BSU Water Treatment Plant - Executive Summary
EXECUTIVE SUMMARY |
Bonita Springs Utilities Water Treatment Plant
Introduction and Background
The USEPA's Clean Air Act Amendments of 1990 included provisions that require facilities that use certain substances to develop a plan to reduce the likelihood of an accidental release of the substances to the atmosphere and reduce the likelihood of serious harm to the public and the environment. The plan must also include mitigation measures to reduce the potential impact on the public in the unlikely event of a release. The requirements of this plan, commonly referred to as a Risk Management Plan (RMP), are detailed and codified in 40 CFR Part 68.
Bonita Springs Utilities, Inc. (BSU) operates one water treatment plant: the BSU Water Treatment Plant (WTP). This facility stores chlorine in quantities above the regulatory thresholds at which a RMP/PSM is required. Ammonia is not currently stored in quantities above the RMP/PSM regulatory thresholds. Currently, the BSU WTP stores approximate
ly 4550 lbs of ammonia on-site but will upgrade to 10,000 lbs in the near future. The RMP/PSM is being prepared assuming on-site storage of 10,000 lbs of ammonia as a proactive exercise. Chlorine and ammonia are used to disinfect the water prior to distribution.
The RMP/PSM consists of three compliance programs, each with progressively stricter compliance standards. The chlorination and ammoniation processes at the WTP are subject to Program 3, the most stringent of the three programs, because the plant is subject to the OSHA Process Safety Management (PSM) Standards and a worst-case release of chlorine or ammonia could affect the public.
The RMP/PSM consists of three major parts. The first part is the Hazard Assessment. The Hazard Assessment is done to determine the effects that a release of a regulated substance could have on the public. The second part is a Prevention Program that consists of 12 elements designed to improve the system safety and decrease the likelihood of a rele
ase. The third part is the Emergency Response Program, which develops a plan for dealing with a release in the unlikely event that one would occur. Because the regulations are very similar, the Prevention Program and the Emergency Response Program also serve as the OSHA PSM plan, and this document is therefore referred to as the RMP/PSM plan.
As part of the RMP, a submittal to the USEPA is required which is referred to as RMP/PSM Submit.
A Hazard Assessment was performed to determine the effects a release would have on the public. For chlorine and ammonia, the distance a set endpoint concentration of the gas would travel must be determined. In addition, an estimate of the population that could be affected by a release of chlorine or ammonia was determined and sensitive receptors such as hospitals, schools, and nursing homes were identified. The Hazard Assessment considers two release scenarios-a "worst case" and an "alternative case."
ulations require the development of a worst-case release scenario based on conservative assumptions. For example, it is required to assume that the entire contents of the largest single container of chlorine or ammonia will be released over 10 minutes. For the BSU WTP, it is assumed that an entire one-ton cylinder of chlorine is released over 10 minutes. For ammonia, future conditions are modeled with the assumption that an entire 10,000 pound vessel of ammonia is released over 10 minutes even though the plant currently stores less. For chlorine, this is unlikely to occur since the properties of chlorine would cause a freeze and thaw cycle to occur at the leak, which would slow the release. In addition, only "passive" mitigation methods such as buildings or dikes can be considered when determining the distance the release could travel. Passive mitigation, as defined, requires no mechanical, electrical, or human input. However, in many scenarios mitigating the release by isolating t
he process could reduce the amount released. In addition, the worst-case scenario requires that conservative atmospheric conditions be assumed which results in a large area of impact.
The hazard assessment requires that the "toxic endpoint" or distance from the point of release to a location at which the chemical concentration equals or exceeds a certain concentration be determined. That concentration is defined as the maximum airborne concentration below which individuals could be exposed for up to 1 hour without experiencing or developing irreversible or other serious health effects, or symptoms that could impair an individual's ability to take protective action. Because the cloud from a chlorine or ammonia leak would disperse relatively quickly, an individual at a toxic endpoint would be exposed to the exposure limit concentration for much less than the 1 hour assumed by the limit. In addition, the exposure limit concentrations result in relatively minor health effects. Therefore,
an individual at the toxic endpoint would be affected less than the results of the worst-case scenario may imply.
The model used for the worst-case scenario for chlorine determined the distance at which the chemical's concentration was 3 ppm or greater (the toxic endpoint for chlorine). Based upon the model results, the worst-case scenario distance was determined to be 1.02 miles. The model used for the worst-case scenario for ammonia determined the distance at which the chemical's concentration was 200 ppm or greater (the toxic endpoint for ammonia). Based upon the model results, the worst-case scenario distance was determined to be 1.2 miles.
