Great Falls Wastewater Treatment Plant - Executive Summary |
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EXECUTIVE SUMMARY OUTLINE THE ACCIDENTAL RELEASE PREVENTION AND EMERGENCY RESPONSE POLICIES AT THE FACILITY? The USFilter Operating Services approach to chemical safety at the Great Falls plant has always been first and foremost to be in compliance with all applicable laws and regulations, but being in compliance does not ensure that accidents will not occur. We have stressed this fact repeatedly to the employees of this facilility. They have been involved extensively in writing and reviewing all plant specific policies relating to chemical safety. These policies are written to provide the utmost safety for plant personnel. Employees are instructed from the point of orientation that these policies are to be followed implicitly and any deviations or exceptions to these policies are not allowed. Training on chemical processes and SOP's is completed as required by OSHA and USFilter Corporate and stands to reinforce the importance of safe chemical handling. At the senior management level, the USFilter Corporation Safety and Environmental Compliance Mission is as follows: "USFilter will not compromise accident and injury prevention, or environmental protection compliance for profit or production". Its guiding principles are: - An uncompromising commitment to safety, environment and regulatory compliance from management and each employee is the key to achieving our mission and goal. - All employees have the right - and responsibility - to immediately halt and report unsafe or non-compliant equipment, acts, or practices. Management support of this policy is total and absolute. - USFilter strives to keep all employees aware of required safety, health and environmental procedures and provides the resources for each employee to ensure his/her own safety. - We strive for continuous improvement in all aspects of our safety and environmental compliance program - training, implementation and motivation. - Everyone is responsible for their own safety - and for the safety of those around them. - A measure of performance and commitment to safety standards will be an integral part of every employee's job and performance evaluation. - We will strive to meet or exceed all government regulations that affect our facilities. At the local level, management commitment to safety and health has played an important role in the success of the program. Countless hours continue to be allotted to safety for meetings, training, tailgate sessions, safety inspections, correction of hazards, policy review and updating, in addition to the time it takes to administer the program itself. USFilter managers at the plant not only allot the time necessary for a successful program but also participate in the program as well. All safety meetings are attended by plant management staff and are chaired by a supervisor. Managers monitor the activity of the committee outside the meetings as well. USFilter requires and pays for all of its employees to complete a full physical every two years and respirometry test every year. In addition, Hepatitis B vaccinations were offered and all potentially affected employees took advantage of the program. USFilter provides several incentives to its employees for working safely. For each year of no lost time accidents a safety dinner is provided and a monetary bonus is provided as well. At USFilter Great Falls, since 1977, there have been fifteen awards for working a year without a lost time accident and employees at one point went almost 7 years without an LTA. THE FACILITY The Great Falls Wastewater Treatment Plant is a Secondary Activated Sludge Treatment Facility, treating primarily domestic waste. The plant is rated at 21 million gallons per day but treats an average of 9.5 MGD of wastewater. Chlorine, the only regulated substance in the facility, is used to disinfect the final effluent during the months April thru October. By permit, we are not required to chlorinate the other five months of the year. We currently use on average about 200 lbs of gaseous chlorine per day when chlorinating. At this rate, addition of new cylinders from the storage dock to the scale/manifold is done only about once a month for the seven months we chlorinate. The maximum amount of chlorine that we can have in the facility is 18,000 lbs.; 6000 lbs on the scale and 12,000 lbs on the loading/storage dock. The actual amount in the facility on a day to day basis is usually < 10,000 as our supplier attempts to limit total cylinders (empty or full) in the plant to five. Chlorine can also be used in the process to control filamentous bacterial growth in the aeration basins. These bacteria inhibit the settling characteristics of the sludge, which in turn can cause solids washout to the effluent. This method of control is an option but is used infrequently. WORST-CASE SCENARIO The chlorine at the Great Falls facility is in 1-Ton containers, thus the worst case scenario involves the release o f 2000lbs of chlorine in 10 minutes or 200 lb/min. The failure occurs on the loading dock of the chlorine building which is outside. The facility is in an urban setting and using table 4-3 with an F stability and a 1.5 meters per second wind, the distance to the toxic endpoint is 1.3 miles. ALTERNATIVE RELEASE SCENARIO The present scale/manifold system allows three cylinders to be connected at one time. The pigtail hookups are each equipped with automatic switchover valves that allow a cylinder to come on line as another cylinder runs out of chlorine and the pressure drops to less than 15 PSI. The normal set-up has one cylinder on line, one in the standby mode and one in the off position. When the on line cylinder runs out, the standby comes on line. The operator then places the off line cylinder switchover valve to the standby position. The empty cylinder is removed from the scale and a full cylinder is moved from the storage dock to the scale and connected to the manifo ld. This becomes the cylinder in the off position. The alternative release scenario at the Great Falls Wastewater Treatment Plant occurs as the operators are moving a full cylinder from the loading dock to the scale/manifold room. As the cylinder is being moved over top of the on-line and standby cylinders, it breaks loose from the hoist. The cylinder pulls loose at one end either because of hoist failure or improper hook-up of the hoist to the cylinder. The cylinder falls, striking the online cylinder, causing it to break away from the pigtail and in turn rotate 180 degrees, allowing liquid chlorine to leak out. The standby cylinder comes on line as the switchover valve senses the drop in pressure. It leaks gaseous chlorine out of the manifold where the on-line