Wastewater Treatment Plant 1 Station - Executive Summary |
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RISK MANAGEMENT PLAN FALLBROOK PUBLIC UTILITY DISTRICT WASTEWATER TREATMENT PLANT 1 STATION 1425 S. ALTURAS STREET FALLBROOK, CA 92028 SECTION 1: EXECUTIVE SUMMARY This risk management plan addresses the risk management program for Fallbrook Public Utility District Wastewater Treatment Plant 1 Station. This plan applies to the process conducted to store chlorine gas cylinders and to chlorinate recycled water from sewage treatment within the district. Section 112(r) of the Clean Air Act and 1990 Amendments requires a risk management plan and program be developed for regulated substances used above certain thresholds within a process that could lead to an accidental release. The U.S. Environmental Protection Agency (EPA) implements the Federal Clean Air Act by Title 40, Code of Federal Regulations (CFR), Part 68. In turn, Title 19 of the California Code of Regulations on Public Safety implements the Federal requirements with certain additions specific to the state. The EPA h as delegated its authority to the state and local regulatory agencies. As such, the State of California has established threshold levels that are lower (more stringent) than the Federal thresholds. Fallbrook Public Utility District's Wastewater Treatment Plant 1 Station inventory of chlorine gas [Chemical Abstracts Service (CAS) number 7782-50-5] cylinders is above the Federal and State regulatory threshold. This plan is prepared in compliance with the San Diego County Department of Environmental Health, Hazardous Materials Division, "California Accidental Release Prevention Program (CalARP) Guidelines" (revised February 25, 1999). This plan shall be reviewed annually and updated at least every 5 years. This plan is intended to describe the responsibilities and activities necessary to respond to an accidental release of chlorine gas to personnel, the public, and the environment. This plan is made available to the public and the local emergency responders (e.g., North County Fire Protection District, and California Division of Forestry). The Standard Industrial Classification (SIC) Code for this district is 4941(water supply), and the North American Industrial Classification System (NAICS) Code is 221310 (water and wastewater treatment). Fallbrook Public Utility District has established a chlorine-handling procedure, emergency plan, and training program that ensures the safety of personnel, the public, and the environment. This plan addresses emergency response and accident prevention. The chlorine handling procedure covers the safety aspects of changing chlorine cylinders and storage. The hazardous material training programs consist of hazard identification, proper handling of chlorine cylinders, safety precautions, use of Material Safety Data Sheets (MSDS), daily visual inspections, work orders, and corrective maintenance services. The program also provides for training as first responders and hazardous material (HAZMAT) technician-level mitigation specialists. The program implements the elements of the California Occupational Safety and Health Administration (OSHA) Process Safety Management standards. A process hazard evaluation has been performed and will be updated at least once every five years or whenever there is a new hazard or risk created by changes at the Wastewater Treatment Plant 1 Station. The Fallbrook Public Utility District was established as a political subdivision of the State of California in 1922 and operates under the provisions of the Public Utility District Act, Division 7, of the Public Utility Code as adopted in 1953. The public utility district was needed for the prime purpose of supplying water to the town of Fallbrook and the surrounding residential and agricultural areas. The Fallbrook Public Utility District encompasses approximately 27,963 acres (43.7 square miles) that includes district-owned watershed lands. Wastewater Treatment Plant 1 is located near Fallbrook Creek and has an estimated population of 28,000 residents (see Figure 1-1). The District serves approximately 7,400 water connections on a regular basis. In November 1994, the citizens of the Fallbrook Sanitary District voted to dissolve that district and have Fallbrook Public Utility District become the provider of sewer services in Fallbrook. Therefore, the District provides both water and sewer services. The District serves approximately 4,000 sewer connections. The District's boundaries are adjoined by the Rainbow Municipal Water District, the Camp Pendleton Military Reservation, Riverside County, and the U.S. Naval Weapons Station at Fallbrook (see Figure 1-2). Figure 1-2 shows De Luz Heights Municipal Water District which has merged with Fallbrook Public Utility District, and is now part of the District. Live Oak County Park is approximately 1 mile from the District's boundary. The area is unique in many ways due to its varying elevations and high rate of irrigation. Average rainfall per year i s approximately twenty-seven (27) inches. The District is governed by a five (5) member board of directors. Regular meetings of the board of directors are held monthly. Registered voters of the District elect the directors to office for a term of four (4) years. The District utilizes outside consultants on a continuous, as needed basis for operational and environmental concerns. The District headquarters is located on 990 East Mission Road and there are four chlorine injection sites (see Figure 1-3). Full one-ton (2,000 pound capacity) chlorine gas cylinders are routinely delivered to the chlorine injection site by an offsite chemical supplier. The chlorine injection sites include the Wastewater Treatment