-site. Utilizing the methodology specified by USEPA, the estimated vulnerable zone for this accidental release scenario is approximately 1.3-miles. Figure ES-2 presents a graphical representation of the vulnerable zones for the worst-case release scenario for accidental releases involving sulfur dioxide. Also presented in Figure ES-2 are the sensitive receptors located within one-mile of the facility. Table ES-I provides a listing of sensitive receptors located in close proximity to the facility. Alternative Release Scenarios Alternative release scenarios which are considered to be more likely to occur are those which may result in the release of anywhere from less than one-pound to up to 1000-pounds of sulfur dioxide. These scenarios include situations such as delivery of a leaking one-ton container of sulfur dioxide to the facility, a phole leak in the sulfur dioxide transfer piping and a partial or complete failure of the liquid or vapor sulfur dioxide transfer lines at various points in the system (either in-doors or out-doors). In order to be conservative in the estimation of the vulnerable zone, it was assumed that 1000-pounds of sulfur dioxide was released during an accident involving the complete failure of a liquid transfer l*ne from a one ton container. It was further assumed that the material was released directly outdoors. Since the release can occur out-doors (i.e., outside of the sulfur dioxide storage building) neither the system enclosure provided by the building nor the emergency scrubber were taken into account in evaluating the off-site consequences. Utilizing this assumption is much more conservative in nature and resulted in the estimation of the largest vulnerable zone for these types of accident scenarios. The resulting toxic gas (i.e., sulfur dioxide) vapor cloud was assumed to freely migrate off-site. Utilizing the methodology specified by USEPA, the estimated vulnerable zone for these types of scenarios is approximately 0.2 miles. Figure ES-2 presents a graphical representation of the vulnerable zones for the alternative release scenario for accidental releases involving chlorine. Also presented in Figure ES-2 are the sensitive receptors located within one-mile of the facility. Table ES- I provides a listing of sensitive receptors located in close proximity to the facility. ES 3.0 FIVE YEAR ACCIDENT HISTORY During the five years preceding the submittal of this RMP, the facility has NOT had any releases of regulated su bstances which have resulted in: Onsite deaths, injuries, or significant property damage; or Known offsite deaths, injuries, property damage, environmental damage, evacuations, or sheltering in place. ES 4.0 ACCIDENTAL RELEASE PREVENTION PROGRAM AND CHEMICAL SPECIFIC PREVENTION STEPS The Accidental Release Prevention Program at the Agency consists of a series of programs, procedures and policies designed to minimize the risk of accidental releases involving regulated substances handled at the facility (i.e., the only regulated substances handled at the facility are chlorine and sulfur dioxide). These programs include design and operating controls such as compliance with specified codes, the health and safety program, numerous standard operating procedures, the equipment inspection and maintenance program (including a mechanical integrity and preventive maintenance program), site security, the management of change program, pre-start-up review, fire prevention/fire protection/hot work permit program, management of and safety of- contractors, accident/incident investigation procedures, emergency response plan, RMP compliance auditing program, record keeping and a variety of training programs. Details of each of these components of the Agency's Accidental Release Prevention Program are provided in the document entitled Risk Management Plan (RMP), Volume I - Prevention Program. There are several chlorine and sulfur dioxide leak detection and monitoring devices and other protective devices (e.g.., for fire protection, etc.) placed at strategic locations throughout the facility. Table ES-2 provides a summary listing of these detection and monitoring devices as well as the* sensitivities. ES 5.0 EMERGENCY RESPONSE The Agency recognizes that emergency planning and emergency response are an integral component of risk management. As such, the Agency currently has emergency action plans and emergency evacuation plans in place. In addition, the Agency has developed a Fire Prevention Plan. These programs work together to mitigate the effects of unplanned releases or events. However, as a measure to improve safety, the Agency is currently developing a specific response program for emergencies involving chlorine and sulfur dioxide. The Agency is planning to conduct a joint emergency response drill with the San Bernardino County Interagency Hazardous Materials Response Team. This will ensure that key agencies which could be involved in emergency response at the Agency are familiar with the facility operations and hazards and are also familiar with the capabilities of Agency personnel (from an emergency response view point). In addition, these drills will ensure that the existing emergency response plan is evaluated during the drilling process for its functionality, practicality and effectiveness. Based on these drills changes and modifications may be made (as appropriate) to improve response efficiencies. ES 6.0 PLANNED CHANGES TO IMPROVE SAFETY A d etailed hazard and operability study (i.e., hazards analysis) was performed on ALL operations involving chlorine and sulfur dioxide in order to evaluate the potential for accidental releases. As a result of this hazards analysis a number of recommendations were made to improve the safety of the operations conducted. The recommended actions are summarized in Table ES-3. Table ES-3 also presents the implementation status of the recommended actions. As shown, the Agency has already implemented a number of the recommendations. Table ES-3 also presents the expected date of implementation for those recommendations not yet implemented. ES 7.0 FOR MORE INFORMATION The Agency recognizes that some persons may be interested in obtaining more detailed information regarding risk management prevention program components not discussed herein. Interested parties that have additional questions regarding the Agency's Risk Management Plan, are directed to contact: Mr. Sean R Denman Inland Empire Utili ties Agency 9400 Cherry Avenue, Building A Fontana, California 92335 |