EAST CENTRAL REGIONAL WASTEWATER TREATMENT PLANT - Executive Summary |
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EXECUTIVE SUMMARY: The East Central Regional Wastewater Treatment Plant (ECRWWTP) operated by the City of West Palm Beach has developed this Risk Management Plan (RMP) in response to section 112(r) of the Clean Air Act (CAA). This guidance complies with the United States Environmental Protection Agency's (EPA) Risk Management Program (RMP) regulations, 40 CFR Part 68, and the Occupational Safety and Health Administration's (OSHA) Process Safety Management (PSM) Standard 29 CFR 1910.119. Section 112(r) requires facilities which store certain toxic or flammable chemicals above threshold quantities to develop and implement an RMP. The RMP evaluates the worst case and alternative case release of these chemicals into the environment and the impact on surrounding human populations and environmental receptors. The worst case release scenario assumes that all of the toxic substance within a system or process is released at one time. The alternate case release scenario assumes a smaller, more realistic, release of perhaps one cylinder or container. The RMP also evaluates the facility's resources to cope with chemical releases and implemented procedures responding to chemical releases. Although this RMP presents worst case and alternative case scenarios, it should be noted that there has never been an incident at the ECRWWTP which resulted in any offsite consequences or injury to human health or the environment. The ECRWWTP has an average capacity of 55 million gallons per day, (mgd) with an ultimate treatment and disposal capacity of 98 mgd. The plant site consists of 300 acres. The plant layout was specifically designed to take advantage of the prevailing southeastern sea breeze. In this manner any odors created would be dissipated over the plant site and sparsely populated surrounding areas. The ECRWWTP provides wastewater treatment service to five government entities which participated in its development. The following are the five entities: City of West Palm Beach, Town of Palm Beach, City of Riviera Beach, City of Lake Worth, and Palm Beach County. The East Central Regional (ECR) wastewater treatment plant currently serves 350,000 people in central Palm Beach County and nearby communities. The ECRWWTP represents a cumulative investment of more than 63 million dollars since its inception in 1970. The plant has undergone several expansions in its nearly 30-year history. The original extended aeration facility was constructed in two stages and completed in 1980. The original design provided a minimum of 90% biochemical oxygen demand (BOD) and suspended solids removal prior to disposal of the effluent by deep well injection. Between 1980 and 1986, improvements were made to the original facility. In 1986, a major program was initiated to reduce annual operating costs and to expand plant capacity. Chlorine is the only chemical used at this facility at quantities above the EPA - List of Regulated Toxic Substances and Threshold Quantities for Accidental Release Prevention, and thus chlorine is the basis of this RMP. The ECRWWTP uses chlorine for emergency operations only, it is not used during normal operating conditions. Chlorine is used in the disinfection phase of the wastewater treatment operation in times of emergency only. The liquid effluent which is discharged from the clarifier enters the contact chamber. At this time the effluent is treated with chlorine gas. The chlorine is stored in 2,000 pound capacity containers as a liquid under pressure, but is discharged into the wastewater as a gas. The contact chamber has a series of baffles which ensure that chlorine will have a minimum reaction or contact time of 15 minutes in order to mix the liquid to kill the pathogenic bacteria in the effluent and complete the disinfection phase. Chlorine is one of the chemical elements and is one of the halogens. Neither the gas nor the liquid is explosive or flammable, however, both react chemically with many substances. Chlorine is a hazardous chemical that can cause severe injury or death if released to the atmosphere. Chlorine gas is primarily a respiratory irritant. In sufficient concentrations, the gas irritates the mucous membranes, the respiratory system and skin. At higher levels there is vomiting associated with labored breathing. In extreme cases difficulty in breathing may increase to the point where death can occur from suffocation. Chlorine is also hazardous to the environment. Chlorine causes bleached spots on leafy plants due to an attack on chlorophyll in the leaf. Mammalian animals suffer many of the same effects as humans exposed to chlorine, and many forms of aquatic animal life are adversely affected by chlorine in concentrations well below 0.1 ppm, but harmful concentrations are unlikely unless chlorine is discharged directly into water. Worst Case Scenario - The worst case scenario is based upon a complete release of the entire quantity of a toxic substance w ithin the largest vessel. This worst case scenario