Water Treatment Plant No. 6 - Executive Summary |
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Background Water Treatment Plant (WTP) No. 6 is one of four plants owned and operated by the City of Maitland that contributes to the city's potable water supply. Total population served is approximately 14,600. In the process of developing raw water to a product that is suitable for domestic use, chlorine is used as a disinfectant against pathogens at each of these plants. The Clean Air Act section 112 ( r ), lists chlorine as a regulated toxic substance. Plants that store amounts of a regulated substance greater than their respective threshold listed in Table 1 of 40 Code of Federal Regulations (CFR) part 68.130, must comply with the provisions of 40 CFR part 68- the Risk Management Program (RMP). WTP No. 6 has a maximum inventory of 10,250-lbs of chlorine gas which surpasses the 2,500-lb threshold for chlorine. For this reason, WTP No. 6 must meet the terms set forth in the Risk Management Plan. Hazard Assessment As part of the RMP, an offsite consequence analysis (OCA) was c onducted to determine the potential area effected by a worst-case and alternate release scenario and disclose the offsite public and environmental receptors affected by these scenarios. A brief description of the scenarios and their results follows: The worst case scenario was modeled using the EPA's OCA Guidance Reference Table 4-3 and considered a 1-ton chlorine cylinder releasing its full contents in ten minutes. It was determined that this scenario would have an impact on offsite public receptors located within a 3-mile radius from the plant. The alternate release scenario considered a failed chlorinator with = inch hole in the 5/8-inch polyethylene tubing used to connect the chlorinator to the PVC gas header. Using the EPA's OCA Guidance Reference Exhibit 4-15, the release rate for a =-inch hole is 37-lb/min. It was determined that this scenario would have an impact on offsite public receptors located within a 0.3-mile radius from the plant. Prevention Program In effort to dis courage scenarios like the above from occurring, WTP No. 6 complies with the Occupational Safety and Health Act (OSHA) Process Safety Management (PSM) rule and has up-to-date technological equipment and strict procedural practices in place. The plant uses cylinder-mounted regulators that operate entirely by vacuum to eliminate leaks or breaks associated with pressure-systems. Warning devices such as a chlorine gas detector and residual analyzer are used to detect chlorine leaks. These two systems are interfaced with a control panel and a remote dialer system to alarm the appropriate personnel of the existing condition. Communication is enhanced by the use of two-way radios used by the city employees which are capable of contacting the police department in the event of an emergency. Plant procedural practices are safety oriented and include procedures for operating, inspecting, changing and maintaining chlorine process equipment. A training program is provided to familiarize city empl oyees with the chlorine process and safety equipment. Other programs are implemented to ensure information on chlorine and its hazards are available to the plant employees and contractors. Five-Year Accident History WTP No. 6 has no reportable accidental releases within the last 5-years. Emergency Response The City of Maitland Utilities will not be responding directly to non-incidental releases of chlorine gas. The local emergency responder for the City of Maitland Water Treatment Plant No. 6 will be the City of Maitland Fire Department. Note: Field Name: 7.10.a Error Message: Compliance Audit Date The above error message occurs when submittting the file from the hard drive to the 3.5 floppy disk. A compliance audit has not been completed, and the field is instructed by RMP Submit to be left blank. |