Kalamazoo Water Reclamation Plant - Executive Summary |
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Owned and operated by the City of Kalamazoo, Michigan, the Kalamazoo Water Reclamation Plant (KWRP) receives and treats wastewater from residential, commercial, and industrial sources. The City has contractual agreements with numerous surrounding governmental units and industries to treat wastewater generated outside the city limits of Kalamazoo. The design flow rate is 54 million gallons per day (MGD) and the average daily flow rate is currently about 30 MGD. Wastewater entering the KWRP receives pre-treatment (screening), primary treatment (grit removal, clarification, etc.), secondary treatment (powdered activated carbon-enhanced activated sludge), and tertiary treatment (ammonia and phosphorus removal, chlorination and de-chlorination). The KWRP uses chlorine to disinfect the treated wastewater prior to discharge to the Kalamazoo River. Chlorine is a regulated chemical under OSHA's Process Safety Management rules and under USEPA's Chemical Accident Prevention rules. Chlorine is delivered to the KWRP and used in one ton containers. Six to ten full chlorine containers are delivered to the site via truck by the supplier. The containers are unloaded and stored in an outdoor, covered storage area. The containers are moved into a chlorination room when needed. In this room, KWRP staff connect the ton containers to the feed system. The KWRP uses vacuum feed systems that are inherently safe. These systems involve the use of water flowing through an eductor which creates a vacuum. This vacuum allows for the feed of chlorine from the containers into the piping system. If a chlorine line downstream of the vacuum regulator is broken or develops a leak, the vacuum is interrupted and the vacuum regulator automatically closes, preventing the discharge of chlorine. The KWRP has developed a comprehensive, accidental release prevention program as part of the OSHA PSM program. The elements of this program include: 7 Process Safety Information 7 Process Hazard Anal ysis 7 Operating Procedures 7 Training 7 Management of Change 7 Pre-Startup Safety Review 7 Compliance Audits 7 Incident Investigation 7 Contractor Management 7 Hot Work Permits 7 Incident Investigation The facility has coordinated its emergency response activities with the Kalamazoo Department of Public Safety. The worst-case release scenario has been defined by the USEPA in a guidance document specifically developed for wastewater treatment plants. The worst-case release scenario involves the rupture and complete loss of chlorine from a full one ton container outside the chlorine room at the KWRP. The distance to the specified endpoint (3-PPM chlorine in air) is estimated to be 1.3 miles. This distance was estimated using USEPA's tables provided in the guidance material. The worst-case release scenario does not take into account any administrative controls or passive mitigation measures. An alternative-case release scenario was also performed based on the experience of plant o perators. The alternative scenario considers a leaking gasket at the connection between the chlorine container and the valve/piping system while the system is operating. It is assumed that the windows and doors of the chlorine building are closed and the ventilation fan is running, exhausting fumes to the atmosphere. It is also assumed that the chlorine leak detectors sense the chlorine gas and a response curtails the release in 10 minutes. The distance to the specified endpoint (3-PPM chlorine in air) is estimated to be 0.2 miles. This distance was estimated using USEPA's tables provided in the guidance material. In the past five years, there have been no accidental releases of chlorine at the KWRP that have resulted in deaths, injuries, or significant damage on site, or known offsite deaths, injuries, evacuations, sheltering in place, property damage, or environmental damage. An Emergency Response Plan has been developed for the site. This plan, which has been submitted to the Local Emergency Planning Committee, contains measures that KWRP staff can take to alert employees to a release, personal protective equipment, how to distinguish between an incidental release and a significant release, and many other elements. KWRP staff receive training to allow for offensive remedial action in response to an on-site release. Some staff receive training for incident command practices. In addition, the KWRP performs periodic drills of the emergency response plan. |