Visalia Wastewater Treatment Plant - Executive Summary |
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FEDERALLY MANDATED RMP SUBMISSION EXECUTIVE SUMMARY 1. Accidental Release Prevention and Emergency Response Policies This City of Visalia Wastewater Treatment Facility, located at 7579 Avenue 288, Visalia California, handles chlorine, which is considered a hazardous material that is a regulated substance and is considered in the Risk Management Plan (RMP). The properties of chlorine make it necessary to observe safety precautions in handling to prevent human exposure, and to reduce the threat to the facility's workers and nearby members of the community. It is the facility's policy to adhere to all applicable Federal and State of California rules and regulations. Safety depends upon the safe procedures used to handle chlorine; the safety devices and systems designed and constructed into the facility; and the training of the pertinent personnel. 2. Stationary Source and Regulated Substances Handled The City of Visalia WWTP uses chlorine gas to disinfect wastewater. The chlorine is injected into the waste water in the wet well area of the headworks to control order and reduce metal and concrete corrosion in the plant units. The overall system provides for the addition of chlorine in the distribution structure "A" to the secondary weirs and in the chlorine contact basins. Chlorine is delivered by a commercial chlorine supplier in one-ton containers for use at the WWTP. All the one-ton containers that are connected into the manifold system are placed in the chlorine building on a metal storage rack. A total of 14 one-ton containers are stored (28,000 lbs). Delivery of the one-ton containers is during normal working hours. The container storage and handling is conducted pursuant to per Sections 2.6, 2.7, and 2.8 of the Chlorine Institute's Chlorine Manual. The plant operator is required to study the "Disinfection and Chlorination" course from the California Water Pollution Control Association Operator's Short School or similar material. This treat ment facility operates twenty-four hour per day, seven days per week. The chlorine liquid is supplied to the evaporator from the one-ton cylinders where it is converted to gas and enters the chlorinator. The chlorine gas is withdrawn from the one-ton containers by vacuum. This vacuum opens the vacuum regulator diaphragm and withdraws the chlorine gas from the one-ton containers at a controlled feed rate set by the operators with the use of the rotometer at the chlorinator unit. The chlorine gas is controlled, metered, and then piped to the point of application. The gas is injected into the feed water line, where it becomes a chlorine/ water solution and applied as needed. The chlorine building is equipped with a leak detector alarm system. The receipt, storage, and handling of the subject substance are considered as part of one complete process. 3a. Worst Case Release Scenario The one ton (2,000 pounds) chlorine container is the largest vessel in the chlorine system located a t the Wastewater Treatment Facility. The Worst Case release scenario to be modeled for the one ton chlorine container assumes that the full 2,000 pounds of chlorine is released over a ten minute period resulting in a release rate of 200 pounds per minute. The distance to the endpoint of 0.0087 mg/l for the Worst Case scenario is 1.3 miles. This chlorine release will extend beyond the boundaries of the stationary source. 3b. Alternative Release Scenario The Alternative Release scenario for chlorine for the one ton container located at the Wastewater Treatment Facility assumes a release from valve packing, resulting in an estimated release of no more than 2 pounds per hour. The period of release is taken to be one hour in duration, resulting in a total release quantity of 2 pounds for each regulated substance. The distance to the endpoint of 0.0087 mg/l for the Alternative Release scenario is 0.1 mile. This chlorine release will extend beyond the boundaries of the stationary sou rce. 3c. Administrative Controls Administrative controls to limit the distances for each reported scenario exists to restrict to a minimum the amount of chlorine released, if a release were to occur, and preferably to not have a release occur. This administrative control is inherent in the operational procedures for the chlorine and the training provided to the chlorine operators. 3d. Mitigation Measures Mitigation measures to limit the distances for each reported scenario exists to restrict to a minimum the amount of chlorine and aqua ammonia released, if a release were to occur, and preferably to not have a release occur. The mitigation measures are based upon the design, inspection, testing, and maintenance of the chlorine system and its related equipment and components. 4. General Accidental Release Prevention Program and Chemical Specific Prevention Steps The facility complies with all applicable federal and state codes and regulations. There are safety meetings and saf ety training. The Process Safety Management (PSM) program implemented at the facility for the chlorine related activities and equipment represents one of the facility's main active commitments to an accidental release prevention program. 5. Five Year Accident History There have been no incidents involving the release of chlorine within the past five years at the facility. 6. Emergency Response Program The Emergency Response Program is based on alerting personnel at the facility of the need to evacuate the facility and await the arrival of responders from the City of Visalia Fire Department at the evacuation assembly location if a release occurs that causes the evacuation to be initiated. The Tulare County- Environmental Health Department can incorporate this response into the County Area Plan for the Local Emergency Planning Commission. 7. Planned Changes to Improve Safety There are commitments made under the Process Hazard Analysis element of the Process Safety Management (PSM ) that are being implemented at this time for the next year. Current applicable codes and regulations are reviewed as part of the PSM to determine if other commitments need to be made to achieve increased operational safety for the regulated chlorine system. These commitments will be prevention and mitigation measures for accidental releases of the regulated substances. |