Phelps Dodge Morenci, Inc. - Executive Summary

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

The accidental release prevention and emergency response policies at our facility: 
This facility complies with all Mine Safety and Health Administration (MSHA) guidelines as well as other safety and environmental protection standards set forth by regulations and permit requirements.  It is Phelps Dodge Morenci Inc.'s. (PDMI's) policy to adhere to all applicable federal, state, and local laws.  If an emergency were to occur with the anhydrous sulfur dioxide (SO2) system, it is PDMI's policy to notify the Morenci Fire Association and other appropriate local agencies and request that they respond to the emergency as necessary. 
A description of your facility and the regulated substances handled: 
PDMI operates an open pit copper mine, ore processing and copper extraction facilities located in Greenlee County, Arizona.  PDMI uses SO2 to improve copper recovery efficiency in the ore processing facilities.  This is the only substance used at this facility that is reported  
under the risk management program rule. 
The worst-case release scenario: 
PDMI's worst-case scenario evaluated the failure of one 12,000-gallon SO2 storage tank when filled.  The tank is surrounded by a concrete berm and is enclosed in an 11,250-ft3 building.  Both the building and containment measures were assumed to be passive mitigation.  Based on EPA's Risk Management Program Guidance for Offsite Consequence Analysis the distance to endpoint in a "urban" (obstructed terrain) setting, typical of the terrain surrounding the site, is 0.3 miles.  Using the "rural" setting (unobstructed terrain), the distance to endpoint is 0.7 miles.  The worst-case release scenario from both the urban and rural settings would not affect any public receptors beyond PDMI's property boundary. 
The general accidental release prevention program and chemical-specific prevention steps: 
This facility complies with EPA's accident prevention rule and all applicable state and local codes and regulations. The SO2 
system is designed, installed, and maintained in accordance with MSHA guidelines. 
Five-year accident history: 
PDMI has not had any accidents involving SO2 that caused deaths, injuries, property or environmental damage, evacuations or sheltering in place. 
The emergency response program: 
In the event of an emergency involving the SO2 system, it is PDMI's policy to notify the Morenci Fire Association and other applicable local agencies and request that they respond to the emergency.  We have discussed this policy with the fire department; members of the fire department have inspected or sulfur dioxide system. 
Planned changes to improve safety: 
PDMI has plans to install an active mitigation system, during the next three months, which will route a release of SO2 through a system designed to capture and neutralize the SO2.  This active mitigation measure is not required to prevent a release of sulfur dioxide from affecting public receptors; however, it will make the system safer.
Click to return to beginning