City of Hendersonville Water Treatment Plant - Executive Summary |
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City of Hendersonville Risk Management Plan (RMP) Water Treatment Plant ACCIDENTAL RELEASE PREVENTION AND EMERGENCY RESPONSE POLICIES The policy for the prevention of accidental release is to ensure that all WTP personnel are trained to follow well defined safety procedures while working with chlorine cylinders and piping. The policy for emergency response is to ensure that all WTP personnel are aware of the procedures for notifying emergency response organizations, such as local fire departments and the Local Emergency Planning Committee. FACILITY DESCRIPTION AND REGULATED SUBSTANCES HANDLED The Hendersonville Water Treatment Plant treats up to 12 MGD of raw water from the Mills River. Part of the treatment process involves the injection of chlorine, a very common and effective method of controlling coliform and other harmful bacteria. Chlorine is stored in a room of the treatment plant in 2000 pound pressurized cylinders, and supplied by piping to the water to be treated. WORST CASE RELEASE SCENARIO A complete loss of chlorine from a 2000 lb storage tank would occur within the chlorine storage room. Dispersion would be mitigated by the room, but according to the model the chlorine would migrate somewhere within a 2.2 mile radius circle around the plant. Public and enviornmental receptors within the circle that could be adversly affected by the release include residences, schools, a National Forest and a small shopping center. The population within the circle is estimated to be 1500 people. ALTERNATIVE RELEASE SCENARIO A loss of 1100 pounds of chlorine would occur within the chlorine storage room as a result of a relief valve failure. Dispersion would be mitigated by the room, but according to the model the chlorine would migrate somewhere within a 0.4 mile radius circle around the plant. Public and environmental receptors within the circle that could be adversly affected by the release include residences. The population within the circle is es timated to be 50 people. GENERAL ACCIDENTAL RELEASE PREVENTION PROGRAM AND CHEMICAL SPECIFIC PREVENTION STEPS Procedures for changing the chlorine cylinders are posted and require two operators to be present. Chlorine regulators are rebuilt and tested by the manufacturer each year. A spare regulator is on hand at all times. Chlorine regulators, rotameters, regulators and tubing are inspected at least once a year and replaced as necessary. FIVE YEAR ACCIDENT HISTORY There have been no reportable accidents at the Hendersonville Water Treatment Plant in the previous five years. EMERGENCY RESPONSE PROGRAM The WTP is manned on a continuous basis. In the event of a release of chlorine gas in the chlorine storage room, both audible and visual alarms would sound. The operator on duty would immediately dial 911 to alert local fire departments, would call the County Fire Marshall who is in charge of the Local Emergency Planning Committed (LEPC) and would contact the Operator in Respo nsible Charge (ORC) or backup ORC. WTP operators have received training in hazardous materials spill response and chlorine safety and repair work. Both the local fire departments and the LEPC have inspected the WTP chlorine storage room. Depending on the seriousnous of the leak, one or more of the following actions would be taken: 1. WTP operators would repair the leak themselves 2. A trained leak repair crew would be called in from the chlorine vendor. Response time for this would be approximately 1 hour or less. 3. The surrounding area would be evacuated. This would be coordinated by the LEPC, who would also handle public notification utilizing emergency vehicles with loudspeakers. Drills for this type of emergency are conducted at the WTP on a regular basis and involve hands-on practice with SCBA's, hazmat chemical suits, and chlorine leak repair kits. PLANNED CHANGES TO IMPROVE SAFETY The safety record at the Hendersonville Water Treatment Plant has been excellent. In order to maintain this record, WTP personnnel will be trained on a regular basis including annual chlorine safety seminars,water plant operator certification courses, and hazardous materials awareness courses. In addition, all WTP personnel are required to perform an annual review of the Process Safety Management Plan and all process safety information. |