Plant 1 Station, Red Mountain Station, Rock Mountain Station, and Pala Mesa Station. Two of these sites, Wastewater Treatment Plant 1 and Red Mountain, have one-ton chlorine gas cylinders that exceed the EPA threshold quantity. The Wastewater Treatment Plant 1 Station has fou r (4) one-ton cylinders on-line and four (4) one-ton cylinders stored on-site. The Red Mountain Station has two (2) one-ton cylinders on-line and four (4) one-ton cylinders stored on-site. A separate Risk Management Plan will be prepared for this site to address the Federal requirements. Rock Mountain and Pala Mesa Stations have 150-pound cylinders on-site that exceed the State threshold quantity. A separate Risk Management Plan will be prepared to address these sites, as agreed upon by the San Diego County Department of Environmental Health, Hazardous Materials Division. Figure 1-4 shows the Wastewater Treatment Plant 1 Station layout. When the cylinders are empty, District personnel pick up the cylinders and replace the empty ones with full ones stored on-site. The empty cylinders are stored temporarily at the site and picked up by the offsite chemical supplier in exchange for new full cylinders. Personnel mark the used-cylinders "empty" or "partial" in the storage area i n order to distinguish them from the full or new cylinders that are used on-line. Administrative controls are in place to ensure safe storage and handling. No more than eight (8) full one-ton cylinders are stored onsite at the Wastewater Treatment Plant 1 Station. The chlorine gas cylinders are stored on a concrete pad that is enclosed by a concrete-block building. Usage rates vary from one month to several months, up to one year for each station. An emergency chlorine wet scrubbing system is installed that minimizes the release of chlorine gas to the environment. The system consists of an ejector-venturi scrubber, caustic storage tank, and mist eliminator pad that effectively remove chlorine gas and odors through absorption and chemical reaction between the gas and scrubbing liquid. An offsite-consequence analysis, using the worst-case scenario for an accidental release of chlorine gas is provided in Section 4 of this plan. The worst-case scenario consists of failure of a fu ll one-ton chlorine gas cylinder, releasing chlorine gas at ground level over a ten (10) minute period. The distance to the toxic endpoint of 0.0087 milligrams per liter is 3 miles for the one-ton cylinder. This release is based on worst-case weather conditions, outdoor operations, and is the distance at which chlorine gas no longer poses a hazard to the public. The worst-case release scenario is modeled using the methodology identified in the U.S. Environmental Protection Agency (EPA), "Risk Management Program Guidance For Wastewater Treatment Plants", EPA 550-B-98-010. The chlorine gas cylinders are designed to withstand a 45 miles per hour (mph) impact. Also, an alternate scenario that is more likely to occur than the worst-case release scenario is provided in this section. The alternate release scenario consists of a small valve leak on a full chlorine gas cylinder with mitigation measures in place. The alternate release scenario is modeled using the EPA air dispersion m odel T-SCREEN( (Version 3.0, Britter-McQuaid model, 1992). The distance to the toxic endpoint is 3 miles for the one-ton cylinder. Passive mitigation measures, such as a wet scrubber system and concrete-block enclosure, are accounted for in the release scenario. Administrative controls and procedures are in place to quickly identify problems associated with leaking cylinders. Leaking cylinders are repaired in a timely manner in order to minimize releases. Proper chlorine gas handling procedures are in place to ensure safe handling, loading and off-loading by operations personnel. A chlorine emergency repair kit is used to contain any valve leaks detected during normal operations. Visual and audible chlorine alarm/detection systems are installed at the site and are connected to a telemetry system for standby personnel. Employee training and HAZMAT personal protective equipment are available and are used to safely repair this kind of problem. Work orders are prepared by pe rsonnel to ensure that safety equipment maintenance and repair are properly completed in a timely manner. An offsite contractor conducts annual inspections and repair services of the Fallbrook Public Utility District facilities. An effective training program for employees and participation in simulated exercises or drills ensures management's commitment to general release prevention. There have been no accidents or anyone offsite injured as a result of a chlorine gas release within the past five (5) years of operation. No "hot work" involving electric or gas welding, cutting, brazing, or similar flame/spark-producing operation is performed on the chlorine gas cylinders. Additional training on the Fallbrook Public Utility District's risk management program is planned to improve the safety awareness of personnel. Future efforts will be made to communicate the process, and the risks associated with the process, to appropriate public sectors. Additional safety features (e.g., em ergency scrubber system, detection and alarm system, and personnel protection) were installed prior to the process hazard analysis performed on June 2, 1999. No additional safety measures will be added to the process. However, the existing crane/hoist will be properly secured and mounted, and safety posts installed near the process lines to prevent vehicle collision. Procedures for quality assurance regarding chlorine handling at the Wastewater Treatment Plant 1 Station and specific training on process safety management have been established. 4 |