Barstow Water Reclamation Facility - Executive Summary |
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Executive Summary Introduction Chemicals are widely used in industry, in the home, in the environment. They are transported on roads, water, and railways. We at the Barstow Water Reclamation Facility (Barstow WRF) use chemicals, too. For example, we use chlorine to disinfect our water to provide safe water discharges to the environment or for landscaping or irrigation uses, and we use sulfur dioxide to remove excess chlorine in a final polishing stage of treatment. Storing large qualities of chlorine and sulfur dioxide can be a hazard. We take our safety obligations in storing and using these chemicals as seriously as we do take providing the environment safe disinfected water. The following document describes what could happen if there were to be an accident, the steps we take everyday to ensure a safely operating plant, and what to do in event of an emergency. Accidental Release Prevention and Emergency Response Policies The City of Barstow and Barstow WRF accidental relea se prevention policy involves a unified approach that integrates proven technology, trains staff on operation and maintenance practices, and uses tested management system practices. All applicable procedures of the State of California and U.S. Environmental Protection Agency (EPA) Prevention Program are adhered to, including key elements such as training, systems management, and emergency response procedures. This document complies with the U.S. Environmental Protection Agency's (EPA's) Risk Management Program, under Section 112 (r) of the Clean Air Act (CAA) Amendments of 1990, 40 Code of Federal Regulations (CFR) Part 68 and the California Accidental Release Prevention (CalARP) Program under California Code of Regulations (CCF) Title 19, Division 2, Chapter 4.5. The Barstow WRF has a chlorination system that uses chlorine gas fed from 1-ton chlorine containers. This document summarizes our existing health and safety programs, our internal management response team, policies, pr ocedures, and on-going actions that are designed to prevent or minimize impacts of accidental releases of chlorine to the environment. The Barstow WRF has prepared an emergency action plan to handle any potential accidental releases and to safeguard both on- and off-site people. To date, we have had an excellent record in preventing accidents from occurring. General Facility and Regulated Substances Information The Barstow Water Reclamation Facility is wastewater treatment and reclamation plant located at 2200 East Riverside Avenue in the City of Barstow, California. The facility, located on approximately 200-acre property, is just north of Interstate 40, south of the Mojave River and on the east side of Barstow. Approximately 160 acres of the property is used for agriculture. Barstow WRF, operating since 1968, currently stores chlorine, a regulated toxic substance under RMP and CalARP. Chlorine is stored in four 1-ton chlorine containers. This chlorine storage exceeds the liste d threshold quantities in the RMP and CalARP rules. The chlorination system at Barstow Water Reclamation Facility injects chlorine gas into a solution that is used for several processes, primarily for final effluent disinfection in the chlorine contact chamber. A vacuum is created in an ejector that pulls the gaseous chlorine from the 1-ton container through a tank-mounted chlorinator that controls and measures the flow of gaseous chlorine. The gaseous chlorine is mixed with utility water from the chlorine contact chamber, and the solution is distributed to several locations in the plant. In addition to effluent disinfection in the chlorine contact chamber, chlorine solution can be piped to the aeration basins for filamentous control. The chlorine system at Barstow WRF is a vacuum operated system, in which means the chlorine gas is pulled from the container as a result of the vacuum created by the injector. A break in the piping or any other loss of vacuum causes the system to fa il close, with a potential to release only minute quantities of chlorine. Chlorine leak detectors monitor continuously for leaks in the storage area and in the injector room. The chlorine leak detector is a self-contained, electrically operated device designed to detect 0.7 ppm by volume of chlorine in the air. If a leak occurs, a chlorine level of 0.7 ppm will turn on a red warning light on top of the building and an audible alarm. The detector also sends a signal to the central computer system that activates an alarm on the annunciator board in the operations building. During evenings and weekends, the alarm will activate a pager system , notifying on-call staff. All ton chlorine containers are equipped with fusible metal type safety relief devices, called fusible plugs. Most ton containers have six fusible plugs, three at each end, spaced 120 degrees apart. In the event of a fire or other high temperatures, the fusible plug is designed to melt between 150 F and 165 F to rel ieve pressure and prevent a catastrophic rupture of the container. An emergency shower and eye wash station are provided at each building along with smoke alarms. Access to the Barstow Water Reclamation Facility from Riverside Avenue is controlled by a gate, which is locked at night. The Chlorine Building remains locked when not in use. Offsite Consequence Analysis Results The offsite consequence analysis includes consideration of two release scenarios, identified as "worst case" and "alternative" release scenarios. The worst-case scenario requires that a release of the entire contents of the single largest vessel or pipe be evaluated for off-site impacts. Only passive or administrative controls are allowed under this scenario to reduce off-site impacts. The scenario used for Barstow WRF is the rupture of a 1-ton chlorine container, resulting in a release of 2,000 pounds of chlorine over a 10-minute duration. Because the chlorine containers are unloaded outside, passive mitigati on provided by the building could not be considered. The release rate will, accordingly, be 200 pounds per minute (lbs./min). In practice this type of total release of a 1-ton container would be unlikely and never occur during the lifetime of the plant. The released liquid is assumed to quickly volatilize and to disperse as a vapor cloud. The distance to the toxic endpoint was estimated using the DEGADIS 3.0.3. The toxic endpoint was conservatively set by EPA to ensure public