WASTEWATER TREATMENT PLANT - Executive Summary |
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The Price River Water Improvement District Wastewater Treatment Plant (WWTP) accidental release prevention policy involves a limited number of individuals and only two controlled processes wherein small quanitities of regulated substances are involved. The location of this facility is separated by expansive open space which serves as a "buffer zone" in the event of an accidental release. The primary purpose of the WWTP is to treat domestic and commercial sewage collected throughout the area to a level where the water may be re-introduced to the environment. Also, the solids removed from the waste stream are converted into a usable product for soil enhancement. Chlorine is used in this water treatment process as a disinfection agent in the final effluent. Sulfur Dioxide is introduced into the chlorinated water as a de-chlorination agent, or to remove the chlorine so as not to be toxic to the environment as it is discharged into the receiving stream. The WWTP will inventory chlorin e between the amounts of 1,000 lbs to 5,000 lbs with no more than 2,000 lbs being placed in service at one time. This chemical is delivered primarily from Thatcher Chemical of Salt Lake City, Utah in 2,000 lb containers. These containers are clearly marked by color and label. The container is of heavy wall type construction and all joints are welded. Cylinders are clearly numbered and weighed for tare weight. Fusable plugs are also installed to prevent bursting in the event of overheating of the cylinders. Additionally, the WWTP will inventory Sulfur Dioxide between the amounts of 500 lbs to 2,500 lbs, with no more that 2,000 lbs being placed in service at one time. This chemical is delivered primarily from Thatcher Chemical of Salt Lake City, Utah in 2,000 lb containers. These containers are clearly marked by color and label. The container is of heavy wall type construction and all joints are welded. Cylinders are clearly numbered and weighed for tare weight. Fusable plugs are also installed to prevent bursting in the event of overheating of the cylinders. The WWTP has adopted several operational/management procedures to minimize the possibilities of accidental release and to maximize the control of and response to an event of accidental release. These are as follows: 1. Chemical cylinders are never to be connected to draw liquid chemical as this may cause over pressurization of a cylinder or chemical feed system. 2. Chemical cylinders are only to be connected to the gas controlls which allow separation of cylinders while offering alternate cylinder use. 3. Chemical cylinders are to be moved only with the equipment specifically designed and designated for this purpose. 4. When the facility is receiving a supply of chemical containers, no cylinders are to be in the process of connection or disconnection. 5. A minimum of two (2) operators shall be actively involved in the receiving and/or exchanging of chemical cylinders. 6. A minimum of two (2) operators shall be actively involved in the connection and/or disconnection of chemical cylinders. 7. Self Contained Breathing Apparatus will be maintained in ready condition at all times. In the event that a chemical release prevents access to the primary storage area of these SCBA's, two additional sites will be established in progressively more distant locations to ensure that access is available. All SCBA's will be maintained and tested in accordance with manufactures recommendation. 8. Chlorination and Sulfonation equipment shall be inspected daily. 9. In the event of an alarm or accidental release, no less than two (2) operators will respond to the emergency. 10. Upon confirmation of an alarm and establishment of the nature of the emergency, Carbon County Dispatch and the LEPC will be notified. Emergency respons e personnel will be notified. In establishing a "Worst Case Senario", the WWTP has followed the guidelines set forth by the U.S. Environmental Protection Agency's "Off-site Consequence Analysis" wherein it is determined that 2,000 lbs would be released within a 10 minute time limit in a gaseous form. With the deletion of any mitigation measures; it is determined that with a wind speed of 1.5 m/sec., the affected area of levels above the toxic end point of 0.0087 ppm would measure 1 mile in any direction. This would effect approximately 100 residents within this area, but would not include any schools, hospitals, or environmentally sensitive areas. The Price River Water Improvement District Wastwater Treatment Plant has been using chlorine for disinfection since 1971 and sulfur dioxide since 1986. Throughout this entire time, not one reportable accidental release has occured, no personnel have been adversely effected, and no off-site effects have been measured or reported. There fore, the WWTP will not be making any attempts to modify the training of its personnel, its safety equipment, or policies and procedures concerning these chemicals. |