The RMP rule also requires that at least one alternative release scenario be evaluated for chlorine and ammonia. The alternative scenarios reflect a type of release that is more likely to occur compared to the worst-case scenario. Unlike the worst-case scenario, the alternative release scenario may consider "active" mi
tigation such as shutoff valves and a more realistic release quantity and release rate. Active mitigation is defined as requiring mechanical, electrical, or human input. Lastly, it assumes local, typical meteorology, which is more realistic than the conservative meteorological conditions that must be assumed for the worst-case scenario.
Two alternative release scenarios were investigated for chlorine at the BSU WTP. One alternative release scenario occurred through a vacuum regulator release and the other through a fusible plug rupture. The BSU WTP has an emergency chlorine scrubber with a capacity to neutralize the contents of a 1-ton chlorine cylinder with an efficiency of 99.9994 percent. The presence of the scrubber almost completely insures that any release would be contained on site. To model an off-site release as required by the USEPA, we must assume that there would be a scrubber failure during the alternate releases. In reality, the likelihood of an off-site release would
be very small as long as the scrubber is functional.
Two alternative release scenarios were also investigated for ammonia at the BSU WTP. One alternative release scenario occurred through a vessel pressure relief valve release and the other through a pipe corrosion leak. The alternative release scenario is considered to be more representative of the effects likely in the event of a release. The results of the alternative release scenarios are presented in Table 1 below.
Table 1 Bonita Springs Utilities Results of Alternative Release Scenarios
Chemical/Scenario Toxic Endpoint (miles)
Vacuum regulator release 0.10
Fusible plug rupture 0.40
Pressure relief valve release 0.10
Pipe corrosion leak 0.10
The Prevention Program, together with the Emergency Response Program and Hazard Assessment, make up the RMP/PSM. T
he Prevention Program consists of 12 elements designed to improve the system safety and decrease the likelihood of a release.
The participation of the BSU WTP staff in preparing the RMP/PSM program was critical to the program's successful implementation. Employee participation is valuable because it increases the safety awareness of the staff and it allows the staff's experience in operating and maintaining the processes to be incorporated into the plan.
WTP staff participated in the development of the Prevention Program through a series of meetings, as well as the Process Hazard Analysis described below. All WTP staff received awareness training that instructed staff on how the RMP/PSM requirements may impact their jobs, an overview of each of the RMP/PSM plan elements and the procedures that must be followed to comply with the requirements of the RMP/PSM plan.
Process Safety Information
The RMP regulations require that information concerning process chemic
als, technology, and equipment be compiled as part of an RMP program. Emergency response planners can use such information to develop training programs and procedures, or as a general resource. The information will be supplied to contractors who will work in the chlorine or ammonia process area as part of the requirements outlined in the Contractors element. All the required process safety information was compiled as required by the RMP regulations. The information meets and in many cases exceeds the minimum required by the regulations.
Process Hazard Analysis
A process hazard analysis (PHA) was conducted to evaluate potential causes and consequences of accidental releases. This information was used by WTP staff to improve safety and reduce the consequences of accidental releases. Equipment, instrumentation, utilities, human actions, and external factors that might affect the process were the focus of the PHA.
A Process Hazard Analysis team was assembled at Bonita Springs Utilities
. The chlorine and ammonia PHAs were conducted by a team of BSU staff familiar with the process operation and maintenance and facility management. The PHA team has expertise in engineering, chlorine and ammonia process and operation and chlorine and ammonia process hazard analysis methodology.
The PHA was done using a combination of "What-If" and "Checklist" methods. Based on the results of the PHA, changes in operating, maintenance, and other process safety management procedures that would improve the overall safety of the WTP were identified. The changes that most affect the severity and likelihood of a release have been adopted by the plant and incorporated as part of the overall Process Safety Management Program. Other improvements and process modifications to reduce or eliminate potential hazards are scheduled to be implemented or incorporated.
Operating procedures for the chlorination process have been developed as part of the RMP/PSM. Written operating
procedures assure continuous, efficient, and safe operation of the WTP. The goal of the operating procedures is to provide clear instructions to safely operate the process. Operating procedures are also used to train new employees and to provide refresher training for existing staff.
The detailed operating procedures include startup, shutdown and emergency operating procedures. The procedures describe how the system should be operated in order to minimize the chances of an accidental release. The procedures also emphasize safety considerations during operation and address hazardous situations that can occur and how to correct them.
