American Crystal Sugar Co. - Moorhead Facility - Executive Summary
This document was developed for American Crystal Sugar Co. - Moorhead Facility (ACSC) in an effort to fulfill criteria of the Risk Management Program (RMP), as required by Section 112(r) of the Clean Air Act (CAA), and regulated by 40 CFR, Part 68. ACSC is a beet sugar manufacturing plant. The quantities of Sulfur Dioxide (SO2) and methane at the facility, are greater than the Threshold Quantities (TQ) of 5,000 pounds and 10,000 pounds for the respective chemicals. This is EPAs criteria for requiring the development and submittal of the information found in this RMP. A hazard assessment was conducted for the manufacturing process and consideration was also given to the other hazardous chemicals at the plant as well. |
SO2 is considered toxic, and methane is considered flammable by EPA standards. The same properties that make SO2 valuable for beet sugar processing, and methane as a fuel supply, also make it necessary to observe certain safety precautions in handling these chemicals
to prevent unnecessary human exposure, and to reduce the potential impact or threat to nearby members of the community and/or environment. Safety depends upon the manner in which we handle chemicals; combined with safety devices inherent in the design of this facility; and the training of our personnel.
THE ACCIDENTAL RELEASE PREVENTION AND EMERGENCY RESPONSE POLICIES
It is this facilitys intent to uphold industry standards in the design, construction and operation of the facility. It is our policy to adhere to all applicable federal, state, and local laws. If an emergency was to occur, we have trained personnel and equipment ready for response in the event of a spill of hazardous materials. It is also our policy to notify the Moorhead Fire Department (via the 911 system), and request that they respond to the emergency if the emergency is beyond our capabilities.
THE STATIONARY SOURCE AND REGULATED SUBSTANCES HANDLED
SO2 is used at the plant for processing the sugar beets int
o some of the various products. SO2 is received and stored in a 12,000 gallon pressurized tank. Inventory of SO2 held at the facility is a maximum of 108,952 pounds held in the tank along with residual in process piping. Liquid SO2 passes out of the tank, through process piping, then branches into one of two process endpoints. Prior to each end use, the SO2 passes through a vaporizer, which transitions it to a gaseous state. It then flows into the process endpoint. Approximately 75% of the SO2 is used in the diffuser water supply and the other 25% is used in the sulfitation of thin juice.
Methane is generated by the anaerobic digestion of facility waste water. As waste water is pumped through the digestion vessel, bacterial consumption of organic material in the water releases a flammable gaseous mixture. This mixture is composed of approximately 70% methane and the balance being carbon dioxide with traces of hydrogen and nitrogen gas. The volume of methane in the head spa
ce of the digester is calculated to be 17,717 lb. The methane is used as a fuel source for the pulp dryer furnaces and excess methane is burned off at a flaring station.
Physical access to the plant is restricted by 6 chain link fencing and manned security at all entry points.
WORST-CASE RELEASE SCENARIO AND THE ALTERNATIVE RELEASE SCENARIOS
RMP standards require that a Worst Case Scenario (WCS) representing all toxics be developed for covered processes, as well a WCS representing flammables. Following, are the WCSs for SO2 and methane, representatives of their respective hazards. Similarly, RMP rules require an Alternative Release Scenario (ARS) for these same chemicals.
WCS for SO2 -- 108,952 lb. is the maximum quantity of SO2 in a single storage vessel that can be released in a WCS. For WCS, according to EPAs Guidance Document EPA 550-B-98-010 criteria, the distance to toxic endpoint for this WCS is 11 miles. The facility is located in a populated, urban area with an est
imated population of 130,000 persons living within the 11 mile radius. No environmental receptors (as defined by 40 CFR Part 68) are located within this radius.
WCS Methane -- 17,717 lb. of methane is released and involved in a vapor cloud explosion. The distance to 1 psi overpressure is 0.22 miles using equations from Appendix C of Guidance Document EPA 550-B-96-014. There are an estimated 12 persons living within the 0.22 mile radius (per Landview III software*). No environmental receptors (as defined by 40 CFR Part 68) are located within this radius.
