Poway Chloramination Facility - Executive Summary |
RISK MANAGEMENT PLAN RAMONA MUNICIPAL WATER DISTRICT POWAY CHLORAMINATION FACILITY 15201 GREEN VALLEY TRUCK TRAIL POWAY, CA 92064 SECTION 1: EXECUTIVE SUMMARY This risk management plan addresses the risk management program for Ramona Municipal Water District Poway Chloramination Facility. This plan applies to the process conducted to store chlorine gas cylinders and to chlorinate the potable water supplies and distribution systems 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. Ramona Municipal Water District's Poway Chloramination Facility 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., San Diego County HAZMA T Team, and Ramona Fire Department/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). Ramona Municipal Water 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 mitigat ion specialists. The program implements the elements of the 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 Poway Chloramination Facility. The Ramona Municipal Water District was established on August 15, 1956, under the Municipal Water District Act of 1911. The District is governed by a five-member Board of Directors elected to staggered four-year terms of office, each representing a geographical division in which the member resides. The board elects its officers at its first meeting in January of each odd-numbered year. Regular meetings of the board are held bimonthly. The District utilizes outside consultants on a continuous, as needed basis for operational and environmental concerns. The Ramona Municipal Water District encompasses approximately acres 48,000 acres (75 s quare miles), located near the geographic center of San Diego County in the Santa Maria and San Vicente Valleys. The District has an estimated population of 32,000 residents (see Figure 1-1). The District provides water, fire protection, sewer, park and recreation services to the community of Ramona. The District serves approximately 8,420 water connections on a regular basis, with some residents having their own private water supply. The District's boundaries are adjoined by the City of Poway to the west, the City of San Diego to the northwest, the Cleveland National Forest to the northeast, the community of Lakeside to the south, and the Barona Indian Reservation to the southeast (see Figure 1-2). Approximately 6,000 acre-feet of potable water and 3,700 acre-feet of non-potable water are delivered to District customers each year. Water is supplied for both residential and agricultural use from three sources: a District-owned well field, Sutherland Reservoir, and the San Dieg o County Water Authority. The water drawn from Sutherland Reservoir is treated at the District's water treatment plant, and the water from the water authority's aqueduct is treated at Lake Skinner. The dual water system permits delivery of untreated water for approximately 6,200 acres of agricultural lands. The area is unique in many ways due to its varying elevations and high rate of irrigation. Average rainfall per year is approximately eighteen (18) inches. The District headquarters is located on 105 Earlham Street. One-ton chlorine gas cylinders are routinely delivered directly to the Poway Chloramination Facility (located at 15201 Green Valley Truck Trail, Poway) by an offsite chemical supplier, which varies based on economic value and costs. The Poway Chloramination Facility has three (3) one-ton cylinders that exceeds the Federal and State thresholds. Other facilities containing chlorine gas cylinders include the Bargar Water Treatment Plant and the Wellfields Injection Site. The Bargar Water Treatment Plant has six (6) one-ton cylinders on-site. A separate Risk Management Plan will be prepared for the Bargar Water Treatment Plant to address the Federal requirements. The Wellfields Injection Site has twelve (12) 150-pound cylinders on-site that exceed the State threshold quantity. A separate Risk Management Plan will be prepared to address this site, as agreed upon by the San Diego County Department of Environmental Health, Hazardous Materials Division. Figure 1-4 shows the Poway Chloramination Facility layout. The empty cylinders are stored temporarily at the chlorination 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 in 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 three (3) full one-ton cylinders are stored onsite at the Poway Chloramination Facility. The chlorine gas cylinders are stored in a fully-enclosed concrete structure. Usage rates vary from one month to several months, up to one year for each injection site. Turn-around time never exceeds one year for each injection site. 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 full 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 Manag ement 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 model 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 the concrete-block building 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 pl ace 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. A visual alarm system is installed at the site and is 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 personnel to ensure that safety equipment maintenance and repair are properly completed in a timely manner. 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 c ylinders. Additional training on the Ramona Municipal Water 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 will be added to the process, based on the recent process hazard analysis, and will be implemented as the budget planning allows. Procedures for quality assurance regarding chlorine handling at the Poway Chloramination Facility and specific training on process safety management have been established. 4 |