Hap Cremean Water Plant - Executive Summary |
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?68.155(a) Accidental Release and Emergency Response Policies The Hap Cremean Water Plant has documented emergency response procedures in place, as documented in the facility's Emergency Action Plan. This plan has been endorsed by the City staff responsible for the operation and maintenance of the Hap Cremean Water Plant. The Hap Cremean Water Plant has procedures in place, including both onsite activities and coordination with offsite responders, that must be followed in the event of a chlorine leak. All personnel involved in handling chlorine are trained with regard to chlorine safety and accident prevention. ?68.155(b) Stationary Source and Substance Handled The stationary source subject to 40 CFR Part 68 is the City of Columbus Hap Cremean Water Plant Chlorination Facility. The Hap Cremean Water Plant has a design capacity of 130 million gallons per day (MGD) and treats surface water to drinking water standards. Facilities are provided for the handling and utilization of ch lorine in one-ton containers. The Chlorination Facility is located on the northwest side of the plant and consists of the following areas: an enclosed Chlorine Container Storage and Unloading Room, two chlorinator rooms and two evaporator rooms. The chlorine ton containers are stored inside the enclosed Chlorine Container Storage and Unloading Room. The doors and windows in these rooms are normally kept shut. A monorail and hoist assembly is provided for the handling and transfer of the one-ton containers to the storage facilities from flat-bed delivery trucks or from storage to the scale assemblies for process use. Provisions are made to house fifty-two (52) one-ton containers of chlorine, forty of which are stored on trunnions on the floor. Therefore the maximum intended inventory of chlorine at the Hap Cremean Water Plant is 52 full one-ton containers of chlorine or approximately 104,000 lbs of chlorine. The Chlorine Container Storage and Unloading Room is equipped with two w eigh-scale banks that can hold six connected one-ton containers of chlorine each. Normally, one bank has six full containers of chlorine connected to the manifold/header system with only one of the ton container of chlorine in service at a time. When the in service container approaches empty, the container is shut off and the next full container in the bank is opened and put in service. The one-ton containers are connected to feed liquid chlorine through the system. The manifold piping has an expansion tank with a rupture disk that will relieve pressures in excess of 400 psi in the liquid line. There are two evaporator rooms, Plant "A" and Plant "B", that each house two evaporators. Normally one evaporator is in use at a time, with the others on stand-by. The chlorine gas remains under pressure as it leaves the evaporator and is then dropped to a vacuum at the vacuum regulator. From the vacuum regulator, chlorine is fed under a vacuum to the chlorinators. There are two chlorinator rooms, Plant "A" and Plant "B", that each house four chlorinators. The four chlorinators are considered "pre-", "intermediate", "post", and "stand-by" to designate their normal points of application in the plant. Nine water injectors are provided for solution chlorine feed at various process locations. There are seven chlorine leak detectors in the chlorine building. Three detectors are located in the Chlorine Container Storage Room, one is located in the Unloading area, and two are located adjacent to each bank of connected one-ton containers. There is one chlorine leak detector in each of the other four rooms ("A" and "B" Chlorinator Rooms and "A" and "B" Evaporator Rooms). These leak detectors alert the plant staff quickly in the event of a chlorine leak. All of the leak detectors are mounted on the wall of the Chlorine Container Storage Room, with the actual sensor in the appropriate room. The leak detectors are set to alarm at 2 ppm. The alarm activates local buzzers and li ghts on the detector, buzzer indicators and lights at the remote alarm panel in the filter building, and buzzer indicators and lights on the remote panel outside of the laboratory area. The remote panel in the filter building also indicates in which room the leak was detected. The alarm notifies the plant SCADA System and indicates in which room the leak occurred, an audible horn is sounded outside of the chlorine rooms in the breezeway, the building ventilation system is shut down, and the scrubber make-up air vents are opened. ?68.155(c) Offsite Consequence Analysis As a Program 3 Process with one toxic gas, one worst-case release scenario and one alternative release scenario will be addressed for the Chlorination Facility. The Hap Cremean Water Plant has chosen to use the US EPA Risk Management Program Guidance for Wastewater Treatment Plants (40 CFR Part 68), US EPA 550-B-98-010, October 1998, (WWTP Guidance), as a source to determine off-site consequences. This guidance spe cifically addresses the chemicals commonly found at WWTPs. The chlorination process for Water Plants is similar to the chlorination process at WWTPs. Therefore, this guidance document is applicable to the Hap Cremean Water Plant's chlorination process. The worst-case release scenario was determined in accordance with the requirements provided in 40 CFR 68.22 and 40 CFR 68.25(b,c). For the Hap Cremean Water Plant facility the worst-case scenario is a total release from one of the one-ton containers of chlorine (greatest amount held in a single vessel) in 10 minutes. This results in offsite impacts.The facility is also required to complete at least one alternative release scenario that reaches an endpoint offsite. The alternative release scenario was evaluated in accordance with the guidelines provided in 40 CFR 68.22 and 40 CFR 68.28. The most likely release scenario was identified based on the results of the Process Hazard Analysis (PHA). The alternative release scenario for chl orine that results in offsite impacts is a flashing liquid release through a 3/16 inch opening in a leaking flexible tubing line, valve connection, process piping or equipment. ?68.155(d) Accidental Release Prevention Program The Hap Cremean Water Plant facility has a documented Prevention Program for the chlorination facility that documents release prevention measures. These prevention measures include elements such as Employee Participation, Process Safety Information, Process Hazard Analysis, Operating Procedures, Training, Contractors, Pre-startup Review, Mechanical Integrity, Hot Work Permits, Management of Change, Incident Investigation, and Compliance Audits. As mentioned previously, Hap Cremean Water Plant is equipped with leak detection monitoring to decrease response time in the event of a chlorine leak. Leak detectors are installed in the Chlorine Storage Room and the Chlorine Feed Room. Also, Hap Cremean Water Plant employees who are involved in chlorine operations ar e trained in specific procedures regarding handling and storage of chlorine at the facility. ?68.155(e) Five-Year Accident History The Hap Cremean Water Plant facility has had no accidental releases of chlorine in the last five years that have resulted in on-site injuries or off-site injuries or other impacts. ?68.155(f) Emergency Response Program The Hap Cremean Water Plant is a non-responding facility, as defined by OSHA and USEPA (29 CFR 1910.120 and 40 CFR part 311). Therefore the Hap Cremean Water Plant has developed an Emergency Action Plan to ensure employee safety instead of an Emergency Response Program, as allowed by 40 CFR 68.90(b). The Hap Cremean Water Plant facility Emergency Action Plan outlines actions required to respond to a chlorine emergency and has coordinated this plan with the City of Columbus Fire Department- Haz Mat Station 4. The Fire Department personnel are the designated first responders in the event of a chlorine emergency. Hap Cremean Water Plant employees are not designated responders to a chlorine release. As specified in 40 CFR 68.90, Hap Cremean Water Plant's Emergency Action Plan meets the exception listed in 40 CFR 68.90(b) and therefore, the facility is not required to have the Emergency Response Program of 40 CFR 68.95. ?68.155(g) Safety Improvements Recommendations for safety improvements were identified in the Process Hazard Analysis (PHA) which was completed per OSHA 29 CFR 1910.119(e) in November of 1999. Recommended improvements were identified in four main categories: Standard Operating Procedures, Administrative, Engineering, and Training. According to the Process Safety Management Plan, any safety improvements will be investigated concerning their impacts on other systems and/or procedures prior to implementation. Additional recommendations may be made upon review of any accidents and/or when the PHA is updated every five years. |