Only one fertilizer manufacturer in Arkansas currently reports storing both anhydrous ammonia and ammonium nitrate, the two chemical compounds thought to be responsible for the fertilizer plant explosion in West, Texas, on April 17.
El Dorado Chemical Co., a 400-acre chemical manufacturing plant in north El Dorado, uses anhydrous ammonia to produce more complex compounds, including ammonium nitrate, said Greg Withrow, the plant’s general manager. Anhydrous ammonia is pure ammonia, undiluted by water.
“It’s the raw material for this facility,” Withrow said.
The plant stores as much as 10,000 tons of anhydrous ammonia at any given time, Withrow said.
“We manage our plant safely,” Withrow said. “There are risks in everything we do every day, but the chemical industry itself has one of the lowest incident rates of any industry.”
In 2012, one of the company’s buildings in which it produced nitric acid exploded when a chemical reactor failed and ignited a sulfur fire. No injuries were reported.
Investigators have not determined the cause of the Texas explosion, which killed at least 15 people and injured another 200, according to The Associated Press. The Texas plant, West Fertilizer, contained more than 500,000 pounds of ammonium nitrate, a key component of the bomb that destroyed the Alfred P. Murrah Federal Building in Oklahoma City in 1995. Timothy McVeigh, who was executed for the bombing, reportedly used 4,000 pounds of ammonium nitrate.
Anhydrous ammonia and ammonium nitrate, both commonly used as fertilizers, are combustible because of their chemical makeup.
The Arkansas Department of Agriculture lists more than 180 facilities that store fertilizers throughout the state, but the majority are either county cooperatives or agricultural retailers or wholesalers, said Jamey Johnson, director of the fertilizer division at the state Plant Board.
El Dorado Chemical Co. is one of seven facilities the Environmental Quality Department identifies as “fertilizer plants,” and the only one of the seven reporting anhydrous ammonia on its federal air-permit application.
In Arkansas, the primary use of anhydrous ammonia is as a refrigerant, similar to Freon, in cold storage warehouses and large air-conditioning systems, said Kenny Harmon, hazardous materials program manager for the Arkansas Department of Emergency Management.
Anhydrous ammonia has a relatively small window of flammability - a gas mixture must be between 17 percent and 35 percent anhydrous ammonia to ignite; it poses a greater threat as an asphyxiant, meaning it displaces oxygen and can make breathing difficult or impossible, and has a pH base that can cause minor burns, Harmon said.
Any Arkansas facility that stores at least 100 pounds of anhydrous ammonia must submit an Emergency and Hazardous Chemical Inventory Form to the state Department of Emergency Management, as required by both the Arkansas Emergency Services Act of 1973 and the federal Emergency Planning and Community Right-to-Know Act. Facilities that store hazardous chemicals are also required to file hazardous chemical reports with local police and fire departments, hospitals, and other state and local emergency response agencies.
There are 140 facilities in Arkansas that are registered as currently storing 100 pounds or more of the anhydrous ammonia, Harmon said. The Arkansas Department of Labor inspects pressurized storage tanks containing the compound biannually.
RULES AND INCIDENTS
The federal Clean Air Act requires facilities that manufacture or store hazardous chemicals to address possible releases of toxic materials in the facilities’ risk-management plan. Anhydrous ammonia is covered under these requirements, but ammonium nitrate is not.
Sites that store 400 pounds or more of ammonium nitrate are required to report the material to both the state emergency management agencies and Department of Homeland Security under the Chemical Facility Anti-Terrorism Standards Act.
According to multiple news agencies, owners of the Texas plant failed to disclose the presence of the ammonium nitrate to the federal agency.
There were 28 sites in Arkansas that reported having 400 pounds or more of ammonium nitrate in 2012, the most recent year for which data is available, according to documents obtained from the state Department of Emergency Management. Most of the sites are farm-supply retailers.
According to National Response Center data, there were 227 documented discharge incidents in Arkansas involving anhydrous ammonia between 2002 and 2012. The majority of these, 217, occurred at fixed sites, resulting in the evacuation of more than 7,800 people from buildings. One fatality was reported in connection with anhydrous ammonia during that period.
Ammonium nitrate, which is more volatile, was tied to eight discharge incidents during the same period, with seven of those occurring during transport. In one of those incidents, the driver of a dump truck was killed in 2006 when he drove into a freight train in El Dorado. The impact derailed four rail cars.
REFRIGERANT LEAKS
Emergency responders have had to deal with leaks of anhydrous ammonia in refrigerated facilities such as poultry and meatpacking plants across the state. Both the Tyson Foods Inc. plant in Russellville and the Coleman plant in Jacksonville have had to evacuate their plants after suspected anhydrous ammonia leaks in the past decade, according to Arkansas Democrat-Gazette archives.
On Feb. 6, 2012, both the Tyson Foods Inc. Berry Street Plant and a Cargill turkey plant in Springdale experienced near-simultaneous leaks of anhydrous ammonia. No one was reported injured at the Cargill plant. Ten Tyson employees were treated for lung and eye irritation.
Kevin McDonald, assistant chief of the Springdale Fire Department, said eight facilities use anhydrous ammonia as a refrigerant in his department’s coverage area. His department has responded to anhydrous ammonia leaks within the city limits at least once a year for more than a decade.
Most leaks the department has responded to occur during maintenance or adjustments to pipes within the plants, which gives first responders a head start, McDonald said.
“[The plant managers] were right there when it happened, and they have a game plan in place,” McDonald said.
When fire crews respond to reports of anhydrous ammonia leaks, their first concern is for the safety of those inside the building, McDonald said. In dealing with chemicals, responders factor in not only the inherent dangers of the compounds themselves, but also wind speed and direction, time of day, and other variables. Responders tend to be more methodical in their approach to chemical leaks than with other situations, he said.
“It’s not like a house fire, where you’re moving as fast as you can, because time is of the essence,” McDonald said. “It’s just the opposite. It’s not that we’re moving slower, but we put more planning into our efforts.”
LEARNING MOMENT
The El Dorado Chemical Co. doesn’t plan to rebuild the nitric-acid facility that burned in the May 2012 explosion because it was centered around outdated technology, Withrow said.
The El Dorado plant, which was founded in 1940 and now employs about 200 workers, takes safety seriously and operates within guidelines put forth by the federal Occupational Safety and Health Administration, the federal Environmental Protection Agency and other regulatory agencies, Withrow said.
Although the Texas plant explosion has not led El Dorado Chemical Co. to review company protocols, any event is a possible learning experience for the company, he said.
“Once investigators release their findings, we’ll definitely look at it to help improve our safety,” Withrow said.
Industrial manufacturing is part of life in El Dorado, said Mayor Frank Hesh.
“Certainly, we do have concerns,” Hesh said. “The city is literally surrounded by industries that manufacture hazardous materials.”
In addition to the chemical company, El Dorado is home to the Lion Oil refinery, Great Lakes Chemical Corp. and Clean Harbors Environmental Services, among other plants.
“These operations have been going on for years and years,” Hesh said. “Occasionally, there are unfortunate accidents, but our industries do everything they can.”
Front Section, Pages 1 on 04/27/2013