City of Lakeville Water Treatment Facility - Executive Summary |
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See attached text file. Risk Management Plan: Lakeville Water Treatment Plant Lakeville, Minnesota 3.0 Executive Summary The City of Lakeville Water Treatment Plant (Lakeville WTP) in Lakeville, Minnesota is subject to Risk Management Planning requirements of 40 CFR Part 68 due to storage of at the facility. Lakeville WTP has a maximum quantity of five (5) one ton (2,000 pounds each) cylinders of chlorine on site. A Risk Management Plan (RMP) is required because the on-site storage quantity of is above the RMP threshold of 2,500 pounds and is subject to Process Safety Management (PSM) due to the storage exceeding 1,500 pounds in a single process. This RMP needs to meet Program 3 requirements, because the chlorine storage triggers the PSM and RMP threshold quantities and the process has the potential to impact off-site receptors resulting from a worst-case release scenario. The RMP requires the Data Elements Submission, an Offsite Consequence Analysis, a Program 3 Prevent ion Program, and an Emergency Response Plan. 3.1 City Policy Lakeville WTP has developed policies for enhancement of employee health and safety and environmental management programs. Lakeville WTP is strongly committed to employee, public, and environmental safety. Each individual employee is responsible for observing all safety regulations and practicing good safety at all times. No job is too important to not take the time to perform the work safely. No operation shall be carried out until safety is assured. The Lakeville WTP is audited by corporate personnel on an annual basis to ensure continued enhancement of its health and safety and environmental programs. 3.2 Stationary Source Information Lakeville WTP is subject to Program 3 RMP requirements, because the chlorine storage is above the PSM and RMP threshold quantities and the worst-case release scenario could impact off-site receptors. Thus, an alternative release scenario was also performed. The alternative release sce nario may also be expected to impact off-site receptors. 3.3 Off-Site Consequence Analysis The worst-case release scenario would occur from the sudden release of the entire contents of one, 2,000 pound chlorine tank resulting in a toxic gas release. The alternative release scenario was determined for a pipe rupture release. The distances to the toxic endpoint for the worst-case release scenario and the alternative release scenario were 0.9 mile and 0.3 mile respectively. 3.4 Accidental Release Prevention Program Lakeville WTP has taken all necessary steps to comply with the accidental release prevention requirements set forth under 40 CFR Part 68. Lakeville WTP has developed the required elements of a Program 3 prevention program, including Safety Information, Hazard Review, Operating Procedures, Training, Maintenance, Compliance Audit, and Incident Investigation programs. In addition, Lakeville WTP has prepared an Emergency Response Plan designed for timely, safe, and efficient response to minimize hazards to human health and safety. The plan is reviewed and updated periodically to ensure that the information is accurate. 3.5 Five-Year Accident History Within the previous five years, Lakeville WTP did not have any accidental release of chlorine that caused deaths, injuries, or the need for response or restoration activities. 3.6 Emergency Response Program Lakeville WTP has written Emergency Plans and Procedures to deal with accidental releases of hazardous materials. The plan includes all aspects of emergency response actions including adequate first aid and medical treatment, evacuations, notification of local emergency responders, as well as post-incident clean-up and decontamination of affected areas. The Emergency Plans and Procedures for Lakeville WTP was last updated in May 1999. Lakeville WTP also has a spill plan to prevent and control the accidental release of hazardous waste material from this facility. 3.7 Safety Improvements Planned Lakev ille WTP will make any necessary improvements for the chlorine storage system identified through its annual maintenance check as well as the inspections prior to each use. Lakeville WTP may set up contracts with its supplier and/or qualified service companies to conduct the annual inspection and servicing the chlorine system. 3.8 General Duty Clause The RMP regulations include a general duty clause to prevent release of any hazardous material regardless of quantity stored on-site. Other than chlorine, Lakeville WTP stores additional process chemicals in enclosed designated chemical storage areas at various rooms within the building, which are equipped with spill containment and proper ventilation. The risk of releases from chemical storage areas at Lakeville WTP is low due to inherent safeguards, proper handling procedures and employee training. Thus, these activities were not included in the off-site consequence analysis for this facility. 4.0 Data Elements Lakeville WTP has comp leted the required data elements information required for RMP submission to the U.S. Environmental Protection Agency (USEPA). A diskette and printout of the data elements submission report is included on this diskette. 