El Dorado Water Utilities Mt. Holly Pump Station - Executive Summary

| Accident History | Chemicals | Emergency Response | Registration | Source | Executive Summary |

Executive Summary 
 
Policy Statement 
 
It is El Dorado's policy to operate the Mt. Holly Pump Station safely, reducing to the greatest extent possible any hazards associated with the chlorine system and reducing any subsequent risk to the surrounding community, personnel, and environment.  Safe operation depends on proper storage of chlorine, proper handling of the chlorination system, and inherent safety features in the design of the chlorination system.  Safety in storage and handling is achieved through the use of safe handling procedures and training of personnel. 
 
The policy includes working with the surrounding community and local emergency response agencies to promote a spirit of cooperation and teamwork, to orchestrate an effective contingency plan in the unikely event of a process incident occurring at the Mt. Holly Pump Station.  The emergency response plan includes procedures for notifying the El Dorado Fire Department. 
 
Stationary Sources and Regulated Substance Handled 
 
Pri 
mary Activities 
 
Water Treatment. 
 
Use of Regulated Substances 
 
Chlorine is used primarily as a disinfectant.  Other possible uses of chlorine are for odor control and to assist in the settling of biosolids in the clarification process. 
 
Quantities Handled or Stored 
 
Chlorine 
Total Amount Stored: 3 one-ton containers, equivalent to 6,000 pounds. 
 
Worst -Case Release Scenario 
 
Chlorine 
* WRS:  Failure of one liquid chlorine container resulting in a release of 2,000 pounds of chlorine gas in 10 minutes.  Passive mitigation is considered because the containers are stored in an enclosed space.  The release rate of 110 lbs/min is modeled using RMP Comp.   
 
* Distance to Endpoint:  Under the worst-case weather conditions prescribed by the RMP Rule, the distance to a toxic endpoint of .0087 mg/L (or 3ppm) is .9 miles, beyond which there will be enough dispersion that a hazard to the public will no longer exist. 
 
* Population Exposed:  It is estimated, based on the averaged USCB population den 
sities for the City of El Dorado that 1,368 persons would be affected with the WRS toxic endpoint circle. 
 
* Environmental Receptors:  There are no environmental receptors within the WRS toxic endpoint circle. 
 
Alternative Release Scenario 
 
Chlorine  
 
ARS:  Release of chlorine from a 1/2 inch-diameter pipe connecting the chlorine container to the feed manifold.  For a release duration of 20 minutes, the calculated release rate is 53.8 lbs/min.  The release rate calculation is based on a tank pressure of 7.93 atm and a tank temperature of 77 degrees F with a passive mitigation of 45 percent because of the tanks are in an enclose space.   
 
Distance to Endpoint: Under realistic weather conditions of 3.0 m/s wind speed and a wind stability class of "D", chlorine would travel .1 miles. 
 
Population Exposed: It is estimated, based on the USCB population density for the City of El Dorado, that 10 persons would be affected within the ARS toxic endpoint circle. 
 
Environmental Receptors: There ar 
e no environmental receptors within the ARS toxic endpoint circle. 
 
Accidental Release Prevention Program and Chemical-specific Prevention Steps 
 
The El Dorado Water Utilities Mt. Holly Pump Station is in compliance with RMP Rule, 40 CFR 68.  The facility has conducted a comprehensive review of all system and of administrative, technical, and operating and maintenance procedures, in addition to the other required program elements of the RMP Rule.  A hazard review was conducted at this facility using a "What If" analysis. 
 
Five-year Accident History  
 
The El Dorado Water Utilities Mt. Holly Pump Station has never had a release of chlorine resulting in offsite injury or dispersion, or in onsite injury. 
 
Emergency Response Program 
 
The El Dorado Water Utilities Mt. Holly Pump Station has an Emergency Procedures Plan, which coordinates response efforts with the El Dorado Fire Department's HAZMAT team, the police department, and the hospital.  Response activities also have been discussed wi 
th the Arkansas Office of Emergency Services. 
 
Planned Changes to Improve Safety 
 
It was observed during the hazard review that the El Dorado Water Utilities Mt. Holly Pump Station has the necessary equipment and the operating and training procedures required for the safe operation of the chlorination system.  The following recommendations for improving the safety of the chlorination process were made: 
 
1. Change the set point for the chlorine detection and alarm system for 3 ppm. 
2. Provide a copy of the updated emergency response procedures for chlorine to the El Dorado Fire Department.
Click to return to beginning