Rathbun Regional Water Association, Inc. - Executive Summary |
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EXECUTIVE SUMMARY 1. Accidental release prevention and emergency response policies: In this water treatment facility, we handle chlorine that is considered hazardous by the U.S. Environmental Protection Agency (EPA). The same properties that make chlorine valuable as a disinfectant also require observance to certain safety precautions in handling chlorine to prevent unnecessary human exposure, to reduce the threat to our own personal health as well as our co-workers, and to reduce the threat to nearby members of the community. Our policy entails the intent to adhere to all applicable Federal and state rules and regulations. Safety depends upon the manner in which we handle chlorine combined with the safety devices inherent in the design of this facility. It is also dependent on safe handling procedures and the training of our personnel. Much of our emergency response program is based upon the procedures established in the Chlorinators Incorporated Operation and Maintenance Manual s prepared for this facility and chlorine safety information from the Chlorine Institute. The emergency response plan includes procedures for notification of the local fire authority and notification of any potentially affected neighbors. 2. The stationary source and regulated substances handled. 7 The primary purpose of the Rathbun Regional Water Association, Inc. (RRWA) Water Treatment Plant is to clean and disinfect water to be used by rural water customers in the counties of Appanoose, Clarke, Davis, Decatur, Lucas, Monroe, Van Buren, Wayne, small portions of Marion, Wappelo, and Warren counties in the State of Iowa and three rural water districts in the State of Missouri for potable purposes. Chlorine is shipped by truck to the plant in 2,000-pound cylinders (one ton). The chlorine cylinders are offloaded from the truck into the chlorine storage room with a hoist crane. The chlorine storage and feed rooms are two separate rooms adjoining the rest of the water plant. The chlo rine storage and feed rooms adjoin the rest of the treatment plant building. Personnel access in and out of the chlorine storage and feed rooms is from the outside the treatment plant building. 7 The regulated substance handled at this facility is chlorine. The maximum amount of Chlorine that can be stored at this plant is 6,000 pounds. 3. The worst-case release scenario(s) and the alternative release scenario(s), including administrative controls and mitigation measures to limit the distances for each reported scenario. 7 Worst-Case Scenario: The worst-case scenario has been defined as a 2,000-pound cylinder rupturing outside the chlorine storage room while unloading from the truck due to corrosion, impact, or construction defects. 7 The distance to the toxic endpoint of 0.0087 mg/l (8.7 mg/cubic meter) for the worst-case scenario is 2.6 miles. 7 Alternative Scenario: The alternative-case scenario has been defined as a release from process piping or valves inside the chlorine storage room. The maximum total release was 318 pounds. The maximum average sustained release rate was established at 10.5 pounds per minute over a 60-minute duration. 7 In average weather conditions, the distance to the toxic endpoint of 0.0087 mg/l (8.7 mg/cubic meter) for the alternative-case scenario is 0.48 miles. 7 Comparing alternate source assumptions, the model predicts that the release rate in the alternative case scenario will be limited by the flow through each of the 5/16-inch valve openings at the chlorine containers rather than flow through the piping. 4. The general accidental release prevention program and the specific prevention steps. This water treatment facility has worked to comply with EPA's Accidental Release Prevention Rule and with state codes and regulations. This facility was designed and constructed in 1977 and contains separate chlorine storage and feed rooms. The ventilation system in the chlorine storage room maintains both rooms under negative pressure preventing released chlorine from migrating directly to other interior portions of the water treatment plant. Chlorine gas detector will be installed in the chlorine storage room. The detector detects chlorine release as low as 1 parts per million and sounds an alarm in the control room and appropriate response measures can be initiated. 5. Five-year accident history. We have not had an accidental release of chlorine from the covered process that resulted in deaths, injuries, or significant property damage on site, or known offsite deaths, injuries, evacuations, sheltering in place, property damage, or environmental damage. 6. The emergency response program. The facilities emergency response program is based upon responding to upset or malfunction conditions as described in the Operation and Maintenance (O & M) Manual prepared for Rathbun Regional Water Association Inc. Water Plant. The Mystic Fire Department will be called (dial 911 or 515-437-7100) in the event of a ch lorine release. We have discussed this program with the Mystic Fire Department and the Appanoose County Local Emergency Planning Coordinator. 7. Planned changes to improve safety. Currently, improvements are underway to the chlorine storage and feed system to improve safety, reliability of operation, and redundancy. The new feed mechanism will be an all-vacuum feed system up to the point of application. Planned process improvements include new 1-ton container digital scales, vacuum regulators, automatic switchover unit, automatic flow proportioning gas feed valves, automatic solenoid valves, and a chlorine gas detector. The new system incorporates an early warning chlorine gas detector in the chlorine storage room and an alarm system in the central control room. The detector has been set to detect chlorine levels as low as 1 parts per million (ppm) triggering audible alarms in the control room. The facility is in operation 24-hours a day and continuously manned; consequently, some one is always around to initiate emergency response procedures should the alarm sound. |