5.0 Off-Site Consequence Analysis The Off-site Consequence Analysis (OCA) for Lakeville WTP's RMP includes a worst-case release scenario and an alternative release scenario. The appendix of the written report includes modeling results for the quantity of chlorine released for each scenario, and a diagram showing distances to the toxic endpoint resulting from the worst-case and alternative release scenarios. 5.1 Worst-Case Release Scenario The worst-case release scenario was used to determine the greatest distance to the toxic end-point caused by sudden release of the entire contents of the largest chlorine tank. For this analysis, the toxic material endpoint would be a 0.9 mile radius caused by sudden release of one, 2,000 pound chlorine tank resulting in a liquid spill and vaporization. RMP*Comp was used for this release scenario, which is a U.S. EPA program for determination of the distances to flammable or toxic endpoints. The chlorine tank is located inside a building, which was considered for purposes of this analysis. However, in order to present the most conservative (overestimated) worst-case scenario, safeguards present at the Lakeville WTP were not considered. Lakeville WTP has a scrubber system designed to draw any contaminated air from the chlorine storage room and clean it prior to its release back into the outdoor environment. Other safeguards such as shutoff valves and such also were not considered for this scenario but are present on the system. Lakeville WTP is located in a combined urban/rural area. Urban setting was used for the most conservative release scenario. Thus, a limited amount of residential areas and two schools could be impacted by a worst-case release scenario. Based on a map showing population densit ies in the Lakeville area (1990 census data), the number of persons within the area impacted by a worst-case release scenario would be fewer than 4,800 persons. No hospitals or environmental receptors are within 0.9 mile radius of the source. 5.2 Alternative Release Scenario The alternative release scenario was used to determine the distance to the toxic end-point caused by a more likely event than the worst-case release scenario. For this analysis, the toxic material endpoint would be caused by a sudden release of contents from tank as the result of a pipe rupture release would more likely occur than a tank release due to inherent safety features of the chlorine storage tanks. Since the chlorine tank is stored and used indoors, the enclosure was considered for purposes of this analysis. However, in order to present the most conservative (overestimated) scenario, safeguards present at the Lakeville WTP were not considered. Lakeville WTP has a scrubber system designed to draw any contaminated air from the chlorine storage room and clean it prior to its release back into the outdoor environment. Other safeguards such as shutoff valves and such also were not considered for this scenario but are present on the system. Using RMP*Comp, the alternative release scenario could cause an area of impact within 0.2 mile in radius. The only off-site receptors located within a 0.2 mile radius of the source would include two schools and several houses. The estimated population (based on 1990 census data) affected by the alternative release scenario would be less than 100 persons. 6.0 Prevention Program Lakeville WTP has prepared a Program 3 prevention program according to the RMP rule. The prevention program for Lakeville WTP includes seven program elements: safety information, hazard review; operating procedures, training, maintenance, compliance audit, and incident investigation described below. 6.1 Safety Information The safety information for the chlorine storag e system includes: (1) a material safety data sheet (MSDS); (2) the maximum intended inventory of chlorine on site; (3) safe and upper and lower temperatures, pressures, flows, and compositions; (4) equipment specifications; (5) codes and standards used to design, build, and operate the process. A MSDS for chlorine, Piping & Instrumentation Diagrams (P&ID's), and safety information for the chlorine storage system at Lakeville WTP is included in the Appendices. The maximum intended inventory is five 2,000 pounds containers. The empty tanks are filled off-site and exchanged on-site with full tank The Lakeville WTP has a chlorine detection system, which detects pressure changes in the lines and will automatically shut down the system to prevent additional releases. Lakeville WTP has compiled safety information for its chlorine storage system. A process safety hazard analysis has also been conducted for this system. The safety information will be updated as needed when major cha nges are made to the system or every five years. Major modifications or changes for the chlorine storage system will be documented using a table for major changes included in the appendix of the written report. 6.2 Hazard Review The hazard review requires Lakeville WTP to identify the hazards associated with the process, opportunities for equipment malfunctions or human errors that could cause an accidental release, the safeguards used or needed to control the hazards or prevent equipment malfunctions, and any steps used or needed to detect or monitor releases. A process safety hazard analysis was conducted for the chlorine and is included in the written report. The hazard review needs to be updated at least every five years or whenever a major change is made to the system. All issues identified in the updated hazard review need to be resolved before startup of the changed process. 