is based on a release of 2,000 pounds of chlorine. This scenario assumes that 2,000 pounds of chlorine is released in a duration of 10 minutes (EPA standard). The predicted wind speed is 1.5 meters per second (EPA standard). Passive mitigation is permitted for this scenario, but active mitigation is not allowed. Based on these assumptions, if a release of 2,000 pounds of chlorine occurred, the toxic endpoints would extend 3.0 miles from the source of the release. A toxic end point is the distance the released gas would travel, assuming all of the released gas moves in the same direction, and still cause noticeable health effects. If this release did occur, the contamination zone would depend upon wind direction and speed. The prevailing winds for this facility are out of the southeast which would dissipate the gas over a sparsely populated area. The human population within the 3.0 mile radius around the facility is 27,680 individ uals (based on 1990 census data). The Environmental Protection Agency RMP Comp. version 1.06 computer software was used to calculate the toxic endpoint. Alternative Case Scenario - The alternative case scenario is based on a partial release of a toxic substance from a system or process. This type of release may result from a ruptured container, ruptured seal, or broken valve. This alternate case scenario is based on a release of 2,000 lbs. (one container) of chlorine under the following conditions: 1 inch rupture in the container (diameter of valve opening); container is under 35 psi (Chlorine Institute, Inc. standard); the container temperature is 77x F (average ambient temperature); release duration is 34 minutes (time to empty container); and wind speed is 3 meters per second (EPA standard). Under these conditions the distance to the toxic end is 0.4 miles. The human population within the 0.4 mile radius around the facility is 67 individuals (based on 1990 census data). There are no public or environmental receptors inside the 0.4 mile radius. The Environmental Protection Agency RMP Comp version 1.06 computer software was used to calculate the toxic endpoint. PREVENTION: The plant was awarded Best Operated Wastewater Treatment Facility in the South-East District by the State of Florida Department of Environmental Regulation (FDER) in 1983. Numerous precautions are taken at the ECRWWTP to prevent the accidental release of chlorine gas into the atmosphere, and to minimize the consequences if a release does occur. As mentioned earlier, the plant is located in a sparsely populated area with prevailing southeastern winds which will dissipate the gas over the plant site and sparsely populated surrounding areas. Chlorine Containers - The chlorine is stored and discharged from one ton capacity containers. The containers are welded tanks with the heads convexed inward and forge welded to the barrel. The sides are crimped inward at each end to form chimes which provide a substantial grip for lifting beams. The container valves are protected by a removable steel valve protective housing. All ton containers are equipped with fusible metal pressure relief devices. The fusible metal is designed to yield or melt between 158x F and 165x F to relieve pressure and prevent rupture or the container in case of a fire or other exposure to high temperature. Chlorine System - The system has process controls, and a monitoring and detection system. When in use the process between the evaporator and the basins is under a vacuum, therefore, any leaks causing a change in vacuum shuts down the chlorinator. In addition, all underground chlorine piping is within secondary containment. Process controls in place between the one ton containers, flexible connector, header valve, evaporator, and chlorinator is a Standard Operating Procedure (SOP) to check for leaks prior to placing the containers on line, routine replacement of any gaskets or valve s, and chlorine leak detection device. Active mitigation - The chlorine system is an alarmed system. If there is a release of chlorine an audible alarm sounds, an indicator light illuminates, and the computer system indicates the release in the main office building. Budgeted for fiscal year 1999-2000 is the installation of a chlorine scrubber system. Passive mitigation - Currently there is no passive mitigation at the ECRWWTP. Budgeted for fiscal year 1999-2000 is the enclosure of the chlorine storage area. Maintenance - The alarm system is tested every two weeks. Chlorine repairs kits are kept onsite for emergency operations. An annual safety inspection is performed at the ECRWWTP Plant by Mark Waring, Environmental Health and Safety Officer, City of West Palm Beach. Personnel - The personnel involved in this process are licensed operators. One operator per shift attends an annual Trouble shooting of Chlorine- Safety and Response course. Additionally, one operator at tends an eight (8) week Hazmat/First Responder course at the South Technical Fire Academy. The Hazmat/First Responder course is refreshed annually with a one day course. General Accidental Release Prevention Program - A test is run