Ray L. Sherard Water Treatment Plant - Executive Summary |
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The Cheyenne Board of Public Utilities has an accidental release prevention program that utilizes technologies, comprehensive training, articulate procedures, state of the art leak detection equipment, and management practices. This emergency reponse policy and response plan is written specifically for the Ray L. Sherard Water Treatment Plant, utilizing all emergency response resources available in community. The Ray L. Sherard Water Treatment Plant is a surface water treatment plant that supplies potable water for the city of Cheyenne, Wyoming. The plant is located west of Cheyenne and is a direct filtration plant. The chlorine room of the plant contains ten one ton containers, three vacuum chlorinators, a chlorine leak detector, and three vent fans. This equipment is used for safe disinfection of treated water before being sent to the population of Cheyenne. The plant is normally manned 24 hours a day 7 days a week except for a shutdown period in the winter months for maintenance. The offsite consequence analysis includes two chlorine release scenarios, identified as "worst case scenario" and " alternate scenario." The worst case scenario is defined by EPA as "the owner or operator shall assume that the maximum quantity in the largest vessel is released as a gas over 10 minutes" due to an unspecified failure. The alternate scenario is defined as "more likely to occur than the worst case scenario". Atmospheric dispersion modelling using RMP Comp has been done to determine the distance traveled by the chlorine gas until it reaches it's toxic endpoint selected by EPA of 0.0087mg/L. The worst case scenario toxic endpoint reached a radius of 2.2 miles of point of release. The population inside the 2.2 mile radius is approximately 48 people according to GIS information and 1990 census data. The alternate scenario toxic endpoint reached a .1 mile radius from point of release. There is no residential population inside the .1 mile r adius. The general accidental release prevention program and chlorine specific prevention steps have been outlined the in OSHA PSM rule. There is close attention paid to mechanical integrity or preventive maintenance of equipment, operating procedures, management of change, and startup procedures after a change or a shutdown. All aspects of PSM are trained on at least annually with evaluation done by demonstration and observation. All procedures were written with the participation of the operators. A state of the art leak detection system is in place to notify personnel of a chlorine leak with a plant-wide evacuation alarm if the leak reaches 10 ppm in the chlorine room. All contractors and frequent plant visitors are trained on thier responsibilities during an emergency. There is one incident to report in the last five years. On July 1,1994 a small amount of chlorine was leaked during a chlorine manifold connection. No onsite or offsite injuries were incurred but a construction project onsite was evacuated to a safe distance. No enviromental damage was done. Fire District#1, Fire District #2, F.E. Warren AFB HazMat Team responded, a cap and gasket from the B Kit was placed over a valve and tank was shipped back to the vendor. No measureable amount of chlorine was released. This is the incident this facility has had in the last five years. The facility has an emergency response plan that has been coordinated the the local emergency responders, Fire District#1 Fire District#2 and F .E. Warren Air Force Base HazMat Team. In case of an emergency an operator is to notify 911 where upon they will notify the emergency responders. In 1997 a Process Hazard Analysis was conducted and through this procedure several changes were identified and completed to improve safety of operation. The impletentation of OSHA PSM and EPA RMP has lead the Sherard operators and management to become more safety conscience and to be safety proactive inst ead of reactive. |