City of Bradenton Wastewater Treatment Plant - Executive Summary

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     THE CITY OF BRADENTON WASTEWATER TREATMENT FACILITY 
 
EXECUTIVE SUMMARY 
 
The City of Bradenton Wastewater Treatment Facility is a facility whose primary activity is the 
treatment of wastewater.  The Facility uses two regulated toxic substances at the Facility.  The first 
substance is chlorine (CAS 7782-50-5) which is used as a disinfectant to treat wastewater during the 
chlorination process.  The second substance is sulfur dioxide (CAS 7446-09-5) which is used during 
the dechlorination process to remove the residual chlorine from the effluent and maintain discharge 
compliance.   
 
The chlorination process consists of chlorine storage and the chlorination system used to disinfect 
the wastewater.  The chlorination process begins with the withdrawal of chlorine from the chlorine 
cylinders by a vacuum created by vacuum regulators mounted on the cylinders.  The chlorine gas 
travels through PVC pipes to chlorinators, where the chlorine supply is regulated and measured.  
From the chlorina 
tors, chlorine is mixed with reuse water by chlorine injectors to produce a solution 
which is injected into the effluent water for disinfection.  
 
The dechlorination process is similar to the chlorination process.  It consists of the sulfur dioxide 
storage and the dechlorination system.   Sulfur dioxide is withdrawn from the sulfur dioxide 
cylinders by a vacuum created by vacuum regulators, passed through PVC pipes to the sulfonators, 
finally to the sulfur dioxide injectors where sulfur dioxide in solution is injected into the chlorinated 
effluent.   
 
The hazard assessment was performed on the chlorination and dechlorination processes using the 
United States Environmental Protection Agency (USEPA) RMP*CompTM. Model.  The worst-case 
release scenario was assumed to be the release of a one ton cylinder  for a duration of 10 minutes in 
an enclosed building.  For this scenario, the off-site consequence analysis indicated that off-site 
receptors could be potentially impacted by the release o 
f chlorine or sulfur dioxide.  The alternative 
release scenario selected for the Facility was a failure scenario developed during the process hazard 
review and analysis.  The alternative release scenarios for chlorine and sulfur dioxide were similar.  
For each scenario, a 0.25-inch diameter whip connecting a one-ton cylinder to the process system 
manifold is sheared off, creating a leak in the system.  The Facility has the capability of responding 
to and stopping the leak within one hour of detection.   For this scenario, the off-site consequence 
analysis indicated that off-site receptors could be potentially impacted by the release of chlorine or 
sulfur dioxide. Although off-site areas would be impacted for the worst-case and alternative release 
scenarios, we believe that safety procedures and mitigation measures will reduce the potential for 
off-site consequences and subsequent risks to the surrounding community.  Our safety devices 
include chlorine leak detectors, sulfur dioxide lea 
k detectors, alarms, and an automatic system shut- 
off feature triggered by a loss in system vacuum.  In addition, the chlorine and sulfur dioxide 
cylinders are housed in a building with exhaust fans and vents which would dilute the chlorine and 
sulfur dioxide gas concentration should a release occur. 
 
In order to fulfill the requirements of the Risk Management Program (RMP), we have developed an 
accidental release prevention program and emergency action plan for our facility. The accidental 
release prevention program satisfies the requirements for the EPA RMP and the Occupational Safety 
and Health Administration's (OSHA) Process Safety Management (PSM) program.  The prevention 
program ensures that our facility is operated under safe conditions and that any risk of an accidental 
release of chlorine or sulfur dioxide is minimized.  The program has been written to reduce the 
potential of an accidental release due to human error, or equipment failure at our facility.  In order 
to prevent  
the release of chlorine or sulfur dioxide due to human error, our prevention program 
ensures that operating procedures are current and reviewed annually.  Training also plays a vital part 
in our program.  Employees and contractors working near or on the chlorination and dechlorination 
processes are required to be trained in the processes and the hazards of chlorine and sulfur dioxide.  
 
 
To prevent equipment failure that could result in an accidental release, our program ensures that 
equipment inspections, tests, and preventive maintenance in accordance with accepted engineering 
practices and includes manufacturer's recommendations.  All chlorine and sulfur dioxide cylinders 
are examined upon delivery and are rejected if there are any signs of damage.  In addition, equipment 
pertaining to the chlorine and sulfur dioxide processes are visually inspected daily.  The potential 
for a chlorine or sulfur dioxide release is greatly reduced in the chlorination and dechlorination 
processes due 
to the use of a vacuum system from the point of withdrawal to their points of 
application.  In the event that there is a failure in chlorination or dechlorination equipment, the 
system will automatically shutoff (i.e. failsafe).   
 
All existing and proposed future chlorination and dechlorination equipment have been designed 
according to applicable standards and codes.  The Facility maintains records and documentation on 
equipment inspection and tests.  Precautions are taken to ensure that new equipment and processes 
are inspected and tested, that all changes on the process are authorized, and employees are informed 
of changes. 
 
The Facility performed a Process Hazard Analysis (PHA) to address the hazards in the chlorination 
and dechlorination processes and to evaluate and control where the potential for chlorine and sulfur 
dioxide releases exist.  Employees were involved in determining hazards of the processes and 
subsequent consequences.  The chlorination and dechlorination processes 
were found to be operating 
safely and no changes were recommended.  
 
Active employee participation will ensure the success of the RMP at our facility.  Employees have 
been assigned various tasks to ensure that all elements of the RMP are implemented.  We have 
developed many different forms to assist employees in recording and documenting the various 
elements of the RMP.  
 
At the time of submittal of this Risk Management Plan, there have been no accidental releases of 
chlorine or sulfur dioxide at our facility in the past five years.  However, in the event that there is 
an accidental release of chlorine or sulfur dioxide, an Emergency Action Plan has been written in 
compliance with 29 CFR 1910.38.  The Facility is also included in the community emergency 
response plan.  Employees at our facility do not respond to accidental releases of chlorine and sulfur 
dioxide, but coordinate with outside responders.  Therefore, in accordance with 40 CFR 68.90, an 
Emergency Response Program is not 
required for our facility.  In the event that a chlorine or sulfur 
dioxide release occurs, all employees are required to evacuate the process area and report the 
incident.  The emergency action plan consists of evacuation procedures, facility emergency numbers, 
and coordination with the City of Bradenton Fire Department.  The plan also addresses notification 
procedures to the public and the local emergency response agency.    
 
We participated in the local Safety Street demonstration and are willing to conduct tours of our 
facility for members of the public.
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