An effective RMP/PSM training program can significantly reduce the number and severity of accidental releases. Employees involved in operating or maintaining the chlorination process must receive training that includes applicable operating and maintenance procedures and an overview of the process. Training must emphasize safety and health hazards
and safe work practices.
BSU WTP staff have received initial training on the operations and maintenance of the regulated processes through on-the-job training. Staff who operate and maintain the RMP/PSM processes were trained how to safely maintain and operate the processes. BSU certifies each of the Water Plant Operators and Maintenance personnel on the safe handling of chlorine and emergency response annually. BSU gives biennial training on equipment lock-out/tag-out procedures, confined space entry procedures and hot work permit procedures.
The BSU WTP must make contractors aware of the known hazards of the chlorine and ammonia process related to the contractors' work. In addition, the WTP must make contractors aware of the applicable elements of its emergency response plan. BSU should screen for contractors that can perform work on or adjacent to the chlorine or ammonia process without compromising the safety and health of employees at the plant.
BSU must obta
in and evaluate information regarding the contractor's safety performance and programs before allowing a contractor to work on or adjacent to the chlorine process. When a contract involving work on or adjacent to the chlorine or ammonia process is to be bid, the bidding procedures must ensure that contractor safety management requirements are met. To make the contractor aware of the WTP RMP/PSM plan requirements, a safety briefing must be conducted before work begins in or adjacent to any covered process. Upon arriving at the plant for the first time to perform work, the contractor is presented with a Contractor Safety Management Briefing Form that must be read and signed.
A pre-startup safety review must be conducted for any new covered process or for significant modifications to the existing chlorine or ammonia process that necessitate a change in the process safety information. No new or significantly modified process will start up and no acutely hazardous che
micals will be introduced into such a process prior to the pre-startup safety review. The purpose of the pre-startup safety review is to ensure that the facility is ready to operate new and modified regulated processes safely.
To initiate the pre-startup safety review, all updated elements of the Process Safety Management Plan are assembled for review. This includes all process safety information, process hazard analysis, operating procedures, employee training and mechanical integrity records. The pre-startup safety review team should complete and sign a Pre-startup Safety Review Form. This form documents the process, and helps ensure that the review has been properly performed. The Pre-startup Safety Review Form must be authorized before startup.
An effective mechanical integrity program is one of the primary lines of defense against a release. The mechanical integrity program addresses equipment testing and inspection, preventive maintenance schedules, and p
ersonnel training. The intent is to ensure that equipment used to process, store, or handle chlorine or ammonia is maintained and installed to minimize the risk of releases.
The BSU WTP maintenance staff has a mechanical integrity program that includes equipment and instrumentation identification, maintenance, testing and inspection schedules, personnel training and maintenance documentation. Preventive maintenance is scheduled based on equipment manufacturers' recommendations published in their operation and maintenance (O&M) manuals. In addition to preventive maintenance, WTP staff performs corrective maintenance in the event of equipment malfunction or breakdown. Work orders indicate what safety precautions must be followed including whether lockout/tagout or confined space entry provisions are applicable.
Hot Work Permits
RMP/PSM regulations require employees and contractors to employ safe work practices when performing "hot work" in, on, or around the chlorine or ammonia proc
ess. To ensure that hot work is done safely, a Hot Work Permit Program has been developed that requires a permit to be issued before hot work is performed. Examples of such work include but are not limited to: welding, cutting, grinding, brazing and operating flame- or spark-producing operations.
The hot work permit requires the identification of hazards and appropriate safeguards, as well as the implementation of the safeguards to ensure a fire-safe workplace.
Management of Change
A system for the proper management of changes and modifications to equipment, procedures, chemicals, and processing conditions is required under the RMP/PSM. Modifications to the chlorine and ammonia system will be reviewed before they are implemented to determine if the modification would compromise system safety. An effective change management system will help minimize the chance for an accidental release.
If a modification covered under RMP/PSM is made, its effects must be addressed, employees must b
e informed, and the written procedures must be updated. The intent is to require that all modifications to equipment, procedures, and processing conditions other than "replacement in kind" be managed by identifying and reviewing them before implementation. A Management of Change Evaluation Form will be completed and evaluated for any modifications that are covered under the RMP/PSM. The Management of Change Form will be evaluated by the Operations Superintendent who will authorize the change prior to its initiation. A Notification of Process Change Checklist is also completed prior to system modification.