6.3 Operating Procedures The RMP requires written operating procedures to provide clear instruc tions for conducting activities consistent with the safety information for the process. Operating procedures include training requirements and safety and health considerations. Only qualified Lakeville WTP personnel or contractors will be permitted to perform annual maintenance checks of the system. Personnel performing maintenance or equipment changes on the chlorine storage system shall be adequately trained to understand and avoid the hazards associated with chlorine. Operating procedure guidelines are included in the appendix of the written report. 6.4 Training Annual training will be provided for all employees to assure understanding of procedures and to acquaint new staff with plant chemical and safety hazards and emergency response procedures. New staff will have these procedures explained to them during their initial operator and safety training. In particular, supervisors and managers will be instructed in the hazards and regulations associated with hazardous materials and the necessary procedures to prevent and control spills and releases. Documentation of training will be retained with employee training records. 6.5 Maintenance Inspection, testing, and servicing of the chlorine system will be conducted annually by trained personnel. The main focus of annual maintenance is to ensure the system operates properly throughout the year. Inspections prior to use on a daily basis is also conducted. Maintenance personnel shall look for evidence of: * deterioration or corrosion which could threaten the integrity of the equipment * damage, such as dents or cracks, which could threaten the integrity of the equipment * gas leaks from valves and other fittings * malfunction of pumps, valves, the vaporizer, instrumentation, and safety equipment Inspections of the system will be documented on an inspection form and retained for at least five years. 6.6 Compliance Audits Lakeville WTP shall conduct a compliance audit of the chlorine system and certify tha t they have evaluated compliance with RMP provisions at least once every three (3) years. The intent of the audit program is to determine the effectiveness of the RMP and to identify any deficiencies that could lead to a release. The compliance audit will be conducted to check each element of the RMP program. In addition, the RMP will be amended in accordance with the guidelines and regulations whenever there is a change in the facility which affects the potential for releases to occur. These changes would include addition or deletion of tanks, equipment, or piping. At least one member of the audit team will need to be knowledgeable about the process. Lakeville WTP will prepare a written report of the compliance audit findings and retain the two (2) most recent reports on file. These records shall be retained for at least five (5) years after the audit was conducted. An compliance audit procedure and checklist is included in the appendix of the written report. 6.7 Inciden t Investigation Lakeville WTP understands the importance of an incident investigation to determine the root cause of an incident. Identifying the root causes of an incident will help to reduce and prevent injuries associated with a release of chlorine. In addition to any actual release, Lakeville WTP will investigate near releases involving the chlorine system. In the event of a release or near release, Lakeville WTP will assemble an investigation team as soon as possible to determine the root cause associated with the incident. Outside contractors will be involved if they were associated with an incident. An incident investigation checklist is included in the appendix of the written report. 7.0 Emergency Response Program Lakeville WTP has developed a comprehensive emergency response program to deal with plant emergencies. The Emergency Action Plan details programs developed for medical, severe weather, plant evacuation, fire, chemical release, and bomb threat emergencies. The local community response agency is the City of Lakeville Fire Department. In the event of a chemical release, they will be immediately contacted for assistance. Additional resources are also available from nearby communities as well as the Minnesota Emergency Response Commission. 8.0 Summary of Periodic Compliance Requirements A summary of periodic compliance requirements for Lakeville WTP's RMP program is shown in Table 1 below. Table 1 Summary of Periodic Compliance Requirements Program Element Frequency of Review or Updates Date of Previous Review or Updates Data Elements Major changes or every 5 years Off-Site Consequence Analysis Major changes or every 5 years Safety Information Major changes Hazard Review Major changes or every 5 years Operating Procedures Major change or as needed Maintenance Annually Training Annually Compliance Audit Every 3 years Incident Investigation As needed Emergency Response Plan As needed Lakeville WTP will p erform the required review and updates as required in the RMP rule. A copy of the RMP regulation is included in the appendix of the written report. 