Water Treatment Plant - Executive Summary

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EXECUTIVE SUMMARY 
 
We have adopted this Program in order to implement 40 C.F.R. 68, the federal requirements regulating Risk Management of Highly Hazardous Chemicals. 
 
This Program will help prevent the occurrence of, or minimize the consequences of, catastrophic releases by stating our policies and guidelines for the management of process hazards in start-up, operation, inspection, maintenance and the other matters addressed in the federal standard. 
 
Our Program calls for maximum employee participation and includes all elements of the employee participation provisions of the federal standard.  We shall, as a minimum: (1) consult with employees and their representatives on the conduct and development of the process hazard review and other elements of the risk management plan, and (2) provide to our employees and their representatives access to the process hazard review and all other information required to be developed under that standard. 
 
Accidental Release Prevention and Emergency R 
esponse Policies 
 
The City of Greenville believes that preventative maintenance is the key to minimizing the potential for accidental releases.  Standard Operating Guidelines (SOGs) have been reviewed and revised to enable the employees to perform their work in a safe and efficient manner. 
 
The City of Greenville has taken steps to train the operators, supervisors, maintenance crews, and fire department to be first responders to a release.  The training included three days of classroom and hands on training on the proper use of emergency response equipment and guidelines.  The course followed the guidelines stated in OSHA 1910.120. 
 
Stationary Source and Regulated Substances 
 
The Water Treatment Plant (WTP) utilizes chlorine and ammonia (anhydrous) for disinfection of the treated water.  However, the maximum inventory of anhydrous ammonia maintained at the WTP is approximately 900 gallons or approximately 5,000 pounds.  The maximum inventory and threshold quantity for anhydrous ammonia 
is 10,000 pounds.  Anhydrous ammonia is therefore not being considered as part of the EPA requirement in the Risk Management Program. The maximum inventory and threshold quantities for chlorine and anhydrous ammonia are shown below. 
 
Chemical                                 Maximum Inventory (lb)             Threshold Quantity (lb) 
Chlorine                                           12,000                                           2,500 
Ammonia (anhydrous)                       5,000                                        10,000 
 
Offsite Consequence Analysis 
 
The offsite consequence analysis includes a worst-case release scenario and an alternative release scenario as defined in 40 C.F.R. 68.  A dense-gas dispersion model (SLAB) was used to determine endpoint distances for both scenarios.  The model's input parameters are summarized in the table below. 
 
SLAB Input Parameters 
                                                        Worst-Case Scenario               Alternative Scenario 
 
Windspeed (m/s)                                          1.5                                                 3 
Atmospheric Stability Class                           F                                                   D 
Temperature (0 F)                                       104                                                104 
Humidity (%)                                                50                                                  50 
Height of Release (m)                                   0                                                    1 
Surface Roughness                                     1                                                     1 
                                                             Chlorine 
End Points (mg/l)                                   0.0087 
 
The results of the air dispersion model are summarized in the table below along with the estimated population within the impact area. The population data was estimated using the Block Uniform density Gro 
up Method in Landview III.  The public and environmental receptors are listed in Section 2 and Section 7 of this plan. 
 
SLAB Output Results 
                                                                Worst-Case Scenario                Alternative Scenario 
                                                                      Chlorine                                         Chlorine 
Impact Radius (miles)                                         4                                                   0.5 
Estimated Population with Impact Area         1,800                                                494 
 
 
General Accidental Release Prevention Program 
 
The City of Greenville has implemented a General Accidental Release Prevention Program to minimize releases.  This Program includes:  safety information on the covered chemicals, hazard reviews, operating and maintenance guidelines, training, compliance audits, incident investigations, and emergency response guidelines.
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