Each incident that resulted in or could reasonably have resulted in a catastrophic release (i.e. a release that results in death or permanent injury) of chlorine or ammonia must be investigated. A process to identify the underlying causes of incidents and to implement procedures for preventing similar events has been developed. To investigate an incident, an
Incident Investigation Review Team will be established. As part of the investigation, an Incident Report Form will be prepared to recommend system changes.
The investigation team should ask questions such as what equipment failed, which behavior failed, and which material leaked, reacted, or exploded? As part of the incident review, staff actions that may have contributed to the incident will also be reviewed. A determination will be made as to whether it is necessary to institute additional training for the employees to prevent the incident from occurring in the future. On the Incident Report Form, the Operations Superintendent identifies which of the recommended system changes are approved for implementation. The incident investigation report and any changes resulting from the report will be reviewed with all staff members who operate and maintain the applicable system.
The BSU WTP is required to complete a compliance audit for the RMP/PSM program. The primary go
als of conducting an internal compliance audit are to gather sufficient data to verify compliance with RMP/PSM requirements and good process safety practices, identify process safety deficiencies and develop corrective actions, and increase safety awareness among facility staff.
The compliance audit methodology is modeled after OSHA's guidelines for conducting regulatory PSM compliance audits: Compliance Guidelines and Enforcement Procedures, OSHA Instruction CPL 2-2.45A (September 28, 1995). An internal compliance audit must be conducted at the facility at least once every 3 years for the chlorine and ammonia process. A team that includes at least one person knowledgeable in the covered processes and an audit leader knowledgeable in RMP/PSM requirements and audit techniques will conduct the audits. The Operations Superintendent and the audit team will promptly determine an appropriate corrective action for each deficiency identified during the audit and document the corrective action
s and the dates by which they must be taken.
Emergency Response Program
The Emergency Response Program develops a plan for dealing with a chlorine or ammonia release. OSHA Process Safety Management regulation 29 CFR 1910.119(n) and EPA RMP regulation 40 CFR 68 Subpart E require that an Accidental Release Emergency Response Plan be prepared. The plan must be prepared in accordance with the provisions of another overlapping OSHA regulation-Employee Emergency Plans (29 CFR 1910.38(a)). In addition, provisions of the OSHA hazardous waste and emergency response standard, 29 CFR 1910.120 (q), must also be considered. The Emergency Planning and Response Plan described in this section complies with the requirements of 40 CFR 68.95, 29 CFR 1910.38(a), and 29 CFR 1910.120(q).
An Emergency Planning and Response Plan must be developed that provides employees with guidance on how to protect public health and the environment in case of a chemical discharge emergency. The emergency response proc
edures cover a release from the initial alarm stage through either leak stoppage or hazmat assistance. As part of the emergency response procedures there are plans for victim rescue, leak investigation, and communication with additional support agencies. In addition, critical plant operations are identified to insure that, if possible, the critical WTP functions are kept operational. The Emergency Planning and Response Plan also indicates the level of training needed to complete the emergency response procedures.
Information regarding self-contained breathing apparatus is also provided in the plan. It also addresses facility site communication, emergency response equipment, first aid and medical treatment, medical surveillance and consultation, and emergency response drills.
BSU has developed a comprehensive Emergency Response Program that fully satisfies RMP/PSM requirements. The procedures are outlined in the Chlorine Handling Plan. According to the plan, WTP personnel will only
respond to minor releases of chlorine or ammonia. In the event of a larger release, personnel will assemble at a designated location for evacuation of the facility after notifying the proper authorities (Bonita Springs Fire Department or Lee County HAZMAT team). Evacuation of areas surrounding the WTP, if necessary, is a responsibility of local police and fire departments.
The USEPA's Clean Air Act Amendments of 1990 included provisions that require facilities that use certain substances to develop a plan to reduce the likelihood of an accidental release of the substances to the atmosphere and reduce the likelihood of serious harm to the public and the environment.
Bonita Springs Utilities WTP staff participated in the development of the Prevention Program through a series of meetings. All the required process safety information was compiled as required by the RMP regulations. PHA information was used by WTP staff to improve safety and reduce the consequences of an a
ccidental release. Operating procedures for the chlorination and ammoniation processes have been developed. Staff have received initial training on the operations and maintenance of the regulated processes.
Additional RMP/PSM plan elements that have been completed include the development of a Contractor Safety Management Briefing Form, Hot Work Permit Program, Management of Change Evaluation Form, Incident Report Form, completion of a compliance audit and the performance of preventive and corrective maintenance. BSU has also developed a comprehensive Emergency Response Program that fully satisfies RMP/PSM requirements.
There were no reportable accidents at the BSU WTP between June 21, 1994, and the present date.