notification and that local emergency respond planning takes into account the greatest possible impacted area surrounding the release point. The toxic endpoint selected by EPA and CalARP was 3 ppm. In addition all required EPA-model input parameters where included in completing this activity, including conservative meteorological conditions - Stability F class, wind speed of 1.5 meters per second maximum ambient temperature of 460 C, and average humidity (51%). The results of the dispersion modeling analysis for this worst case release scenario indicate that this scenario has an offsite impact. The alternative release scenario is a more likely release scenario compared to the worst-case release scenario. Unlike the worst case release scenario, active controls can be applied to minimize the leak or impacts. Active controls consist of mechanical, electrical, or human input. Based on the process hazard analysis performed for the chlorine system, the alternative release scenario described below was chosen. The alternative release scenario selected for the Barstow WRF chlorine system is a vacuum regulator/diaphragm failure on the tank-mounted chlorinator. The release rate is determined for a chlorine vapor release from the Handbook of Chlorination equations adapted from the Chlorine Institute . The vent orifice size (0.14 inch) for the vacuum regulator is a typical value obtained from the manufacturer. This scenario assumes that the release occurs for 10 minutes. The release rate for this s cenario is 1.3 lb/min. The toxic endpoint selected by EPA and CalARP was 3 ppm. In addition all required EPA-model input parameters where included in completing this activity, including the following meteorological conditions - Stability D class, wind speed of 3.0 meters per second, average temperature of 180 C, and average humidity (51%). The results of the dispersion modeling analysis for this alternative release scenario indicate that this scenario has an offsite impact. Finally, no chlorine or sulfur dioxide releases that could have cause safety or health hazard (no deaths, injuries, property or environmental damage, evacuations, or sheltering in place) occurred at Barstow WRF during the last five years. Some minor, incidental releases may have occurred over this period, but they were quickly handled by staff, were neutralized, or posed no safety or health hazards. Summary of the Accidental Release Prevention Program and Chemical-specific Prevention Steps Barstow WRF is in c ompliance with Federal and State Process Safety Management (PSM) requirements. Chemical-specific prevention steps include availability of self-contained escape breathing apparatus, worn by the operators during connection and disconnection of the chlorine supplies, awareness of the hazardous and toxic properties of chlorine, and the presence of chlorine detectors and alarms. Barstow WRF accidental release prevention program is based on the following key elements: 7 Detailed management system and clear levels of responsibilities and team member roles 7 Comprehensive safety process information that is readily available to staff, emergency responders, and contractors 7 Comprehensive preventive maintenance program 7 A process hazard analysis of equipment and procedures with operation and maintenance staff participation and review 7 Use of state-of-the-art process and safety equipment 7 Use of accurate and effective operating procedures, written with operations and maintenance staff parti cipation 7 High level of training of operators and maintenance staff 7 Implementation of an incident investigation, inspection, and auditing program using qualified staff. Process and Chemical Safety Information Comprehensive chemical data have been assembled to include regulatory reporting and action thresholds, health hazard, and chemical exposure limitations, as well as detailed physical properties of each regulated substance. This information was compiled from numerous sources and is intended to be a one-stop source for the reader seeking data about these substances. This information includes chlorine background information, MSDS sheets, and chlorine reaction chemistry. Equipment safety information has been compiled on the chlorine process, and specifications for the process are collected in one place for easy reference. Details such as maximum intended inventory; safe upper and lower temperatures; safe upper and lower pressures; and codes and standards used to design, build, and operate the processes are on file at the facility. We also have scheduled reviews of our risk management program and process safety management plan to update safety information if there is a major change that makes existing information inaccurate. Process Hazard Analysis On March, 17, 1999, a detailed process hazard analysis (PHA) was conducted with facility maintenance, engineering, and management staff for the regulated process. The team consisted of process operating and maintenance experts and process design engineers. The PHA technique used was the "What If Analysis", per acceptable approach guidance from EPA. The PHA was led by a knowledgeable person on the type of process being reviewed. This review will be updated again within a five-year period or whenever there is major change in the process. A list of actions to resolve any found significant hazard analysis findings was prepared and staff is currently working to resolve this action item list. Staff will docume nt completion of any action item. A seismic walkthrough was recently completed, and recommendations were provided to Barstow WRF for their evaluations and implementation. Operating Procedures Barstow WRF maintains up-to-date, accurate, written operating procedures that give clear instructions for the chlorine process. Barstow WRF ensures effective operating practices by combining them with operating and maintenance training programs. Standard operating procedures (SOPs) provide system descriptions, specifications, equipment inspection requirements, and operating procedures for the chlorine system. Procedures include startup, shutdown, and normal, emergency operations. Also included are maintenance and troubleshooting procedures, including consequences of deviation and the steps to avoid correct deviations. Barstow WRF will update procedures whenever a change occurs that alters the steps needed to operate safely. Operating procedures will be developed and in place prior to an y new process equipment coming on line or a changed process starting back