Big Goose Water Treatment Plant - Executive Summary |
|
The Big Goose Water Treatment plant located at 1350 Big Goose Road, Sheridan Wyoming is owned jointly by the Sheridan Area Water Supply Joint Powers Board and the City of Sheridan, Wyoming. The Big Goose Plant is administered, operated, and maintained, under contract, by the City of Sheridan. The Big Goose Water Plant is located approximately 13.5 miles west of Sheridan. It is a standard surface water plant utilizing coagulation, flocculation, sedimentation, and filtration. Chlorine, a regulated substance, is added to the final product for disinfection. Chlorine from one ton containers is used, with a maximum storage of 8,000 pounds. The chlorination system consists of two gas, vacuum operated, ton mounted chlorinators, one in service and the other on stand-by. The chlorinators will discontinue the flow of chlorine gas should the operating vacuum be lost. When the in service container is empty, a vacuum type automatic switchover module, will automaticly transfer to the stand-by conta iner to allow for continuous chlorination. Two rotameters control the rate of chlorine gas flow. The ejector supplies the vacuum needed for the system to operate and eject chlorine gas into the supply water, making a chlorine solution. Also, in the event of a chlorine release a one ton chlorine scrubber would switch on and prevent the release of chlorine from the building. For accidential release prevention, there is a fully operational and enforced Process Safety Management program, operating personnel perform daily inspection of chlorination equipment and the chlorine storage area, scheduled maintenance, in house and off site training. Inspection of chlorine containers prior to unloading and acceptance. A minimum of one drill is conducted annually with the Hazardous Material Response Team and coordinated with the Local Emergency Planing Committee. For emergency response, personnel will evacuate the plant; 911 Emergency Services will be notified by the release alarm system and will dispatch the Hazardous Material Response Team and Emergency Medical Services. Plant personnel will contact 911 to confirm alarm notification or give chlorine release notification. The Hazardous Material Response Team is in charge of and responsible for all activities involving a chlorine release. Public notification of a chlorine release will be given at the discretion of the Incident Commander. The worst-case scenario, while possible is not considered probable, is the total release of a 1 ton container (2,000 pounds) of chlorine at 110 pounds per minute for a 10 minute duration; the end-point distance would be 2.2 miles. The alternative release scenario is the release of 512 pounds of chlorine at 4.25 pounds per minute for a 120 minute duration; the end-point would be 0.10 miles. The Big Goose Water Treatment Plant has not had a chlorine release and has no accident history. |