ST Microelectronics - Carrollton, Texas - Executive Summary

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The ST Microelectronics (STM) owns and operated a semiconductor plant located in Carrollton, TX  (northwest of Dallas County, Texas).  The approximate location of the plant is at latitude 32056'40" north and longitude 96054'56" west.  This executive summary is prepared in response to the requirements of 40 CFR '68.155 as part of the Risk Management Plan. 
 
THE ACCIDENTAL RELEASE PREVENTION AND EMERGENCY RESPONSE POLICIES 
 
It is STM's policy to adhere to all applicable Federal, state, and local rules and regulations to ensure chemical safety and prevent accidental releases of covered chemicals.  STM has developed a site emergency response plan, which includes ammonia spill response procedure.  The site Emergency Response Team members (ERT) are trained per 29 CFR1910.120. 
 
THE STATIONARY SOURCE AND REGULATED SUBSTANCES HANDLED 
 
Anhydrous ammonia, listed under Section 68.43 of the 40 CFR Part 68, is used as a neutralizer for the industrial wastewater pre-treatment process at this plant.  S 
ince the maximum storage quantity of ammonia exceeds 20,000 lb, the wastewater treatment process using ammonia is subject to the Risk Management Program (RMP) rule promulgated by the U.S. Environmental Protection Agency (EPA) in the Clean Air Act.  Since ammonia is regulated under OSHA's Process Safety Management (PSM) Standard, STM has completed a Program 3 Prevention Program to comply with the RMP rule. 
 
WORST CASE AND ALTERNATIVE RELEASE SCENARIOS 
 
Ammonia is a gas at ambient temperature but is stored as a liquid under pressure. Per 40 CFR '68.25, the worst case for a toxic gas is defined as a release of the greatest amount held in a single vessel over a 10-minute period.  STM has implemented administrative control to limit the storage amount to 9,000 gallons.  ALOHA was used for the dispersion modeling analysis of the worst case scenario.  Affected public receptors include schools, residences, recreation areas, and commercial, office, or industrial areas.  No environmental receptor 
s are affected. 
 
An alternative release scenario is an incident that is more likely to occur than the worst case scenario. The alternative release scenario is a release from the pressure relief valve of 2 inches in diameter on top of the horizontal cylindrical tank.  ALOHA was used for the dispersion modeling analysis of the alternative release scenario.  Affected public receptors include one nearby school and residences.  No environmental receptors are affected. 
 
THE GENERAL ACCIDENTAL RELEASE PREVENTION PROGRAM AND CHEMICAL-SPECIFIC PREVENTION STEPS 
 
STM is committed to preventing accidental releases of anhydrous ammonia and complies with the OSHA PSM rule.  The anhydrous ammonia system is designed, installed, and maintained in accordance with all applicable regulations.  STM employees having duties related to the handling of anhydrous ammonia are thoroughly trained on ammonia handling procedures.  Vendors who refill the ammonia storage tank are also properly trained in accordance wi 
th applicable rules, codes, and industry standards. 
 
FIVE YEAR ACCIDENT HISTORY 
 
There have been no accidental releases of anhydrous ammonia from the covered process at the STM Carrollton facility in the past five years that have resulted in death, injury, or property damage on site, or known offsite impacts (deaths, injuries, evacuations, sheltering-in-place, property damage, or environmental damage). 
 
EMERGENCY RESPONSE PROGRAM 
 
If an accident involving anhydrous ammonia were to occur, an emergency response program developed by the facility would be implemented.  The plan defines the proper procedures for the employees (specifically evacuation) and who to contact in the event of an emergency. 
 
PLANNED CHANGES TO IMPROVE SAFETY 
 
In order to eliminate any possibility of ammonia accidental releases from this process, STM is in the process of replacing ammonia with chemicals that are not listed under 40 CFR Part 68 for safer future operations.  In addition, STM is an ISO 14001 certified  
facility, which implements a successful environmental management program that includes most of the elements required under the RMP rule throughout the entire plant.
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