once per month on the chlorination system. Approximately four to six one ton containers are in the chlorine building at any given time. Emergency Response Plan / Procedures - The wastewater treatment plant maintains a written Emergency Response Plan. The basis of the plan is if a chlorine leak occurs the utility personnel can take defensive measure to seal the leak. Defensive measures are defined as closing valves, such as cylinder valves and header valves. In the event that a leak cannot be stopped by simply closing a valve or valves, the utility personnel evacuate the area of the cylinder leak to a safe distance to await Fire/Rescue personnel. Utility personnel notify West Palm Beach Fire Department by a designated red telephone or by calling 911. The Fire/Rescue personnel then take charge of the situation with assistance from utility personnel. If additional assistance is needed, the West Palm Beach Fire Department will call upon the Palm Beach County Fire/Rescue personnel. Hazmat Response / Procedures - The West Palm Beach Fire Department has established a two tiered approach to incidents involving hazardous materials. First, all emergency response personnel will be trained as operational first responders. The second level of response will be a Hazardous Materials Response Team specially trained and equipped to conduct offensive operations at a Hazardous Materials incident. Prior to assignment of the West Palm Beach Fire Department Hazardous Materials Team, an individual must conform to the following criteria: 1. Have successfully completed Hazardous Materials Technician Course and have demonstrated the competencies outlined in the 1992 edition of the National Fire Protection's Pamphlet 472. 2. Have com ple ted a baseline medical exam pursuant to 29 CFR 1910. 120 and have been determined by the examining physician to be free of any medical conditions which would place the employee at increased risk of impairment of the employee's health from work in hazardous materials emergency response. 3. Hold a current certification as a State of Florida Emergency Medical Technician, and / or Paramedic. 4. Demonstrate a working knowledge of Special Operations 5's layout, equipment locations and functions. 5. Have a working knowledge of the West Palm Beach Fire Department's Haz Mat Team Standard Operations Procedures. Hazardous Materials incidents are categorized into the four following levels based on the intensity and quantity of the release: Level I - A Level I incident is a minor situation. A category I incident is defined as a release of less than 25 gallons liquid or less than 50 pounds solid of a known hazardous material. Level II - A Level II incident is one in whic h a more serious threat is posed by the release or potential release of hazardous materials. Level II incidents require the definite assistance and intervention by a Hazardous Materials Team. Level III - A Level III is a major incident requiring specialized assistance and may require assistance from support agencies. A formal command post, staging area and medical and / or rehab group is established. The establishment and control over isolation (hot) zones is included. Level IV - A Level IV incident is a local disaster. This type of incident will severely strain or exceed the capabilities of local response agencies. A long-term command post may be required. It may require the activation of an Emergency Operations Center. The following procedures will be followed during an incident: The first fire / rescue unit arriving at a Hazardous Materials incident shall establish command, utilizing a unit or geographic location to identify command. The Haz Mat Group shall report direct ly to the Incident Commander. The Had Mat Group is responsible for recommending evacuation distances, obtaining information concerning the hazards and risks posed by the materials in question, recommending decontamination and safety measures, recommending possible mitigation efforts and provide other technical assistance. The Incident Commander retains overall control and authority during the entire operation, and the Had Mat Group shall perform mitigative actions. See Appendix B for complete West Palm Beach Fire Department Hazardous Materials Response Plan. If additional Had Mat Teams are needed the Palm Beach County Regional Hazardous Materials Response Teams (PBCRHMRT) assists the West Palm Beach Fire Department with hazardous materials incidents. The PBCRHMRT has an Emergency Management Plan which supplements the plan of the West Palm Beach Fire Department. See Appendix C for complete PBCRHMRT Emergency Response Plan. Planned Changes to Improve Safety - Standard Operating Procedures (SOPs)are to be updated by June 30, 1999 and will include procedures for calibration of the chlorine alarm system, for chlorine leak tests, for operator notification when chlorine is detected, and emergency response. Budgeted for fiscal year 1999-2000 is the enclosure of the chlorine storage area and installation of a chlorine scrubber system which would substantially reduce the likelihood of an offsite chemical incident. |