City of Bedford Waste Water Treatment Plant - Executive Summary

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1.0 SOURCE & SUBSTANCE 
 
The City of Bedford Wastewater Treatment plant treats 1.2 million gallons of sewage from the City of Bedford each day.  It discharges treated wastewater into the Little Otter River. 
 
In order to remove harmful pathogens from wastewater before it is released into the Little Otter River, the plant chlorinates wastewater in the final steps of treatment.  Then, to prevent damage to the river ecosystem from excess chlorine, the plant uses sulfur dioxide to remove chlorine before the water is discharged.  For these processes, chlorine and sulfur dioxide are separately stored on site as gases that have been pressurized to form a liquid. 
 
Chlorine is a water-soluble, poisonous gas that is highly irritating to the respiratory organs.  At concentrations of 15 parts per million (ppm), chlorine is immediately irritating to humans by inhalation.  At concentrations of 50 ppm, chlorine is dangerous even for brief exposures, and exposures of 1,000 ppm may be fatal even if expo 
sure is brief.  Long term damage from chlorine gas exposure includes changes in the trachea, bronchi, emphysema, and congestion in the respiratory system.  Short-term effects include coughing, vomiting, headache, and chest pains.  However, the human olfactory sense can detect chlorine concentrations as low as 3.5 ppm, so extensive exposure rarely occurs. 
 
Sulfur dioxide is a colorless, nonflammable, water-soluble, suffocating gas, which is known to be a dangerous air pollutant because of its corrosive properties.  Sulfur dioxide irritates the eyes, skin and respiratory system.  Due to these potentially serious health consequences, full measures are taken to prevent an accidental release of either chlorine or sulfur dioxide.   
 
 
2.0 ACCIDENT HISTORY & ACCIDENTAL RELEASE PREVENTION PROGRAM 
 
The City of Bedford Wastewater Treatment Plant can certify that there have been no releases of chlorine or sulfur dioxide that have resulted in any off site impact in the past five years.  However, th 
ere was a release of chlorine on March 19, 1998 that injured one employee.  The employee was treated at the hospital and released the same day.  There were no on-site or off-site damages from the release.  Since the accident, the plant has put into effect an extensive accidental release prevention program to improve its safety record.   
 
As an affected facility under Occupational Health and Safety Act Process Safety Management (OSHA PSM) requirements, the plant is a Program 3 participant.  The most extensive of the three RMP programs, Program 3 includes a number of requirements that closely track OSHA PSM requirements.  Program 3 also focuses on the off-site consequences of an accidental release.  The prevention program outlines information and procedures regarding all aspects of safe operation, including process safety information, Process Hazard Analysis (PHA), operating procedures, mechanical integrity, and personnel training.   
 
The PHA is designed to be conducted by a cross-secti 
on of facility employees, with guidance from employees directly involved in the chlorine and sulfur dioxide processes.  The PHA team identifies, evaluates, and implements controls associated with hazards in the chlorine and sulfur dioxide processes.  The overall purpose of the PHA is to comply with the PSM/RMProgram regulations and to prevent or minimize the effects of a chemical release.  The PHA team may conduct a new hazard analysis if significant modifications have been made to the current process or new regulated processes are added.  PHAs are, however, updated and revalidated at least every five years after completion of initial PHAs. 
 
The program also ensures that the plant maintains up-to-date, accurate, written Operating Procedures that provide clear instructions for all covered processes.  Effective operating procedures, when combined with operator training, are instrumental in guaranteeing safe operation of the systems and preventing accidental releases.     
 
The mechanical int 
egrity program is integral in preventing accidental chemical releases that may result from mechanical failure of improperly maintained equipment.  This program outlines equipment maintenance procedures, including maintenance, testing, and inspection schedules and procedures, maintenance personnel training, correction of equipment deficiencies, and quality assurance of new equipment. 
 
Finally, personnel training practices ensure that all employees, including maintenance and contract employees, working on or near the chlorine and sulfur dioxide process fully understand the processes and safety measures necessary for correct operation.  All personnel currently working at the plant have been certified as having all of the required knowledge, skills, and abilities to conduct their jobs safely and efficiently.  In addition, the plant will train and certify new personnel and conduct mandatory refresher courses for all personnel.  
 
 
3.0 EMERGENCY RESPONSE PROGRAM 
 
40 CFR Part 68.90(b) states t 
hat Athe owner or operator of stationary source whose employees will not respond to accidental releases of regulated substances need not comply with section 68.95 of this part provided that they meet the following:  (1) For stationary sources with any regulated toxic substance held in a process above the threshold quantity, the stationary source is included in the community emergency response plan developed under 42 U.S.C. 11003;@.  Since the policy of the City of Bedford Wastewater Treatment Plant is to allow the emergency response teams organized by the City of Bedford LEPC to respond to emergencies at the plant, the City of Bedford Wastewater Treatment Plant is not required to comply with 40 CFR Part 68.95, pertaining to the development and implementation of an emergency response program.  However, the plant has in place and trains all employees in emergency procedures regarding safe evacuation of the plant in emergency situations.   
 
 
4.0 NOTES 
Several pieces of equipment are in th 
e process of being replaced.  The replacement equipment will function the same as the current equipment, and all operations and maintenance manuals, critical equipment lists, etc. that are affected by the change will be updated as appropriate.  The replacements will not require a change in the off-site consequence analysis, PHA, or the program level.
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