Twin Valley Ag Service - Executive Summary

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             Risk Management Plan (RMP) - Ammonia 
                      Executive Summary 
                    Twin Valley Ag Service 
                       St. Charles, MN 
 1. Accidental Release Prevention and Emergency Response Policies 
We at Twin Valley Ag Service in St. Charles, MN are strongly committed to employee, public, and 
environmental safety.  This commitment is an inherent part of our comprehensive accidental release 
prevention program that covers areas such as design, installation, operating procedures, maintenance, 
and employee training associated with the processes at our facility.  It is our policy to implement 
appropriate controls to prevent possible releases of regulated substances.  If such a release does 
occur, our trained emergency response personnel are at hand to control and mitigate the effects of 
the release.  We also coordinate our response efforts with the St. Charles, Mn Fire Department, 
which provides additional emergency response expertise. 
 2. Stationary Source and Regulated Substances Handled 
Our facility's primary activities include support services for crop production.  We have anhydrous 
ammonia stored in a 18,000-gallon tank  at our facility in St. Charles, MN  (Figure 1).  The 
maximum amount stored is 16,122.8 gallons ( 84,000 pounds) at the maximum fill capacity of 86 
 3. Worst Case Release and Alternative Release Scenarios 
We utilized RMP PRO for the worst case and alternate case scenarios of the required offsite 
consequence analysis for our facility.  The following details these scenarios. 
The worst case release scenario involves a catastrophic release of the entire contents of the 18,000 
gal. anhydrous ammonia storage tank ( 84,000 pounds) in gaseous form over a 10-minute period.  
At Class F atmospheric stability, 1.5 m/s wind speed, and a urban topography, the maximum 
distance to a toxic endpoint of 0.14 mg/L is 4.2 miles (Figure 2).  The estimated 
population within 
a 4.2-mile radius of this facility is 5000. 
The alternative release scenario involves a release from an anhydrous ammonia product line.  The 
scenario involves the release of 11,642.4 pounds of ammonia in a gaseous form over a period of 30 
minutes.  Under neutral weather conditions, the maximum distance to the toxic endpoint of 0.14 
mg/L of ammonia is 0.31 mile (Figure 3).  The estimated population within a 0.31-mile radius of the 
facility is 1000. 
 4. General Accidental Release Prevention Program 
Our facility has taken all the necessary steps to comply with the EPA's accidental release prevention 
requirements as set forth in 40 CFR part 68.  The following sections briefly describe the elements 
of the release prevention program that is in place at our stationary source. 
Process Safety Information 
Twin Valley Ag Service maintains a detailed record of safety information that describes the chemical 
hazards, operating parameters, and equipment designs associated wit 
h all processes (Appendix D). 
Process Hazard Analysis 
Our facility conducts comprehensive studies to ensure that hazards associated with our processes are 
identified and controlled effectively.  Any findings from the hazard analysis are addressed in a 
timely manner. 
Operating Procedures 
Twin Valley Ag Service maintains written operating procedures to ensure that activities within our 
covered processes are conducted safely.  These procedures address various modes of operation; the 
information is regularly reviewed and is readily accessible to operators involved in the processes 
(Appendix B). 
Twin Valley Ag Service has a comprehensive training program in place to ensure that employees 
who are operating processes are competent in the operating procedures associated with these 
Mechanical Integrity 
Twin Valley Ag Service conducts documented maintenance checks on process equipment to ensure 
proper operation.  Maintenance checks are conducted by qualified personnel wit 
h previous training 
in maintenance practices.  Examples of process equipment that would receive maintenance checks 
include:  pressure vessels, storage tanks, piping systems, relief and vent systems, emergency 
shutdown systems, controls, and pumps.  Any equipment deficiencies identified by the maintenance 
checks are corrected in a safe and timely manner (Appendix C). 
Management of Change 
Written procedures are in place at twin Valley Ag Service to manage changes in process chemicals, 
technology, equipment, and procedures.  Process operators, maintenance personnel or other 
employees whose job tasks are affected by a modification in process conditions are promptly notified 
of the modification and offered training to deal with it. 
Pre-startup Reviews 
Twin Valley Ag Service routinely conducts pre-startup safety reviews related to new processes and 
modifications in established processes.  These reviews are conducted to confirm that construction, 
equipment, and operating and maintenance pro 
cedures are suitable for safe startup prior to placing 
equipment into operation. 
Compliance Audits 
Twin Valley Ag Service conducts compliance audits on a regular basis to determine whether the 
plan's provisions, set out under the 40 CFR part 68, are being implemented.  Any non-compliance 
issue discovered during the audit is promptly corrected. 
Employee Participation 
Twin Valley Ag Service truly believes that process safety management and accident prevention is 
a team effort.  Company employees are strongly encouraged to express their views concerning 
accident prevention issues and to recommend improvements.  In addition, our employees have access 
to all information created as part of the facility's implementation of the RMP, particularly 
information resulting from process hazard analyses. 
 5. Five-year Accident History 
Twin Valley Ag Service has had an excellent record of preventing accidental releases over the last 
5 years.  Due to our stringent release prevention policies, no a 
ccidental release has occurred during 
this period. 
 6. Emergency Response Plan 
Twin Valley Ag Service maintains a written emergency response plan to deal with accidental 
releases of hazardous materials.  The plan addresses all aspects of emergency response including first 
aid and medical treatment, evacuations, and notification of local emergency response agencies and 
the public (Appendix A).
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