Casitas #2 Chlorination Station - Executive Summary

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                         EXECUTIVE SUMMARY 
    The objectives of Casitas' accidental release prevention and emergency response 
 policies are to prevent unwanted releases of chlorine gas which could expose employees 
 and the public to serious hazards.  Casitas' policies include review and controls on process 
 design, operation and maintenance activities and procedures, emergency preparedness 
 plans and training programs. 
    Casitas' approach to safety as stated in the company Injury and Illness Prevention 
 Program is as follows: 
    It is the policy of Casitas Municipal Water District to strive for the highest safety and 
 health standards on all projects and work assignments.  Safety is the result of careful 
 attention to all District policies and procedures by all employees and management 
    Our safety program has been developed to assure compliance with federal, state, 
 and local regulations, with emphasis on t 
he occupational safety and health act of 1970.  We 
 intend to prevent any human suffering as a result of accidents.  Prevention of injury is a goal 
 well worthy of our concern, diligence and job performance. 
    Our employees have the right to a safe and healthful work environment.  They also 
 share the responsibility of working and acting in a safe manner.  Our safety policy can be 
 summarized into one sentence: 
                   "If it can't be done safely, 
                   we don't want you to do it." 
    Casitas' three chlorination stations use chlorine gas liquefied under pressure to 
 disinfect the community's water supply.  Chlorine gas is drawn through piping under 
 vacuum to injectors where the chlorine gas is mixed with water and then the solution is 
 pumped into the pipeline.  The locations of the chlorination stations are as follows: 
    Casitas #1 - The chlorination station located at the base of Casitas Dam is used to 
 inject chlorine into the p 
ipeline supplying Casitas' distribution system.  Chlorine is brought 
 to the site in one-ton containers.  Six of these one-ton containers are connected to the 
 dispensing system at any one time. 
    Casitas #2 - The chlorination station located on the west side of Casitas Vista Road 
 approximately .75 miles southeast of Casitas Dam.  The facility is used to inject chlorine 
 into the pipeline supplying Casitas' distribution system.  Chlorine is brought to the facility in 
 one-ton containers.  Two of these one-ton containers are connected to the dispensing 
 system at any one time. 
    Rincon - The chlorination station located on the south side of Casitas Pass Road, 
 approximately 0.9 miles west of Casitas Lake.  The station is used to inject chlorine into the 
 pipeline supplying the District's Rincon distribution system.  Chlorine is brought to the 
 facility in one-ton containers.  One of the one-ton containers is connected to the dispensing 
 system at any one time. 
    The USEPA Risk Management Program (RMP) regulations require facilities with a 
 regulated substance above the listed threshold quantities to prepare a formal Risk 
 Management Program and submit a Risk Management Plan.  The RMP consists of three 
 major components; a hazard assessment, a prevention program and an emergency action 
 plan.  Additionally Casitas is subject to OSHA Process safety management and emergency 
 action plan regulations, and State EPCRA laws. 
    The hazard assessment portion of the RMP consists of assessment of hypothetical 
 and alternative scenarios for the release of chlorine.  The assessment includes dispersion 
 modeling, identification of the area where chlorine gas levels can be above specified toxic 
 end point criteria, and estimating potentially affected populations or sensitive environmental 
 areas.  To state it in simpler terms, the hazard assessment estimates the area of the 
 downwind chlorine gas migration in the event of an accidental r 
elease from a chlorination 
 facility.  The hazard assessment was done for Casitas by an experienced consultant 
 (Kazarians & Associates).  The stream-valley topography surrounding Casitas #1 and #2 
 chlorination stations does not directly correspond to the "rural" or "urban" designations that 
 are used for modeling purposes.  Rural topography is characterized by a lack of buildings 
 or obstacles that would create air turbulence and mixing. Urban topography is 
 characterized by buildings or other obstacles (trees) that create turbulence and increase air 
 movement.  This increases atmospheric mixing and results in the computation of a lower 
 distance to toxic endpoint for a given release than rural topography would.  In Casitas' 
 situation, the trees and other obstacles increase air turbulence and mixing, but the stream 
 valley could confine a chlorine gas release and direct the release cloud downhill.  For this 
 reason, rural distances to endpoint were used instead of the rel 
atively lower urban 
 distances when calculating the area of down wind gas migration. 
