Truckee Meadows Water Reclamation Facility - Executive Summary |
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The City of Sparks operates a 40 million gallon a day wastewater treatment facility which serves the City of Sparks and Reno. The Truckee Meadows Water Reclamation Facility as it is known stores two 17 ton chlorine tankers on site used for the disinfection of treated wastewater which is released into Steamboat Creek which flows into the Truckee River. Chlorine is drawn from the tanker as a liquid, the liquid flows to a evaparator which converts the liquid to gas. This gas passes through a pressure reducing valve which converts the pressure gas to atmospheric pressure. V-notch vaccum chlorinators take this atmospheric pressure gas and feeds it to different parts of the plant for proper wastewater disinfection. Chlorine tankers are owned by our chemical supplier and are delivered every 10 days. When a tanker is emptied we switch to the full tanker and reorder chlorine. Chlorine is delivered only after 5 pm to minimize the amount of employees on site in case of any chlorine emergen cy. There is a minimum of 5 operators on duty during delivery and 2 of these operators assist with the delivery. Standard Operating Procedures are written for all of these processes and updated on a routine basis. The chlorine tankers are stored in an enclosed building which is next to the chlorine feed room and these rooms are served by a caustic scrubber system. The scrubber system is designed to handle the full release of one 17 ton tanker in less than 9 hours such that the remaining chlorine concentration in the contaminated area is less than 1 part per million. The scrubber is designed to work either in automatic or hand mode. Chlorine sensors located in the chlorine buildings continually read the atmosphere and if they detect 1ppm they automatically close the auto shut down valves located on the tank domes. If the sensors detect 3ppm they automatically turn the scrubber system on. Facility Management regards chlorine as its highest hazard and is committed to prevent the accidental release of chlorine. Recently the facility hired a full time Safety Coordinator to oversee facility safety including chlorine. Part of his duties is forming a chlorine incidental release response team. This team will take part in responding to small incidental releases of chlorine which is under their training guidelines. Both the worst case and alternative release scenario were completed with RMP Comp. Our worst case of 17 tons of chlorine being released within a 10 minute time frame is highly unlikely. The tankers have built in excess flow valves and our facility has automatic shut down valves which close when the leak detectors sense 1 ppm of chlorine in the atmosphere. The tankers are serviced and maintained according to Department of Transportation standards and their complete failure is highly unlikely. Our alternative release is based on a hole in the liquid line of chlorine. This is the type of release which we need to be prepared for the most, although the type of releases that were experianced in the past were of a much smaller nature. We have had mostly packing nut leaks, leak through a pressure gauge and such. These leaks are confined to the area and have been controlled by our scrubber system, auto shut down valves and operators quick reaction. The facility falls under the OSHA PSM regulations and worked with AcuTech Consultants on the chlorine and scrubber PHA. On a yearly basis an outside contractor comes in and performs the annual preventative maintenance on the chlorination system. At this time the faciity maintenance staff reviews this work and participates in training with the contractor. All of the chlorine and scrubber systems work with redundit systems, meaning if a piece of equipment fails we have backup equipment available. The facility has had seven accidental releases within the last 5 years causing no offsite consequensces or injuries to facility staff. These releases were never larger than 1 pound of chlori ne and the systems which were described earlier worked to there specifications. The facility emergency response plan is currently under review and will be incorparating some changes for the better of safety in the very near future. Currently employees are only to respond to chlorine leak alarms if they are in the area when the alarm acitvates and know what the situation is. Our current training needs to be updated, our respiratory protection guidelines need to be up to date and our incidental release team organized. We are working with our local fire departments and OSHA consultation on these issues and we have a clear picture of our responsibilities with chlorine in regards to our employees and the public and are working within our guidelines. We have had drills with our local fire departments within the last year. As stated before regarding the hiring of a full time Safety Coordinator, this person was hired to coordinate all of these things listed. His job list includes respir atory proctection, Process Safety Management, incidental release team, evacuation drills, coordination with our local responders, LEPC representative, coordianate purchasing of new leak sensors and controls, purchasing and training of proper PPE and overall facility and employee safety. We will be purchasing new advanced fixed chlorine sensors which will improve our ability to monitor the chlorine rooms. We have purchased hand held chlorine monitors to be used by employees when entering any area suspected of chlorine vapors. Employees will be participating in more and updated safety training. We realize that employee safety training is an ongoing process and are committed to protecting our human and natural resources. |