GB Biosciences Corporation / Greens Bayou Plant - Executive Summary
Section 1. - Facility Information |
The GB Biosciences facility produces agricultural chemicals. The plant has four covered processes - Arsonates, IPN (Isophthalonitrile), CTL (Chlorothalonil), and chlorine distribution.
Arsonates products are post-emergence herbicides that kill such problem weeds as Johnson grass, cocklebur, and nutsedge, in cotton, turf and non-crop areas. Methyl Chloride is used in the process as a raw material. Methyl Chloride is stored in a 16,000 gallon vessel. It is used in the reaction section of the unit to make our product. The vent from this operation is sent to an incinerator for destruction prior to discharge to the atmosphere.
The chlorothalonil unit produces a fungicide, trade name Daconilb and Bravob which is a fungicide for bananas, potatoes, peanuts, turf and other crop areas. Chlorine is received in 180,000 pound rail cars, and is unloaded and distributed as a raw material in this process. Chlorine is reacted with the IPN (Isophthalonitrile
) to form chlorothalonil in a vapor phase reaction in the presence of catalyst.
IPN (Isophthalonitrile) produces a feed stock to our product chlorothalonil. Ammonia is used as a raw material in the IPN (Isophthalonitrile) process. Metaxylene and ammonia are reacted together with catalyst to make IPN (Isophthalonitrile). Ammonia enters the plant by rail car or tank truck. Ammonia is then stored in a 12,000 gallon storage tank.
The plant has a chlorine distribution process which provides chlorine gas to the chlorothalonil units. Chlorine comes into the plant in rail cars and is vaporized and then transferred to the chlorothalonil units via pipeline.
Section 2. - Toxics: Worst Case Scenarios
GB Biosciences has three (3) regulated chemicals above the threshold quantity- ammonia, chlorine and methyl chloride. The 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 specific endpoint. The worst case for the GB Biosciences site is the chlorine rail cars. The worst case scenario assume atmospheric stability class F (stable atmosphere), wind speed of 3.4 miles per hour, urban terrain, and ambient air temperatures of 770F. These events are very unlikely and are presented here to initiate dialog with the public and not as the sole or primary basis for local emergency planning consideration. A chlorine rail car is our largest quantity of a regulated substance.
The worst case for our facility is the rupture of a chlorine rail car. For purpose of this scenario, the rail car is assumed to release its entire contents (180,000 pounds) in 10 minutes in a 3.4 mile per hour wind. This results in a distance to toxic endpoint of 14 miles. There are additional existing safeguards which were not taken into account in the analysis:
Rail cars are designed and inspected for mechanical integrity per Department of Transportation (DOT) requireme
There are derails installed to prevent a loaded rail car from being bumped into a sited car,
Excess flow check valves on rail car which would limit size of release in case of failure of outlet piping,
Manually activated shutdown system which isolates the loading operation from the process,
Area chlorine detectors in the unloading area,
Ability to line up rail car to our emergency scrubber, and
Trained emergency response team.
The worst cases for both ammonia and methyl chloride result in smaller distances to the toxic endpoint or lesser off-site consequences.
Section 3. - Toxics: Alternative Release Scenarios
The three alternative cases identified were ruptures of the unloading hoses or piping systems for ammonia, chlorine and methyl chloride. The cases were all based on isolation of the process side from the leak and failure of the excess flow valves on the rail cars.
The alternate release scenario for ammonia is a complete rupture of the unloading arm. Assuming
a rupture of the arm, the amount released would be 498 lb/min. Under normal conditions(3 m/s wind speed and Class D stability), the distance to toxic endpoint is 0.50 miles.
Ammonia is unloaded through an unloading arm. The pressure of the ammonia in the rail car or pressure provided by compressing ammonia using our pad compressors is used to transfer the ammonia from the rail car to the storage tank or process. There are several prevention measures that are employed to prevent an accident of this magnitude. The loading arm is connected at the rail car with a breakaway coupling. This coupling is a double check valve that is designed to stop the flow from either direction to the environment. The break away coupling is the weak link in the piping system. If the rail car is moved while still connected, the breakaway coupling will separate while stopping the flow from either direction to the environment. The unloading area is continuously monitored via video camera in our operat
ing control area. The area is also equipped with ammonia detectors which alarm the operators in the control room. There is also a shutdown system on the unloading operation that isolates the rail car, storage tank and pad compressors.
The alternate release scenario for chlorine is a complete rupture of the unloading arm. Assuming a rupture of the arm, the amount released would be 558 lb/min. Under normal conditions (3 m/s wind speed and Class D stability), the distance to toxic endpoint is 0.80 miles.
Chlorine is also unloaded under pressure through a loading arm to the process. There are no storage vessels of chlorine in the system. Chlorine liquid is transferred from the rail car to the vaporizers where it is vaporized and transferred throughout our processes. The vaporized chlorine is also used to pressure the material from the rail car. There is an isolation system which closes valves around the unloading operation. This shutdown can be activated manually
remotely or activated based on chlorine detectors in the area.
Methyl Chloride -
The alternate release scenario for methyl chloride is a complete rupture of the unloading arm. Assuming a rupture of the arm, the amount released would be 345 lb/min. Under normal conditions (3 m/s wind speed and Class D stability), the distance to toxic endpoint is 0.40 miles.