    The required worst case release scenario is extremely unlikely due to the fact 
 that it specifies using the maximum amount of chlorine contained in one cylinder 
 (2000 lbs) to be released during a ten minute period.  The most likely cause for a 
 release of this magnitude would be a catastrophic event.  Regulatory agencies 
 recognize that the worst case scenario may represent a highly improbable scenario 
 which may not be appropriate for emergency planning.  The alternative scenarios 
 are those that are more credible and more appropriate for emergency planning. 
 The one-ton containers are stored in an enclosed building that would slow down the 
 release of chlorine gas.  The estimated distance of toxic levels of chlorine gas from 
 the chlorination stations was calculated from the EPA Risk Management Program 
 Guidance for Wastewater Treatment Plants. 
    The alternative scenario is 
also unlikely, but more likely to occur than the 
 worst case, because the alternative scenario can be based on an equipment failure.  
 The intent is to select a credible scenario that provides a basis for planning on-site 
 emergency response and off-site community response.  The alternative scenario 
 chosen for this analysis is the failure of the lowest fusible plug on the chlorine 
 cylinder, causing the release of liquid chlorine into the chlorination room.  This 
 scenario was chosen because it would result in a larger release quantity than a 
 chlorine gas leak near the top of the cylinder.  It is unlikely that a leak towards the 
 top of the cylinder would release the full amount in the cylinder.  The reason being 
 that if a leak occurs above the liquid level in a pressurized cylinder, the chemical 
 properties of chlorine (high vapor pressure and low boiling point) will cause frost to 
 form on the vessel in the area of the leak forming a barrier that stops the 
on.  Another safety feature that minimizes the likelihood of a major release 
 is that the chlorine gas piping from the cylinders to the injectors is operated under 
 vacuum. The chlorine injectors operate using the venturi principle, which generates 
 a vacuum in the chlorine gas line; this vacuum opens the valve to the chlorine 
 container, and allows the gas to flow.  Additional manual valves are used as flow 
 regulators.  If vacuum is lost (piping damage) the vacuum actuated flow valve will 
 close and this will stop the gas flow and isolate the chlorine container.  To further 
 enhance safety, the chlorination facilities are enclosed in concrete block buildings 
 that would slow the release of chlorine to the surrounding environment.  This is 
 termed passive mitigation, and was accounted for when calculating release 
 scenarios.  Offsite impacts were predicted from both the worst case and alternative 
 release scenarios. 
    To ensure an immediate response by district person 
nel to a chlorine release, 
 a chlorine gas detector is located inside of each chlorination station.  Should a 
 chlorine release occur, the gas detector immediately initiates an audible alarm and 
 warning beacon at the chlorine station.   Alarms are also actuated at the nearby 
 treatment plant at Casitas dam and at the district office in Oak View, and an on-call 
 operator who is available 24 hours a day is paged. 
    The emergency warning system is tested by District technicians once a 
 month.  The warning system is on an emergency back-up generator in the event of a 
 power loss.  All equipment used for dispensing chlorine receives a preventative 
 maintenance overhaul every year. 
 The second major component of the RMP is the prevention program.  The goal of the 
 prevention program is to reduce the risk injury or death to employees and the public 
 from accidental release of chemicals.  The prevention program consists of the 
 following elements: 
of process safety information for the chlorination process at 
      the three sites.  Process safety information assists the employees in 
      understanding the chlorination process so that they can operate in a safe and 
      efficient manner. 
    A  Process Hazard Analysis has been done to identify potential hazard and 
      operability concerns.   The Process Hazard Analysis contains 
      recommendations to reduce the risk of potential hazards or accidental 
      releases, and to comply with the regulations. 
