Intermediate Pump Station Union Springs Wastewater - Executive Summary

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Union Springs WastewaterTreatment Plant - Intermediate Pump Station 
EPA ID: ALD983177916 
    The Union Springs Wastewater Treatment facility (Union Springs WWTP) utilizes an Intermediate Pump Station to provide Chlorination to finished wastewater before discharging it from the Plant.  Sewage is treated at the Union Springs WWTP from the nearby community of Union Springs, AL. The Union Springs WWTP consists of several wastewater treatment processes, including Chlorination, High Rate Trickling Filtration, Sedimentation and Biological oxidation. Treated water and sludge, following disinfecting with Chlorine, is then disposed of in accordance with State and Federal laws. 
    Chlorine gas has been in use for nearly a century as the choice disinfectant in the treatment of both sewage for discharge and surface and ground water for drinking.  Currently the Union Springs WWTP maintains a maximum inventory of 4,000 pounds of Chlorine gas.  Under EPA's Risk Management Program, Clean Air 
Act 112(r), any industry utilizing Chlorine, a regulated gas, above its threshold quantity of 2,500, must develop a Risk Management Plan and implement a Risk Management Program.   
    The Union Springs WWTP, in implementing their Risk Management Program (RMP), is currently undergoing changes in both process design and operations, as well as improving on their emergency response preparedness plans.  The Plant is currently prepared to respond to incidental leaks of Chlorine gas, and have on hand self-contained breathing equipment, a ton container repair kit, escape respirators, first aid stations, and fire extinguishers located throughout the facility.  Currently the Plant's Operators are furthering their training efforts by integrating Kit "B" repair training for the containment of controlled leaks from the one ton containers used for storing Chlorine during use. 
    In the spirit and law of the RMP, the Union Springs WWTP recognizes and is pursuing optimal public involvement in re 
sponse to regulated substance emergencies.  The Union Springs WWTP acknowledges that as a result of being in compliance with the RMP Rule, the safety of the surrounding community as well as that of on-site workers is significantly enhanced.  From improved record-keeping, training, and operating procedures to better engineering design, the Union Springs WWTP is dedicated to minimizing the risk of using Chlorine gas while at the same time improving the quality of local services.   
    Chlorine gas is required at the Union Springs WWTP for disinfecting sewage prior to final land disposal.  Chlorine gas is used as the principal disinfectant  The Union Springs WWTP recognizes that Chlorine gas, if accidentally released into the environment, may cause severe injury and even death for a significant distance from the source.  The Union Springs WWTP has recently adopted new emergency response policies, as well as maintenance and process guidelines under its RMP to prevent and prepare for the  
uncontrolled release of a regulated gas from the Plant.   
    The Union Springs WWTP  is currently owned and operated by the Union Springs Utility Board of Union Springs, AL, located approximately fifty miles east of Montgomery, AL.   The Intermediate Pump Station, which houses the ton containers of Chlorine gas, is overseen by the General Operations Manager, Mr. Joseph L. Davis (334) 738-3115.  The Chief Operator of the plant, Mr. Ronald W. Mills, will be the person who has the primary responsibility for the implementation of the RMP.  Mr. Mill's responsibility under the RMP will include the training and execution of the facility's safety, environmental  and emergency response programs.  Additional individuals may be assigned responsibility for implementing individual requirements and will report to Mr. Mills on delegated matters.  Responsible individuals will communicate information to other employees involved in operation and maintenance of the regulated process involving Chlorine 
gas, as required.  All responsible individuals so involved will be listed by name, title and duties, in the RMP located on site at this facility. 
   Any material changes in the design or maintenance [except for "replacements in kind"] of the current regulated process will be introduced into the RMP by those delegated that authority under the guidelines of the RMP.  The public may contact the Union Springs WWTP by calling (334) 738-5328 or the Union Springs Water Works & Sewer Board at ((334) 738-3115) for additional information regarding the Union Springs WWTP Risk Management Program. 
    The Union Springs WWTP currently maintains up-to-date safety information related to the regulated substance, process, and equipment, including Material Safety Data Sheets for Chlorine, maximum intended inventories, and safe upper and lower temperatures, pressures and process flows for the regulated substance.  Equipment specifications and process design Codes and Standards are also maintained in  
the RMP document on site.  
    In the case of an uncontrolled release of Chlorine or Sulfur dioxide gas from the Union Springs WWTP, an integrated Emergency Response Plan has been adopted involving the coordinated effort of several organizations, including the local Fire Department, Emergency Management Agency, Police, Sheriff's office and Medical Emergency services and Hospitals.  The Union Springs WWTP is prepared to assess and repair incidental or controlled leaks of the regulated materials but is currently not authorized to respond to uncontrolled releases of eChlorine from their facility.  Instead, the Union Springs WWTP has coordinated first response assistance from federally regulated Hazardous Materials (HazMat) specialists in adjoining counties.   
