Grand Glaize Wastewater Treatment Plant - Executive Summary |
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I. INTRODUCTION This document contains all the information necessary for the MSD Grand Glaize Wastewater Treatment Facility (Grand Glaize) to meet the requirements of 40 CFR 68 "Risk Management Program". II. RELEASE PREVENTION AND EMERGENCY RESPONSE POLICIES Grand Glaize uses chlorine and sulfur dioxide for wastewater treatment. Chlorine is used as a disinfectant and sulfur dioxide is used to de-chlorinate the treated wastewater. Both chlorine and sulfur dioxide are regulated toxic substances under 40 CFR 68 and are potential health hazards if not handled properly. Grand Glaize adheres to all applicable Federal, state, and local rules and regulations to ensure a safe environment within the plant as well as for the surrounding community. Access to the chlorine and sulfur dioxide systems is restricted to certified operators, authorized contractors, and the City of Valley Park fire department (the primary responder in the event of an accidental release). The Grand Glaize plant i s not a primary emergency responder in the event of an accidental release but the plant is included in the community emergency response plan developed under 42 U.S.C. 11003. Procedures are in place for notification of the Valley Park fire department (primary responder), the LEPC and the St. Louis County HAZMAT team. III. PROCESS DESCRIPTION AND REGULATED SUBSTANCES The Grand Glaize plant in Valley Park, Missouri is a wastewater treatment plant. Chlorine and sulfur dioxide are used in the wastewater treatment process for final effluent chlorination and dechlorination. The chlorination and dechlorination process occurs during the months of April through October. Typical consumption rates for the gases are approximately 500 lbs/day of chlorine and 250 lbs/day of sulfur dioxide. The North American Industrial Classification System code (NAICS code) for the primary process at this facility is 22132. Typically, ten 1-ton containers of chlorine and six 1-ton containers of sulfur diox ide are stored on site at any given time. The on-line chlorination system includes four 1-ton containers in two manifolded sets of two with an automatic switchover valve between the two sets. All four containers are housed inside the chlorination building located on the west side of the plant. The rest of the chlorine containers are stored in a protected area outside the chlorination building. The on-line sulfur dioxide system consists of two 1-ton containers. When one container is emptied, the other container is switched over manually. Two more 1-ton containers are stored next to the two that are on-line and all four containers are housed in a separate room within the chlorination building. The 1-ton containers (both chlorine and sulfur dioxide) are delivered and stored outside the chlorination building, and conveyed into the building by monorail operated and maintained by trained MSD personnel. Both chlorine and sulfur dioxide are regulated substances under 40 CFR 68. The chl orine threshold for triggering applicability of 40 CFR 68 is 2,500 pounds and the sulfur dioxide threshold is 5000 pounds. The maximum quantity of chlorine stored on-site at any one time is 20,000 pounds and the maximum quantity of sulfur dioxide stored is 12,000 pounds. Since this exceeds the threshold limit, Grand Glaize is subject to 40 CFR 68 as a Program 2 facility. IV. WORST-CASE AND ALTERNATIVE RELEASE SCENARIOS IV.1 Worst-case Scenario For Grand Glaize, the worst-case scenario is the loss of 2000 pounds of chlorine in ten minutes from a 1-ton container located outside of the chlorination building. Since the facility is located in a populated area, the worst-case scenario would affect nearby public receptors. IV.2 Alternative Release Scenario Chlorine The alternative release scenario examined involves the release of chlorine due to a flashing liquid release through a <" diameter (approximate) rust hole at the liquid level of the 1-ton container. Passive mitigation is considered in this case as the 1-ton container is assumed to be housed in the chlorination building. Since the facility is located in a populated area, the alternative release scenario would affect nearby public receptors. Sulfur Dioxide The alternative release scenario examined involves the release of sulfur dioxide due to a flashing liquid release through a 3/8"diameter (approximate) rust hole at the liquid level of the 1-ton container. Passive mitigation is considered in this case as the 1-ton container is housed in the chlorination building. Since the facility is located in a populated area, the alternative release scenario would affect nearby public receptors. V. GENERAL ACCIDENTAL RELEASE PREVENTION PROGRAM AND CHEMICAL-SPECIFIC PREVENTION STEPS This facility complies with EPA's Accidental Release Prevention Rule and with all Federal, state and local codes and regulations. The plant continually conducts inspections to ensure the system is intact and operating correctl y. These inspections ensure that the worst-case and alternative scenarios have a minimal chance of occurring. The plant has developed a prevention program for chlorine and sulfur dioxide to meet the Program 2 requirements of the RMP rule. The prevention program was developed to comply with 40 CFR 68, to ensure the safety of the employees, and to ensure the safety of the surrounding community. The program covers a compilation of safety information, periodic conduct of hazard reviews, operating procedures, training, maintenance, compliance auditing and incident investigation. VI. FIVE-YEAR ACCIDENT HISTORY The review of this facility's accident history includes the following range of dates: June 22, 1994 - June 21, 1999. There have been no releases at this facility as defined in 40 CFR Part 68.42(a). VII. EMERGENCY RESPONSE PROGRAM As mentioned earlier, in Section 1.0, the Grand Glaize Plant is not a primary emergency responder in the event of an accidental release but the pla nt is included in the community emergency response plan developed under 42 U.S.C. 11003. Procedures are in place for notification of the Valley Park fire department (primary responder), the LEPC and the St. Louis County HAZMAT team. The Valley Park Fire Department is notified by calling 911. The Grand Glaize Plant has developed an emergency evacuation document. The purpose of the document is to provide an orderly, effective plan of action for protecting employees in emergency situations when an evacuation is necessary. VIII. PLANNED CHANGES TO IMPROVE SAFETY Based on the "what-if/checklist" Hazard Review completed for chlorine and sulfur dioxide, a list of action items was developed for implementation. The following examples briefly describe improvements occurring as a result of the Hazard Review. 1. All system components referenced in the operating procedures will be tagged for reference. 2. Additional precautions will be taken to avoid taking delivery of a container that may be overfilled. 3. The delivery truck will be chocked while unloading. 4. Test schedules will be developed for chlorine monitors. 5. Hydrostatic container tests will be checked to see if current. 6. An automatic container shut-off valve will be installed and will be activated by area monitors with manual override. |