Highway 211 Water Treatment Plant - Executive Summary |
|
1.0 EXECUTIVE SUMMARY 1.1 Accidental Release Prevention and Emergency Response Policies The Highway 211 Water Treatment Plant utilizes chlorine as part of the water purification process. Chlorine is considered a hazardous substances by the EPA. This makes it necessary to observe safety precautions in handling chlorine in order to prevent unnecessary human exposure, to reduce the risk to on-site employees, and to reduce the risk to nearby members of the community. The Highway 211 Water Treatment Plant has coordinated emergency response measures with the Brunswick County Emergency Management Services (BCEMS). Representatives of BCEMS conduct periodic visits to the site, and have conducted SCBA training with facility personnel. In the event of an accidental release of chlorine or ammonia, facility personnel have been instructed to evacuate the facility and notify BCEMS of the nature of the emergency. BCEMS will notify appropriate local emergency response resources, and will respon d to the release and attempt to bring the release under control. BCEMS will also notify the surrounding communities if evacuations are necessary and will notify additional emergency response agencies, as needed. 1.2 Stationary Source and Regulated Substances Handled The only regulated substances presently in use at the Highway 211 Water Treatment Plant is chlorine. Chlorine is used in the chlorine injection system for water purification. Chlorine is received at the facility by truck, and is stored in four one-ton steel cylinders. The cylinders are located outdoors, to the south of the control room. Access to the facility is controlled by a chain link fence and a gate, which is kept locked when not in use. The maximum amount of chlorine that can be stored at the facility is 8,000 pounds. During normal operating conditions, two chlorine cylinders are hooked up to the chlorine injection system, and two unused chlorine cylinders are maintained as spares. 1.3 Worst-Case Release Sc enario The worst-case release scenario for chlorine assumes failure of the valve on one of the chlorine cylinders. The failure results in the release of the entire contents of one cylinder (2,000 pounds) over a ten-minute period. The effective release rate for this scenario is 200 lb/minute. The distance to the toxic endpoint of 0.0087 mg/L for this scenario is 2.80 miles. 1.4 Alternate Release Scenario The alternate release scenario for chlorine assumes failure of the piping, valve, or connection leading from one of the chlorine cylinders to the chlorine header line. The failure results in the release of the entire contents of one chlorine cylinder (2,000 pounds) over a sixty-minute period. The effective release rate for this scenario is 33.3 lb/minute. The distance to the toxic endpoint of 0.0087 mg/L for this scenario is 0.54 miles. 1.5 Five-Year Accident History The Highway 211 Water Treatment Plant has not had any incidents or accidental releases involving the chlorine injection system since it was installed in February, 1976. 1.6 Emergency Response Program The Highway 211 Water Treatment Plant does not currently maintain a written Emergency Action Program (EAP). In the event of a chlorine release, the Northwest Water Treatment Plant has coordinated emergency response measures with the Brunswick County Emergency Management Services (BCEMS). 1.7 Planned Changes to Improve Safety The Highway 211 Water Treatment Plant does not currently have any plans to upgrade or modify the chlorination system. The facility does plan to upgrade the system in order to comply with future changes to ASTM or ASME standards, or other standards pertaining to chlorine handling and storage. |