up. Operations and Maintenance Training Program Each Barstow WRF employee presently involved in operating or maintaining the chlorine process is trained in an overview of the process and detailed, applicable operating and maintenance procedures. This training helps employees understand nature and cause of problems arising from operations involving chlorine, and increases employee awareness of their hazards. Barstow WRF's training program includes both initial and refresher training that covers 1) a general overview of the processes, 2) the properties and hazards of the substances in the process, and 3) a detailed review of the process operating procedures and safe work practices. Oral reviews and written self-evaluations are used to verify that an employee understands the training material before the process work can be resumed. Training documentation includes: date of most recent review or revision to the training program, type of training required and the type of competency testing used to ensure staff understands the training, and an on-going employee training record. Contractors Barstow WRF has procedures and policies in place that ensure that only contractors with good safety programs are selected to perform work on and around the chlorine processes. Contractors are properly informed of the hazards, access limitations to these process areas, and emergency response procedures, and must be prepared to safely complete the work. Barstow WRF sets minimum contractor safety performance requirements to do work in process areas, holds contractor safety briefings before allowing them near or in the process area; controls access to the process areas, and evaluates the contractor's performance. Pre-Startup Safety Review and Mechanical Integrity Program Barstow WRF ensures that a pre-startup safety review is completed for any new regulated process at the plant, or for significant modific ations to an existing covered process that requires a change in the process safety information. Barstow WRF maintains the mechanical integrity of process equipment to help prevent equipment failures that could endanger workers, the public, or the environment. Barstow WRF believes that this program is the primary line of defense against a release. Maintenance staff address equipment testing and inspection, preventative maintenance schedules, and personnel training of these procedures. Barstow WRF's mechanical integrity program includes the following: 7 Written procedures for maintaining mechanical integrity through inspection and testing of process equipment, based on instructions of equipment vendors, industry codes, and prior operating experience; 7 Implementation of the written procedures by performing inspections and tests on process equipment at specified intervals; 7 Training of maintenance personnel in procedures for safe work practices such as lockout/tagout, line or equip ment opening, and avoidance and correction of unsafe conditions; and 7 Procedures specifying training requirements for contract maintenance employees, as well as requiring contractors to use plant developed maintenance procedures for process areas. Hot Work Permits and Management of Change Barstow WRF requires employees and contractors to employ safe work practices when performing "hot work" in, on, or around the regulated processes. Barstow WRF uses a comprehensive permitting and training program to ensure hot work is conducted safely. Barstow WRF provides a system and approach to maintain and implement any management of changes or modifications to equipment, procedures, chemicals, and processing conditions. This system allows Barstow WRF employees to identify and review safety hazards or provide addition safety, process, or chemical information to existing data before the propose change would either comprise system safety or need training to be completed. Internal Compliance Audits Internal compliance audits are conducted every 3 years to verify compliance with the programs and procedures contained in the RMP. Barstow WRF assembles an audit team that includes personnel knowledgeable in the Risk Management Program rule and in the regulatory process. This team evaluates whether the prevention program satisfies the requirements of the Risk Management Program rule and whether the prevention program is sufficient to help ensure safe operation of the process. The results of the audit are documented, recommendations are resolved, and appropriate enhancements to the prevention program are implemented. Incident Investigation Barstow WRF investigates all incidents that could reasonably have resulted in a serious injury to personnel, the public, or the environment so that similar accidents can be prevented. Barstow WRF trains employees to identify and report any incident that requires investigation. An investigation team is assembled and the investigation is initiated within 48 hours of the incident. The results of the investigation are documented, recommendations are resolved, and appropriate process enhancements are implemented. Information found during the investigation is reviewed by appropriate staff and is added to or used to revise operating and maintenance procedures. Information from audits and any resulting changes in operating procedures are passed onto the training unit for their inclusion in existing training programs, if warranted to prevent a future event. Five-year Accident History Summary No chlorine releases that could have cause safety or health hazard (no deaths, injuries, property or environmental damage, evacuations, or sheltering in place) have occurred at Barstow during the last five years. Emergency Response Program Summary Barstow WRF has established a written emergency action program that is followed by the employees to help safely control accidental releases of hazardous substances. This program has bee n coordinated (reviewed) by the San Bernardino Fire Department, which is a member of the Local Emergency Response Planning Committee (LEPC). This program includes an emergency action and notification plan. Emergency operation and action procedures are also reviewed once per year. Planned Changes to Improve Safety In the March 1999 process hazardous analysis, a number of additional changes were identified to improve the safety of the chlorination system. It is expected that most of the recommended actions will be evaluated and implemented by December 1999. The implementation of these recommendations will further improve the safety of the chlorine process. |