cylinder has pulled loose. Both liquid and gaseous chlorine are released through a 5/16 inch hole. The double doors to the scale/manifold room are open to the outside, presenting the potential for off-site consequences. From Table 4-13, the release rate of liquid chlorine from a 5/16 inch hole is 240 lb/min. In addition from Table 4-15, gaseous chlorine will be leaking at a rate of 15 lbs / min. through a 5/16 inch hole as well. The combined total release rate of 255 lb / min. from Table 4-12 will have a distance to toxic endpoint of .3 miles. THE GENERAL ACCIDENTAL RELEASE PREVENTION PROGRAM Because the Great Falls Facility is operated by a private firm, USFilter Operating Services, it falls under The OSHA Rule for Chemical Process Safety Management, 20 CFR 1910.119. At the local level, we are very confident that our overall accident prevention program is effective. Specific practices here at the plant that contribute to the effectiveness of the chlorine release program are: Preventive maintenance tasks of the chlorine system that include: Yearly inspections of the mechanical aspects of the hoist. Biannual inspections of all electrical aspects of the hoist to include limit switches, motor and load brakes. Complete lubrication of all hoist components every two years. Monthly inspections of the power roof ventilators. Yearly cleaning/inspection of all process water strainers in the building Complete servicing/calibration of the scale every two years. Weekly exercising of the main 8" process water strainer. Monthly inspection of the natural gas unit heaters. Quarterly inspection and exercising of all chlorine valves. Yearly servicing of the chlorine detector as per manufacturers recommendations. Monthly safety inspections that include the following: A thorough inspection of the chlorine hoist hooks and cable. Inspection of all emergency lights. Inspection of all exhaust fans and louvre systems. Inspection of the emergency eyewash and shower. Inspection of the chlorine repair kit B. Inspection of the chlorine leak detection solution (ammonia). Fire inspection of the building. Inspection of all three ultra-light SCBA's as per manufacturers recommendations. Inspection of the Chlorine cannister masks and associated cartridges. Inspection of the emergency chlorine suits/gloves. Inspection and verification of operation of chlorine alarm. Completion of all OSHA required safety training and numerous other safety training classes are conducted and/or attended yearly. Training classes held in the last year that pertain to chemical handling include: Respirator Protection; Hazard Communication; Emergency Response; Chlorine Safety; CPR; and Chemical Hygiene. Our OSHA required Chemical Process Safety Management Plan is up to date and we complete the necessary training as required. A part of the plan that we consider to be very important is the Chlorine Handling S.O.P. This S.O.P. has been extensively reviewed and revised numerous times by the Safety Committee and has been used as a guide for chlorine handling for almost 22 years, well before the PSM requirement. In addition, a complete Safety and Environmental Compliance Audit is conducted at the f acility every 2 years by USFilter corporate safety and legal personnel. In the years between audits, the USFilter Regional Safety Coordinator visits the plant to conduct a thorough safety inspection. More general practices that contibute to the effectiveness of our program are as follows: Monthly safety meetings. Monthly safety inspections of all safety related equipment. A complete accident investigation policy for all accidents, however slight. Review of new policies with all employees. Review and update of plant specific safety policies with the safety committee. Continued correction of all identified in-plant hazards. We feel we have done an exceptionally good job in this area of safety. Numerous tailgate safety sessions prior to potentially dangerous jobs. All other required policies and procedures in place and up to date. THE EMERGENCY RESPONSE PROGRAM The USFOS Great Falls Facility Emergency Response Plan is a documented plan of procedures to define responsibilities a nd to outline standard operating procedures. These SOP's address emergency options that will safeguard the health and well-being of plant personnel, minimize damage, and address other emergency issues. This plan was developed to identify the most significant unexpected events that could occur at the Great Falls Plant. The plan also defines elements of the emergency response organization by identifying those persons and positions responsible for emergency planning and implementation. Procedural guides are presented that are to be observed by designated positions, response agencies and persons in the event an unexpected situation arises. The emergency response plan addresses general emergency events, as well as 1 ton chlorine cylinder leaks, which is the most likely critical emergency at the Great Falls Wastewater Treatment Plant. Coordination with local emergency responders has been considerable. On June 11, 1998, an emergency response simulation was held at the plant. Plannin g for the emergency simulation was done jointly with the Great Falls Fire Department, the primary responder in a chlorine leak situation. The exercise involved simulation of a major chlorine leak from a one ton cylinder at the plant site. Other entities participating in the response simulation were Malmstrom Air Force Base and Montana Air National Guard emergency response personnel. The local director of the Cascade County Disaster and Emergency Services also took part in the Exercise. Training on emergency response is conducted on a yearly basis. This training involves an actual simulated emergency response situation every other year. In the year we do not conduct a simulation, classroom training is held. In the classroom, the entire emergency response plan is reviewed with particular attention given to the chlorine leak response section. Appendix E of the Great Falls Emergency Response Plan is entitled Emergency Release Reporting Standard Operating Procedurs. It discusses in detail the situations requiring reporting, which agencies to report to and provides a Release Notification Form to be used to assist in accurate and timely reporting. PLANNED CHANGES TO IMPROVE SAFETY In 1998, a 20 Year Facilities Plan was completed for the Great Falls Wastewater Treatment Plant and associated pump stations. As part of the plan, one of the recommendations made was the addition of a chlorine scrubber using caustic soda to neutralize chlorine in the event of a leak. Because it is a recommendation rather than a requirement, it is not a guarantee but at least will be discussed in detail, providing some potential for the installation. |