Stone Dam Creek Wastewater Treatment Plant - Executive Summary |
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In this wastewater treatment plant facility (Stone Dam Creek Wastewater Treatment Plant) we handle chlorine and sulfur dioxide. which are considered hazardous by EPA, OSHA, etc. Chlorine is the only chemical that this facility handles enough of to include in the Risk Management Plan. The same properties that makes chlorine valuable as a water treatment chemical, also makes it neceddary to observe certain precautions in handling chlorine. Overall, the prevention of unnecessary human exposures, reducing the threat to our own personal health as well as our co-workers, and reducing the threat to nearby members of the community is the main goal of incorporating this risk management plan into our daily operations. It is our policy to adhere to all applicable federal and state rules and regulations. Safety depends upon the manner in which we handle and use chlorine combined with the safety devices inherent in the design of this facility, with the safe handling procedures that we utilize, along with the training of our personnel. The primary purpose of this facility is to treat the water supply by utilizing chemicals such as chlorine. Chlorine is received by individual one tone cylinders and stored until needed. Chlorine is fed into the water system by automatic vacuum operated feeders. The vacuum system will help prevent the continual operation of the chlorine feed after it reaches the wall mounted regulator. However, if there is a leak between the cylinder and the wall mounted regulator (feed line) the only way to shut off the system is to manaully shut off the chlorine valve at the cylinder. Access tot he site is restricted to authorized facility employees, authorized management personnel, and authorized contractors. The maximum amount of chloirne at this Stone Dam Creek Wastewater Treatment Plnat, Conway, AR is 8,000 pounds. Our employees conduct proper cylinder chnage-out procedures daily. They also review operating procedures and maintenance tasks daily or as when needed. The prevention program for this facility is a Level 2. Lock-out/Tag-out Procedures are used to help prevent an accidental release of chlorine. When maintenance is conducted on the chlorination system, the Plant Supervisor (Bill Fulmer), and the Water Manager (David Bradley) approve the proper installation of materials, and complete installation. Any change in maintenance procedure is reviewed and approved by Bill Fulmer and David Bradley. All opeators at this facility are knowledgeable in the proper start-up and shut-down procedures for the wastewater treatment operations. All guages, valves, fitings, etc. are checked every hour. Our emergency response (action) program was developed with the assistance of Environmental Data Services, Inc., the Conway Fire Department, and the Faulkner County LEPC. If a chlorine release occurs at the Stanley Russ Road location, the chlorine alarm will sound which will notify personnel at the facility of a release. Plant Super visor (Bill Fulmer) will get personnel organized for a emergency action and possible evacuation. On-duty personnel have SCBA equipment that they will use to enter the confined space (due to toxic atmosphere) and determine extent of release. They can perform an emergency action by atempting to shut off the chlorine cylinder by using the manaul valve. If the release cannot be controlled by the manual valve shut-down, then evacuation procedures will then be followed. A head count will be made of employees and David Bradley (Water Manager) wil be contacted, then the 911 call will be made to notify the Conway Fire Department, Faulkner County LEPC, and Conway Police Department of the release. Conway Fire Department will organize the Emergency Response activities, and will start evacuation of the affected population. The rrelease could be slowed by not starting the vent system in the chlorine room until notification to 911 system is made, and evacuation activities can begin. This will not prevent chlorine from releasing, but will allow for some time to respond. The worst case scenarion for this facility is a one ton cylinder failure, which would be a release of 2,000 pounds of chlorine into the atmosphere. Active mitigation has been considered for this scenario consisting of manual shut-offs and automatic vacuum feed chlorine system. Passive mitigation has also been considered for this release scenario, which would be a release into an enclosed space with little contact with outside air. It is assumed that the entire contents of the cylinder are released as vapor. The distance to endpoint of 0.087 mg/l for the worst case scenario is 3.5 miles. The area surrounding the facility is considered to be urban due to the thick trees and vegetation, as well as the hilly terrain. This worst case scenario would impact approximately 20,000 persons. An alternate release scenario was determined for the Stanley Russ Road location. The cylinder operate on a vacuum feed sys tem, so the amount of chloirne released at the Stanley Russ Road location would be less (approximately 500 pounds). This release of chloirne would result in a distance to endpoint of approximately 0.81 miles. This relatively short distance would impact approximately 1,300 persons surrounding the location (all populations were based on Landview Software). There have been no accidental releases of chlorine from this facility in the past five years. The automatic vacuum system helps to reduce the amount of chloirne released that could escape during operational periods. Operators of the chlorination system are requried to check instruments, cylinders, feed systems, etc. on a daily basis to aid in the prevention of accidental releases. Even though this is a Level 2 Prevention Program, Conway Corporation has chosen to utilizea Level 3 Process Safety Management prevention program to furthur emphasize their efforts in preventing accidental releases. This wastewater treatment facility co mplies with EPA's Accidental Release Prevention Rule, and with all applicable state/federal regulations. |