Quonset Point Wastewater Treatment Facility - Executive Summary |
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Rhode Island Economic Development Corporation EPA Risk Management Plan June 21, 1999 Executive Summary General Policy The Rhode Island Economic Development Corporation (RIEDC) recognizes that the safety of their employees and the general public is one of their greatest responsibilities. Therefore, RIEDC continues to develop maintenance, inspection, training, and review programs to reduce the likelihood, or effects of, accidents within their facilities. Regulated Substances RIEDC operates the Quonset Point Wastewater Treatment Facility at North Kingstown, Rhode Island. Chlorine is the only substance at this facility that is considered a "Regulated Substance" by the Environmental Protection Agency (EPA). Chlorine is classified as a toxic gas, which, when improperly handled, may affect the health of the workers or the surrounding community and environment. Under normal operating conditions, chlorine gas is mixed with potable water to create a chlorinated water solution for disinfec ting the plant effluent. This solution is formed with a vacuum type chlorination system, which causes gaseous chlorine to flow from one-ton cylinders, through a vacuum regulator, a chlorinator, and through an ejector. The chlorinator controls the gas flow rate and the ejector creates the vacuum and is the site where the chlorine gas is mixed into the potable water to form the chlorine solution. The chlorine is under a vacuum between the vacuum regulator and the ejector. Control of plant effluent disinfection is accomplished with an automatic chlorine feed system. This system utilizes a chlorine residual analyzer and plant effluent flow signals to continuously adjust the chlorine feed rate. The chlorine is stored in two 2,000-pound chlorine storage cylinders, which are located within an enclosed chlorine building. Worst-Case Release Scenario RIEDC has determined a worst-case scenario related to the release of chlorine. During a worst-case release, the chlorine gas would escape from one (1) 2,000-pound chlorine cylinder at a rate of 200 lbs./min. over a 10 minute period. Due to the flat and relatively unobstructed terrain, a worst-case release from the chlorination process would affect any public or environmental receptor within a 3.0 mile radius of the facility, which includes portions of North Kingstown and Jamestown, RI. Outside this radius, the chlorine gas concentration falls below the 0.0087 mg/l level that has been established by the EPA as the toxic endpoint. Within the affected area, public receptors including schools, residences, industrial facilities, commercial/office areas, recreation areas, and boats could be exposed to concentrations above the threshold exposure limit. There are no national or state parks, forests, or wildlife refuges within the 3-mile radius. The ocean, however is within the 3-mile radius. The affected residential population is approximately 12,200 persons. Alternative Release Scenario RIEDC has also determined an a lternative release scenario. During the alternative release, chlorine gas would escape as the result of a failure of the vacuum regulator, which could result in the release of 2,000 pounds of chlorine at a rate of 37 pounds/minute for 54 minutes. The affected area would be limited to 0.3 miles. Public receptors, including industrial facilities and commercial/office areas, would be affected. The ocean is the only environmental receptor that could be affected. No residential population would be affected. General Accidental Release Prevention Program RIEDC recognizes that prevention is an essential element in reducing accidents within their facility. The plan includes the following: Safety System - A leak sensor inthe chlorine cylinder storage room and in the chlorinator room actuates the plant alarm system to alert personnel that a leak has occurred. Self-contained air packs are located at the Chlorine Building and in the operations Building. Personnel entering an area with a chlorine leak will use these air packs. Additionally, a Chlorine Institute Kit "B" for repairing cylinder leaks is located in the Chlorine Building. Operations - Plant personnel use standard procedures for unloading chlorine cylinders from the delivery truck, for disconnection a spent cylinder, and for connecting up a fresh cylinder. The procedures includeusing new tubing each time a fresh cylinder is connected to a vacuum regulator, using new lead washers for the tubing connections, and testing all connections for leaks with ammonia. Training - By August 1, 19999 the plant will implement a chlorine training program for new employees and will implement periodic refresher training for existing employees. Training will cover safe handling practices, preventive maintenance, and emergency response procedures for handling chlorine leaks. The training program will comply with 40 CFR 68.54. Preventive Maintenance - Preventive maintenance on the chlorine system components that handle ch lorine gas - mainly the vacuum regulators and the chlorinators - is handled by the component manufacturer through a service contract. The manufacturer services the equipment quarterly. Plant personnel maintain the chlorine ejectors on a regular basis. By August 1, 1999, the plant will develop and implement a written preventive maintenance program which will comply with 40 CFR 68.56. The Five-Year Accident History No known significant spills or leaks have occurred at the Quonset Point Wastewater Treatment Plant that have resulted in on- or-off-site consequences during the last five years. Emergency Response Program An emergency response plan has been developed. An emergency coordinator and two alternative individuals have been identified. The emergency coordinator is responsible for determining if an emergency situation warrants a planned evacuation and implementation of this plan. The plan includes information related to management of the plan, evacuation of employees, respons e actions and reporting. In the event of an emergency situation, the emergency coordinator will be notified first. Upon decision to implement the emergency response program, all facility personnel, appropriate State, Federal, local agencies, and fire and police departments will be notified as deemed necessary by the emergency coordinator. At a minimum, the following agencies shall be notified: North Kingstown Fire Department (401) 294-3344 United States Coast Guard (401) 846-3675 Marine Safety Office (401) 435-2300 National Response Center (202) 267-2675 RI Department of Environmental Management Hazardous Materials (401) 222-2797 24-Hour Line (401) 222-3070 RI Department of Health Office (401) 222-6867 Fax (401) 222-6953 Pager (401) 272-5952 Local Emergency Planning Committee (401) 461-4161 The North Kingstown Fire Department is the local agency that coordinates the emergency response activities. They have the responsibility to provide assistance related to the notifications, evacuation, and on site response. Changes to Improve Safety The following changes to improve safety are currently being considered by RIEDC: 7 Install two fail-safe type chlorine detectors, one dedicated to the chlorinator area and one to the chlorine storage area. (The detector control and transmitter units would be installed in the Sampler Room.) 7 Install a panic button connected to an alarm in the chlorine Sampling Room for the safety of the person performing sampling. Also install a phone in the Sampling Room. 7 Install a window, a light, or some other means of identifying when personnel are in the sampling room. 7 Install a windsock, or other wind directional device, to allow employees to identify the prevailing wind direction in case of an accidental release. 7 Connect the chlorine leak alarm signals from the detector unit in the sampler room to the alarm panel in the main office so that the personnel can acknowledge the exact loca tion of the chlorine leak. Also, connect the chlorine alarm signals to the North Kingstown Fire Department for an immediate response. The chlorine signal would be differentiated from the general operations alarm. 7 Locate the new chlorine sensors to a lower height than the existing sensors. It is possible that the sensors at their present height of 2-ft. may not immediately detect the heavy chlorine gas when released because chlorine gas tends to travel close to the floor. 7 Have a master key for all for the rooms in the chlorine building. 7 Have a master facility key. 7 Have a steel clipper in the control room at all times for easy access into the B-kit. |