Mayodan Water Treatment Plant - Executive Summary |
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The Town of Mayodan Water Treatment Plant is located at 500 East Roach Street, Mayodan, NC 27027. The Town of Mayodan Water Treatment Plant makes every effort to prevent accidental release of any hazardous chemical into the environment surrounding our facility. Any hazardous chemical used at the water plant is necessary for the safe treatment of drinking water and is maintained on the facility in the least amount possible. Additionally, all plant personnel are trained in the safe use of any hazardous chemical present. Still, we plan for the worst possible scenario and have an emergency response plan coordinated with the Rockingham County Local Emergency Planning Committee as well as with a specially trained chlorine emergency response team. The Town of Mayodan Water Treatment Plant produces drinking water for the Town of Mayodan, the Town of Stoneville, and the surrounding area. We draw our raw water from the Mayo River. In our treatment process of water, we use only one extrem ely hazardous substance, chlorine gas. We keep a maximum of 4000 pounds of chlorine gas on the site at any one time [2-ton cylinders]. Chlorine is a necessary ingredient in drinking water because it disinfects the water making it safe from pathogens. Due to the potential hazards from the accidental release of chlorine gas, the United States Environmental Protection Agency (EPA) has implemented Risk Management Program (RMP) regulations to prevent and minimize the impacts of any potential release into the environment. In planning for a potential chlorine release, we considered the worst-case release scenario. Although the risk for such a release is small, the impact upon the surrounding environment could be extremely serious. For this reason, it should be considered in emergency planning. We used a model [EPA's RMP*Comp ()] to calculate the potential toxic distance of release of chlorine gas. The worst possible situation we could imagine was the rupture of a ton cylinder of ch lorine. This assumed a 2000-pound release of chlorine at a rate of 200 pounds per minute for a 10-minute duration. The model revealed that the distance to endpoint toxicity would be 1.3 miles. This would include an estimated residential population of 3000 persons within the 1.3 mile radius from the Water Treatment Plant. A more likely alternate release scenario would be the rupture of a flexible, chlorine line attached to the ton cylinder. Again, using EPA's RMP*Comp() model, we assumed a release of 1500 pounds of chlorine at a rate of 150 pounds per minute for a duration of 10 minutes. The model for this scenario predicted a 0.20-mile distance to endpoint toxicity. The estimated population within this 0.20-mile radius would be 210 persons. To avoid either of these scenarios, the Mayodan Water Treatment Plant has implemented the Program 3 Prevention Program of the EPA Risk Management Program as regulated in 40 CFR 68.65 through 68.87. This involves gathering Process Safety In formation, doing a Process Hazard Analysis, developing and following Operating Procedures, Training of employees, ensuring Mechanical Integrity of process equipment, having a procedure for the Management Of Change, having a Prestartup Safety Review, doing Compliance Audits, having Incident Investigations, ensuring Employee Participation, issuing Hot Work Permits for the process area, and regulating the use of Contractors in the process area. Also a Management System for the whole program was developed and implemented according to 40 CFR 68.15. The Town of Mayodan Water Treatment Plant has not had an accidental chlorine release within the last five years. In the event of an accidental chlorine release, the Rockingham County LEPC will be notified to respond. The Mayodan Fire Department will respond immediately and secure the area along with the Mayodan Police Department. Additionally, Jones Chemical, Inc. will be contacted to respond with a Chlorine Emergency Response Team. The chl orine release would also be reported to Chemtrec. Plans are underway to eliminate the use of chlorine gas altogether in our treatment process. Within future budgets we hope to go to a liquid bleach form of disinfectant. |