SNF Holding Company - Riceboro, GA Facilities - Executive Summary |
|
EXECUTIVE SUMMARY This Risk Management Plan (RMP) has been prepared to meet the requirements of the Risk Management Program Rule. The RMP covers the following facilities which are under common control by SNF Holding Company (SNF): Chemtall Incorporated, and NCF Manufacturing, Inc. As part of complying with the Risk Management Program Rule, SNF has reviewed and enhanced previously existing accidental release procedures and emergency response policies. These policies include: Emergency Response Program Emergency Action Plan Spill Prevention Control and Countermeasure Plan Process Safety Management Plan Hurricane and Tropical Storm Plan First Responder Team Hazard Communication Plan Hazardous Waste Management Plan StormWater Pollution Prevention Plan Safe Work Pr actices Hazmat/Hazwoper Team There are four substances at the SNF facility that are regulated by the Chemical Accident Prevention Provisions defined at 40 CFR 68. These substances are used in various processes throughout the facility to produce water treatment polymers. These substances and the specific processes covered include: Toxic Substances: Methyl chloride: This material is used in the chloromethylation (CM) plant at Chemtall. The CM Plant uses methyl chloride as a reactant to produce quaternized monomers that are subsequently used in other facility processes to produce water treatment chemicals. The CM plant products are also sold to off-site customers. The maximum quantity of methyl chloride stored on-site is 210,000 pounds. Ammonium hydroxide: Ammonium hydroxide is received and stored at the facility as a 30 percent aqueous solution. Ammonium hydroxide is used in Chemtall's emulsion plant pro cesses for batch neutralization to produce emulsion polymers. The maximum amount of 30 percent ammonium hydroxide stored on-site is 50,000 pounds (15,000 pounds pure ammonia). Formaldehyde: Formaldehyde is used as a reactant in Chemtall's Mannich process. Formaldehyde is received and stored as a 50 percent solution in water. The maximum amount of 50 percent formaldehyde stored on-site is 96,000 pounds (48,000 pounds pure formaldehyde). Flammable Substances: Dimethylamine: Dimethylamine (DMA) is also used in the Mannich process as a reactant. Dimethylamine is received and used as a 60 percent solution in water. The maximum amount of 60 percent dimethylamine stored on-site is approximately 200,000 pounds (120,000 pounds pure dimethylamine). As required by the Risk Management Program Rule, worst-case and alternate (or realistic) release scenarios were evaluated and discussed in this RMP. As required, worst-case sce narios are presented in the RMP for one toxic substance and one flammable substance. Alternate scenarios were prepared for each of the toxic substances with worst-case endpoints located offsite (methyl chloride, formaldehyde, and ammonium hydroxide) and for one flammable substance to represent all flammable substances. The endpoint represents the distance at which a released substance must travel before it disperses sufficiently to no longer pose a hazard to the public. For the worst-case scenario, EPA has defined a worst-case release as the release of the largest quantity of a regulated substance from a vessel or process line failure that results in the greatest distance to a specified endpoint. For the worst-case analysis, the possible causes of the worst-case release or the probability that such a release might occur are not considered. The release is simply assumed to take place by suddenly releasing the entire contents of the vessel. The results of the worst-case scenario analysis were as follows: Toxics: The methyl chloride storage tank was assumed to fail and to instantaneously release the entire tank contents. No passive mitigation controls were considered in limiting the release impacts. The distance to the toxic endpoint was estimated to be less than 1.06 miles. Flammables: The DMA storage tank was assumed to fail and subsequently produce an instantaneous release of the entire tank contents that results in a vapor cloud explosion. No passive mitigation controls were considered in limiting the release impacts. The distance to the explosion endpoint was estimated to be less than 0.37 miles. Alternate release scenarios are more realistic scenarios that result in off-site endpoints. For methyl chloride, ammonium hydroxide, and formaldehyde, releases were assumed to occur as a result of the uncoupling or rupture of a transfer hose during unloading operations for each substance. For flammable ma terials, the alternate release scenario assumed that dimethylamine was released as a result of the uncoupling or rupture of a hose during unloading operations. The results of the alternate release scenario analysis were as follows: Ammonium hydroxide: In the alternate scenario, 6,600 pounds of ammonium hydroxide, 30 percent (2,000 pounds pure ammonia) were assumed to be released. The release was assumed to be mitigated because the transfer operation is monitored closely by personnel. The release was assumed to occur over a 5-minute period. The distance to the toxic endpoint for this scenario was 0.31 miles. Formaldehyde: In the alternate scenario, 8,500 pounds of formaldehyde, 50 percent (4,200 pounds pure formaldehyde) were assumed to be released. The release was assumed to be mitigated because