9.0 Community Relations and Public Information In conformance with 40 CFR 68, Lakeville WTP has prepared this RMP as part of its ongoing commitment to protect health and safety of employees and the public. It is the goal of Lakeville WTP to develop and build a relationship with the community and build trust among the public, neighbors, and the community at large. As part of its company objectives, Lakeville WTP intends to take its place as a good citizen in the community. Lakeville WTP believes that the Company and each individual employee have a responsibility to the communities where they work and live. In this regard, Lakeville WTP encourages employee involvement in the community, and both employee and Company support of local charitable organizations. Finally, Lakeville WTP and community both have an interest to maintain an atmosp here of open relations. This section is intended to answer commonly asked questions about this RMP for Lakeville WTP. Frequently asked questions: What is the difference between hazard and risk? Hazards are inherent properties that cannot be changed. Chlorine is toxic and can lead to a respiratory irritation if released in sufficient quantities. Chlorine is a gas at ambient conditions. Therefore, it is normally stored as a pressurized liquid. Being heavier that air, it can collect in low places and displace oxygen. There is nothing that can be done to change the properties of chlorine. Another example of hazard is from the natural causes, such as severe weather, floods or earthquakes. Risk is usually evaluated based on several variables, including the likelihood of the release occurring, the inherent hazards of the chemical and the quantity released, and the potential impact of the release on the public and the environment. For example, if a release occurs during loading a nd the quantity of release is small and does not migrate offsite, the overall risk to the public is low. If the likelihood of a catastrophic release is extremely low, but the number of people who could be affected is large, the overall risk may still be low because of the low probability that a release will occur. What does the Worst-Case Release Distance Mean? The worst case distance is intended to provide an estimate of the maximum possible area that might be affected under catastrophic conditions. It is intended to ensure that no potential risks to public health are overlooked, but the distance to an endpoint under worst-case conditions should not be considered a "public danger zone". In most cases, the models used to determine the extent of a worst-case release scenario may overestimate the area that would be impacted by a release. For great distances from the site, the models are especially uncertain. The models do not incorporate site-specific factors, such as buildings o r berms located between the source and the public. These obstacles could mitigate and reduce the area of impact, if a worst-case release should occur. If there is an accident, will everyone within 0.9 miles be hurt? In general, no. For a flammable release, everyone with the circle would certainly feel the blast wave since it would move in all directions at once. However, while some people within the circle could be hurt, it is unlikely that everyone would be since some people would probably be in less vulnerable locations. Most injuries would probably be due to flying glass, falling debris, or impact with nearby objects. Generally, it is the people closest to the facility who would face the greatest danger if an accident occurred. In an explosion, environmental impacts and property damage may extend beyond the distances at which injuries could occur. For toxic chemicals, whether someone is hurt by a release depends on many factors. First, the released chemicals would usually move in the direction of the wind (except for some dense gases, which may be constrained by terrain features to flow in a different direction). Generally, only people downwind from the facility would be at risk of exposure if a release occurred, and this is normally only a part of the population inside the circle. If the wind speed is moderate, the chemicals would disperse quickly, and people would be exposed to lower levels of the chemical. If the release is stopped quickly, they might be exposed for a very short period of time, which is less likely to cause injury. However, if the wind speed is low or the release continues for a long time, exposure levels will be higher and more dangerous. The population at risk would be a larger proportion of the total population inside the circle. Generally, it is the people who are closest to the facility who would face the greatest danger is an accident occurred. Damage to property and the environment will depend on the type of chemical released. In an explosion, environmental impacts and property damage may extend beyond the distance at which injuries could occur. For a vapor release, environmental effects and property damage may occur as a result of the reactivity or corrosivity of the chemical or toxic contamination. (Excerpt from the Risk Management Program Guidance for Wastewater Treatment Plants) How sure are you of your distances? The distances determined in this RMP were based on conservative estimates which would tend to overestimate the impact area from a catastrophic release. The model represents scientist's best efforts to account for all variables involved in an accidental release. No model is perfect and different models can produce differing results. Lakeville