ARS for SO2 -- the release chosen is a < diameter hole releases SO2 for 5 minutes from the process line at the SO2 storage tank. The distance to toxic endpoint for this ARS is 0.2 miles, which reaches a public receptor (residential housing to the west of the plant) and an estimated population of within this distance (per Landview III software*).
ARS for Methane -- the entire contents of the tank is involved in a short duration
release (<4 minutes) and determined the distance to the Lower Flammable Limit (LFL) using Exhibit 4-26 of the RMP Guidance EPA 550-B-98-010. Assume urban conditions, D stability, and wind speed of 3.0 meters/sec. This yields a distance to endpoint of 0.2 miles. We chose this scenario to meet the RMP criteria of choosing an ARS which reaches a public receptor, if at all possible and the nearest receptors are at 0.2 miles.
* This Landview III software was issued Dec. 1997 and utilized 1990 census data.
2.1.4. THE GENERAL ACCIDENTAL RELEASE PREVENTION PROGRAM AND THE SPECIFIC PREVENTION STEPS
This facility complies with EPAs Accidental Release Prevention Rule and with all applicable state codes and regulations. ACSC takes a systematic, proactive approach to evaluating chemical processes. Using this approach, the design, technology, operation and maintenance activities, emergency preparedness plans, training, process changes, and other elements that affect the covered processes ar
e all considered. By conducting thorough evaluations, accidental releases are prevented and the consequences of releases are minimized.
By fulfilling the required elements of the RMP standards, ACSC intends to prevent releases of hazardous substances and minimize the impacts of accidental releases, especially into locations that could expose employees, the community or the environment to serious hazards. Our management systems address each of the key features of a successful release prevention program including:
( Maintaining Process Safety Information (PSI): ACSC maintains up-to date technical information about safe operating limits of the processes and the associated hazards of the chemicals involved.
( Conducting Process Hazard Analyses (PHA): ACSC performs technical analysis of the plants processes in order to anticipate what might go wrong and recommend approaches to minimize the possibilities and affects of such occurrences.
( Standard Operating Procedures (SOP): We have wri
tten technical and administrative procedures used to operate the plant safely.
( Training: ACSC provides employees with information necessary to ensure safe operation.
( Mechanical Integrity: We ensure proper maintenance of the process equipment on an ongoing basis.
( Management of Change (MOC): ACSC analyzes changes in process equipment, procedures and personnel to understand the impact of those changes in the safe operation of our plant.
( Pre-Startup Safety Review: We ensure all necessary elements for operating a safe process are in place prior to introducing the hazardous chemical into a new or modified system.
( Compliance Audits: We conduct periodic evaluation and updating of the process operation to ensure all RMP elements are being applied properly.
( Incident Investigation: ACSC has procedures for investigating the causes of near-miss or accidental releases and developing measures to prevent future similar occurrences.
( Employee Participation: We maintain a philosophy
and approach to incorporating the knowledge and experience of our employees from all facets of operation regarding the covered processes.
( Hot Work Permit: We have a documented program for controlling the hazards associated with ignition source activities, thereby minimizing potential catastrophic release.
( Contractors: ACSC upholds policies and procedures for ensuring safe work practices of contractors on the facility and a systematic approach of communicating hazards inherent to the covered processes which the contractor may be working on or near.
Our company and our employees are committed to the standards that the RMP regulation sets. We do business, and have specific accountabilities and controls to ensure that we are meeting high standards for accident prevention. ACSC has also developed a risk management system which identifies specific job positions and responsibilities to ensure proper management and implementation of this RMP.
FIVE-YEAR ACCIDENT HISTORY
been no accidental releases of SO2, methane, or other toxic/extremely hazardous chemicals in the past 5 years, which have resulted in off-site consequences such as personal injury, death, or response/ restoration activities.
THE EMERGENCY RESPONSE PROGRAM
We have discussed the content and intent of this program with the Moorhead Fire Department. We rely on our trained, in-house staff and on-site equipment for initial response (if safe to do so) and acquire backup support from the local fire department as needed.
PLANNED CHANGES TO IMPROVE SAFETY.
ACSC plans to install additional sensors, alarms and monitoring devices to our processes to improve our ability to detect and respond to accidental releases from process equipment.