the transfer operation is monitored closely by personnel. The release was assumed to occur over a 5-minute period. The distance to the toxic endpoint for this scenario was 0.19 miles. Methyl chloride: For the alternate scenario, 6,900 pounds of methyl chloride were assumed to be released. The release was assumed to be mitigated because of leak detector sniffers that detect leaks during the transfer operation and automatically shut- down the transfer operation and alert personnel of the occurrence of leaks. The release was assumed to occur over a 2-minute time period. The distance to the toxic endpoint for this scenario was less than 0.37 miles. Dimethylamine: For the alternate scenario, 14,000 pounds of dimethylamine, 60 percent (8,700 pounds pure dimethylamine) were assumed to be released and result in a vapor cloud fire. The release was assumed to be mitigated because the transfer operation is monitored closely by personnel and the system is equipped with automated shut-off valves. The release was assumed to occur over a 5-minute ti me period. The distance to the endpoint for this scenario was less than 0.06 miles. To address potential accidental releases, an accidental release prevention program along with chemical specific prevention steps has been developed. Ammonium Hydroxide: The ammonium hydroxide prevention program includes the following process controls and mitigation systems: Vents Relief valves Check valves Backup pump Scrubbers Manual shutoffs Automatic shutoffs Interlocks Alarms and procedures Dikes Formaldehyde: The formaldehyde prevention program includes the following process controls and mitigation systems: Vents Check valves Backup pump Scrubbers Manual shutoffs Autom atic shutoffs Interlocks Alarms and procedures Grounding equipment Dikes Dimethylamine: The dimethylamine prevention program includes the following process controls and mitigation systems: Vents Relief valves Check valves Backup pump Scrubbers Manual shutoffs Automatic shutoffs Interlocks Alarms and procedures Grounding equipment Rupture disks Excess flow device Purge system Dikes Water cannons Process area detectors Methyl chloride: The methyl chloride prevention program includes the following process controls and mitigation systems: Vents Emerge ncy air supply Relief valves Check valves Backup pump Scrubbers Manual shutoffs Automatic shutoffs Interlocks Alarms and procedures Emergency power Grounding equipment Rupture disks Excess flow device Quench system Sprinkler system Process area detectors Also included in the prevention program for the four substances listed above include the following programs, practices and procedures: Emergency Response Program Emergency Action Plan Spill Prevention Control and Countermeasure Plan Process Safety Management Plan Hurricane and Tropical Storm Plan First Responder Team Hazard Communication Plan Hazardous Waste Management Plan StormWater Pollution Prevention Plan Safe Work Practices Hazmat/Hazwoper Team Operator Training Operating procedures Additionally, the facility has programs to address the OSHA Process Safety Management (PSM) requirements. for several chemicals including methyl chloride, dimethylamine, and formaldehyde. The facility also has an emergency response program (ERP) that has been enhanced as part of implementing the Risk Management Program Rules. The ERP has historically been coordinated with the Liberty County Sheriff's and Fire Department, Liberty Memorial Medical Center, Liberty-Hinesville Emergency Management Agency, Life Star Rescue Helicopter, and Memorial Medical Center in Savannah, and will continue to be coordinated in this manner. As part of the community involvement efforts, the followi ng activities are coordinated with the departments and agencies listed above: Pre-emergency tours Emergency action drills Community evacuation procedures Material safety data sheets Responsibility roles in evacuation procedures Also, the facility has a supervised alarm system with United Alarms. United Alarms will notify the Fire Department and the Police Department in case of an emergency. As part of preparing the RMP, the facility's five year accident history was reviewed. One release was identified that involved off-site injuries related to the release of methyl chloride from Chemtall's chloromethylation plant reactor. Due to the unusually high pressure in the reactor, the pressure relief valve on the reactor vessel opened releasing part of the reactor contents to a containment vessel. However, due to the high pressure, the vessel manway gasket also blew out and released methyl c hloride into the atmosphere. The accident was believed to have been caused by excess iron in the methyl chloride which subsequently acted as a catalyst for polymerization of the product monomer. As a result of this release, Chemtall has modified the process by installing a magnetic filter between the methyl chloride storage tank and the reactors and by increasing the relief vent line size. SNF is committed to continuous improvement of safety. Planned changes and policies to promote this improvement include continuous review and update of the facility's ERP and various environmental, health, and safety polices, procedures, and practices. These include all the programs and plans listed above in the prevention programs as well as safety incentive programs to promote employee safety and community awareness programs. |