    Currently the Union Springs Fire Department cannot legally respond to an emergency requiring containment of Chlorine gas.  However, Level A suits and other equipment will be ordered.  Once the appropriate equipment arrives th 
e local Fire Department, under the direction of Mr. Tim Tompkin ((334) 738-4980)  will pursue certified HazMat status so that immediate responses can be made should an emergency involving the uncontrolled release of Chlorine does occur.  The Union Springs Fire Department is also planning to join the Plant's operators in Repair Kit "B" training to improve on emergency containment of Chlorine.  is currently up to date on HazMat training and will be qualified to serve as first responders once they have acquired the proper equipment.  For the next few months the Union Springs WWTP will continue to rely on emergency assistance from local volunteers and neighboring counties.  
    EPA requires each regulated facility to analyze a Worst-Case Scenario release for each of its regulated substances.  A Worst-Case Scenario is the release of the entire contents of a regulated substance container.  In addition EPA requires as well an Alternative-Case Scenario for each regulated substance in which t 
he released regulated gases are brought under control at some point following uncontrolled release events. 
    In the Worst-Case Scenario for Chlorine, detailed within the facility's RMP, a scenario is considered in which the uncontrolled release of the entire contents of a ton container of gas occurs.  There are no mitigation features included in these Worst-Case Scenarios, such as enclosed buildings or other structures.  The release is assumed to take place outside the Chlorine Building during an unloading event.  The endpoint radius for such a release, in which injury to those exposed is potentially possible, was calculated using parameters which are facility specific as well as criteria provided by EPA.  The endpoint radius was calculated to be 3.0 miles for Chlorine following the loss of the entire contents of a one ton container gas.  Close to the source of such a release the potential for serious injury is high.  
    The safety mechanisms in place at the Union Springs WWTP a 
re designed to prevent the Worst-Case scenario from occurring.  One of the principal mechanical lines of defense are the vacuum regulator valves on the ton containers of Chlorine. These valves release gas from the ton container only when a vacuum is applied, hence, if a line should break in the process manifold piping system for Chlorine, the regulator valves on the source will automatically shut off.  Other physical devices in place include detectors capable of setting off alarms when the atmospheric concentrations of Chlorine rise above 1 ppm, approximately that level which is detectable by humans. 
    Although the potential for an entire ton container of the gas to escape the Plant's boundaries is unlikely, it can happen.  The EPA requires all responders to such a release to coordinate with the local Emergency Management Agency, the Fire Department, HazMat specialists and other local authorities such as the Police Department and Sheriff's office, in order to effectuate the best pl 
an for evacuation efforts, if needed, and other requirements to assure the greatest protection for those who may be exposed to the gas.  As described below, recommendations have been submitted regarding improved maintenance and safety, the introduction of a community siren system, as well as initial response activities developed through coordinated efforts with the participating agencies and rescue organizations. 
    As part of the Worst-Case scenario Emergency Response Action the cooperating agencies considered, and is currently implementing, procedures for responding to sensitive receptors within the endpoint distance of the regulated gas.  For example, local Schools, Hospitals and other sensitive receptor sites are currently being integrated into the community's Emergency Response Plan through the efforts of the Fire Department, LEPC, Police Department and others.  Cooperative interaction between the various rescue organizations is enhanced under the RMP Program.  An evaluation of 
the potential impact of released gas on the surrounding environment is also included in the RMP. USGS maps showing the effected areas within the endpoint distance are filed within the facility's RMP.  The estimated population within the 3.0 mile endpoint radius is 1,100 persons. 
   In the Alternative Release Scenario the Union Springs WWTP adopted conditions of uncontrolled release in which the failure of a check valve results in the release of the regulated gas for a period of  approximately 60 minutes.  At this time the gas leak is arrested and brought under control by emergency response personnel.  The endpoint radius for Chlorine was calculated to be 1.2 miles (Union Springs WWTP chose a scenario provided by the AWWA's Compliance Guidance and Model Risk Management Program for Water Treatment Plants).  Mitigation features which may impede the dispersal of the released gases, such as an enclosed building, were integrated into the Alternative Release Scenario calculations.  The pop 
ulation of Union Springs affected within the 1.2 radius is estimated at 170 persons. 
    Currently the regulated gases are connected to the Chlorine process in a fire proof, brick building located along US Hwy 82 East, approximately 2 miles east from the town of Union Springs.  A two ton hoist system removes the ton containers from delivery trucks and secures them inside this building for processing.  A Chlorine detector is in place, set to activate an alarm system at 1 parts per million concentration. This detector is tested everyday for responsiveness.  A new detector has been ordered following recommendations from the Plant's Hazard Review of the Chlorine process. In the event of a partial release of Chlorine gas it is anticipated that the bulk of the gas will be contained within the immediate vicinity of the Chlorine building considering the closed nature and construction of the Chlorine building. 
    There has been no accidental release of Chlorine gas beyond incidental e 
vents, such as minor leaks, in the last five years. 
    During the development of the Union Springs WWTP's RMP Program several recommendations were made which are currently being addressed.  Recommendations were introduced for windsocks, sirens, upgrading engineering process materials and instruments, and further upgrading Union Springs WWTP's standard operating procedures for all process activities which are material to the Chlorine process.  In addition, training will be improved and documented assuring that all Operators at the Union Springs WWTP are competently trained in the design and everyday handling of Chlorine gas.
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