WTP has used the guidance established by EPA (EPA*Comp) to represent a worst case situation for a chlorine release. Lakeville WTP believes that using a conservative approach yields conservative (overestimate) results for the distances that would occur from a worst-case release. Lakeville WTP recognizes that within the predicted distance is a band of uncertainty, and in the unlikely event of a catastrophic release, the extent of impact may be shorter or longer depending upon the conditions at the time of release. Do you need to store 5 one-ton containers on-site? Lakeville WTP has determined that storing a maximum of 5 one ton containers at the facility is the best balance between maintaining operations at the facility and public safety. Alternatives to storing the tone containers on site would be shipment of chlorine more frequently. An increase frequency of chlorine shipments increases the risk for on-road accidents and as well as handling accidents during delivery of the chlorine. The amount of chlorine stored at Lakeville WTP is sufficient to last approximately one month or so. The usage is dependent upon the municipal demands. What are you doing to prevent releases? Lakeville WTP believes that the s afety of its employees and community are of primary importance. Lakeville WTP is committed to developing and implementing safe work practices and procedures, and to maintain equipment in a safe condition. Lakeville WTP is also committed to providing training to employees to enable then to work and prevent accidents from occurring. Employees are trained and instructed to comply with all safety rules, regulations, and procedures. In addition to proper training of employees, supervisors and managers are responsible for managing emergency response actions and procedures. Supervisors and managers will be accountable for actively supporting and participating in the RMP program, including communication of, compliance with, and monitoring of safety performance. What are you doing to prepare for releases? Lakeville WTP believes that it is important to prevent releases through proper procedures and handling of chlorine. In the event of a release, Lakeville WTP has developed procedures and contingencies to respond. Employees have been trained to properly respond to releases of chlorine to protect themselves, other employees, and the public. In the event of a release that is beyond the control, or presents and unacceptable risk to employees, the City of Lakeville Fire Department may respond to the emergency. The Lakeville Fire Department will implement their incident command system to manage the emergency response and request additional assistance, if necessary. How likely are the worst-case and alternative release scenarios? It is generally not possible to provide accurate numerical estimates of how likely these scenarios are. EPA has stated that providing such numbers for accident scenarios rarely is feasible because the data needed (e.g. rates for equipment failure and human error) are not usually available. Even when data are available, there are large uncertainties in applying the data because each facility's situation is unique. In general, the worst-cas e scenario is low. Although catastrophic vessel failures have occurred, they are rare events. The alternative scenario, although more likely, is also believed to occur very rarely. Lakeville WTP is committed to developing and maintaining safe work practices and procedures, to maintain equipment in a safe condition. Lakeville WTP is also committed to providing training to employees to enable then to work and prevent accidents from occurring. Employees are trained and instructed to comply with all safety rules, regulations, and procedures. As evidence of Lakeville WTP's committed adherence to safe work practices and procedures, the chlorine system has not experienced a reportable release or incident since Lakeville WTP obtained ownership of the site in 1997. Is the worst-case release scenario you reported really the worst accident you can have? EPA defined a specific scenario (failure or the single largest vessel) to provide a common basis of comparison among facilities nationwide . Lakeville WTP stores a maximum of five one-ton 2,000 pounds each) containers of chlorine. The absolute worst scenario would occur if the entire contents of one tank was released resulting in a toxic cloud. The chlorine containers stored at the Lakeville WTP are self contained and not interconnected. It should be noted that the relationship between the quantity of toxics released and the distance to the endpoint are not directly proportional. Thus, doubling the release quantity does not double the distance to the endpoint. Lakeville WTP has determined that such a release would be extremely unlikely and the worst-case release from a single vessel was appropriate. An event that may result in the complete release of chlorine from multiple vessels would most likely involve a disaster, such as a tornado, that completely destroys the facility. If this occurred, the effects of the natural disaster would make modeling the release nearly impossible and certainly very inaccurate. In this case, the primary and secondary effects of a tornado and response requirements to the citizens in the area would be the primary concern. Risk Management Plan: Lakeville Water Treatment Plant June, 1999 12 15 |