     Casitas maintains current and accurate operating procedures that provide 
      clear instructions for the chlorination process.  Operating procedures when 
      combined with operator training ensure safe operation of the chlorination 
      process and prevent accidental releases. 
    The Casitas training program ensures that personnel are adequately trained 
      and understand inherent hazards and appropriate response actions to 
chemical releases. 
    The mechanical integrity program ensures the continued integrity of the 
      chlorination process equipment. This program is integral to the prevention of 
      accidental chemical releases that may result from mechanical failure of 
      improperly maintained equipment. 
    The management of change procedure ensures that chlorine system changes 
      are properly reviewed against original system design specifications.  It 
      ensures that changes can be accomplished safely and that systems are ready 
      to operate safely in accordance with original system design intent following 
      implementation of the change. 
    Prestartup reviews will be performed when modification of the chlorination 
      process is significant enough to require a change in the process safety 
      information.  Prestartup reviews ensure that Casitas is ready to safely operate 
      new and modified chlorination processes. 
    Compliance audits will be per 
formed to process safety and risk management 
      programs and their implementation for OSHA PSM and EPA RMP regulations.  
      Whenever necessary the, audit will identify recommendations to address 
      program deficiencies. 
    All incidents at the Chlorination facilities which could have resulted in or 
      reasonably resulted in a release of chlorine, will be promptly investigated.  
      The purpose of the investigation is to identify the underlying causes of an 
      incident and to implement corrective actions to prevent the incident from 
    Casitas recognizes that it is essential to have it's employees involved in the 
      development and implementation of an OSHA PSM and EPA RMProgram.  
      The employee recognition program defines how the employees will be 
    The hot work permit procedure insures that a hot work permit will be required 
      for all hot work operations (welding, torch cutting etc.) conducted on 
or near 
      the chlorination processes. 
    Only contractors with good health and safety programs will be selected to 
      perform work on or around the chlorination process.  The contractors and the 
      chlorination process must be properly prepared to safely complete the work. 
    The management system ensures that everyone who is involved with the 
      RMProgram understands their roles and responsibilities and that 
      responsibilities are assigned for all of the program elements. 
 The third major component of the RMP is the Emergency Action Plan.  The purpose 
 of Casitas' Emergency Action Plan is to minimize the duration and effects of an 
 accidental release of chlorine.  For minor releases where there is clearly no potential 
 for safety or health hazard, the release will be controlled by the employees and will 
 be considered an incidental release.  If a release is progressing so that a hazard is 
 imminent, the event must be considered a release and t 
he Emergency Action Plan 
 will be initiated.  The Emergency Action Plan includes Casitas in the community 
 emergency response plan, and specifies the appropriate mechanisms for notifying 
 emergency responders.  The Emergency Action Plan includes specific actions to be 
 taken in response to releases of chlorine such as notification of the Plant Supervisor 
 or Chief Operator, and notification to the Office of Emergency services (OES).  OES 
 will in turn notify the County of Ventura Environmental Health Department.  If it 
 becomes necessary, Ventura County Fire Department and Ventura County Sheriffs 
 Office will be notified to handle evacuations, but during an extreme emergency 
 saving lives is more important than procedure. 
 Casitas is pleased to report that at all three chlorination Stations there have not 
 been any events during the previous five years that had any potential for generating 
 a significant accidental release.  Addressing the recommendations developed from 
 the Process Hazard Analysis is the top priority for planned changes to improve 
 safety in the near future.  Casitas will continue its policy to address and review all 
 safety concerns as necessary.  The Risk Management Plan will be updated and 
 resubmitted as required by the regulations. 
 to Toxic 
 within the 
 Casitas #1 
 Worst Case 
 2.25 miles 
 0.4 miles 
 -Lake Casitas Recreation 
 Area -Foster County Park 
 Casitas #2 
 Worst Case 
 2.25 miles 
 0.4 miles 
 -Lake Casitas Recreation 
 Area -Foster County Park 
 Worst Case 
 2.25 miles 
 0.4 miles 
 Los Padres 
 Los Padres Nation Forest
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