Methyl chloride is unloaded under pressure through the loading arm to the Methyl Chloride storage tank. The pressure is provided by the methyl chloride in the rail car or by methyl chloride which is vaporized by a vaporizer. The vapors are used to transfer liquid material from the rail car. The system is designed to remotely manually activate a trip system which will block in the methyl chloride storage tank thereby preventing back flow of the storage tank through any ruptures in the unloading system.
Section 4. - Flammable: Worst Case
Section 5. - Flammable: Alternative Release
Section 6. - Accident History
Over the past five years, the facility has experienced four accidental releases that met the RMP reporting criteria. None of these four incidents involved any off-site injuries or other off-site impacts. In November 1995 and July 1998, we experienced incidents that involved the release of chlorine from our manufacturing units. The November 1995 incident was the largest (51 pounds) and resulted in injuries to three of our employees. The July 1998 chlorine release was smaller (29 pounds), and caused equipment damage.
The November 1997 and May 1999 incidents involved our taking the precautionary step of requesting that neighbors shelter-in-place until we could assess and control the upset situation. The November 1997 methyl chloride incident involved a maintenance activity, by a company adjacent to our plant, resulting in an impact to one of our storage tanks. Emergency response activities were coordinated by our facility. Maintenance improvements with training, documentation an
d equipment upgrades were completed by our neighboring company responsible for the maintenance activity. The May 1999 incident resulted in (20 pounds) chlorine being released outside of the unit boundaries. No injuries, illnesses or outside complaints were reported.
Section 7. - Prevention Program Level 3
GB Biosciences has three (3) regulated chemicals above the threshold quantity- ammonia, chlorine and methyl chloride. GB Biosciences has identified four covered processes - Arsonates process, IPN (Isophthalonitrile) process, chlorothalonil process, and chlorine distribution. These processes correspond to the way the plant is subdivided and the process hazard analysis were performed. Each process unit conducted a global process hazard analysis using the HAZOP methodology. Project and changes are handled with management of change. These changes have an additional appropriate process hazards analysis (Whatif/Checklist, Checklist, FMEA, Fault tree, etc.) performed. The PHA pres
ented in the RMP Plan are the comprehensive unit HAZOPs. On a five year interval, the unit HAZOP will be re-validated and incorporating the project and change hazard analysis findings.
The equipment for each area has been screened to determine if it can result in a catastrophic release to the environment. This equipment has been classified as PSM covered. This equipment will be inspected on a frequency determined internally based on past performance. Any problems found during the inspections will be repaired in a timely manner.
There are operating procedures and maintenance procedures for each unit. These procedures are reviewed and certified once a year. GB Biosciences has developed computer based training on each procedure which must be passed by those affected by that procedure once a year. Training records are kept of this activity.
All incidents are investigated to determine cause and to prevent recurrence.
Changes To Improve Safety
During 1997, the Ammonia Storage
Tank capacity was significantly reduced. The Storage capacity went from 60,000 gallons to 12,000 gallons.
Instituted administrative control limiting the chlorine volume in the Chlorine Vaporizers.
Release reduction teams in the IPN (Isophthalonitrile) and chlorothalonil areas.
Plans are to significantly reduce the chlorine volume in the Chlorine Vaporizer system by feeding chlorine liquid directly into system.
Section 8. - Prevention Program Level 2
Section 9. - Emergency Response
The Greens Bayou site has a 24 hour emergency response system in place. The site operates under a Incident Command System (ICS) for all emergencies. GB Biosciences has personnel on site trained to respond to fires, hazardous material releases, medical needs, and rescue situations 24 hours a day, seven days a week. Emergency team members are issued alpha numeric pagers so that they can be notified for assistance as needed. The shift superintendent is the Incident Commander. Quarterly training
is received by all emergency responders.
GB Biosciences is a member of the Channel Industries Mutual Aid organization (CIMA). CIMA is one of the largest mutual aid organizations offering emergency response assistance to member companies. GB Biosciences participates in an annual functional emergency response drills and training days with CIMA.
Additionally, the GB Biosciences has representation on the Local Emergency Planning Committee (LEPC) and the local Community Awareness and Emergency Response (CAER) group. GB Biosciences personnel also participated in functional drills with the LEPC and the CAER group. Both of these groups include the local fire department, sheriffs department, ambulance services, local hospital, neighboring industries and business owners.
GB Biosciences utilizes a series of air horns and electronic buzzers to communicate to the plant population, the type and location of an emergency. Critical plant personnel are also equipped with portable radios to ai
d in communications during an emergency. Radios are also in place for instant communications with neighboring industries and other CIMA members. Mobile radios have access to common state wide mutual aid frequencies to contact the fire department, ambulance service including the local air ambulance (Life Flight) The LEPC is currently installing a area telephone alerting system to contact area residence in the event of an incident that might have impact on the community.
GB Biosciences has its own internal fire water system (with backup supply). Most operating areas have fixed fire water systems installed and perimeter fixed fire monitors. Some areas have fixed gas detection systems in place to identify a possible leak and initiate an alarm in the appropriate control room for action. Video monitors have been installed in some areas allowing for continuous monitoring of primarily railcar unloading areas.
Local, state, and federal environmental agencies are contacted if the notifi
cation of an environmental release is necessary.