Two days after the Boston Marathon bombing, a humongous explosion rocked the Texas town of West when a fire broke out at an agriculture retail facility storing ammonium nitrate. 14 people were killed, more than 200 injured, but despite leaving a crater 93 feet wide and 10 feet deep, the incident played second fiddle in the worldwide news-cycle to a terrorist attack and subsequent manhunt.
Authorities have struggled to piece together what happened to cause such a large explosion. Even though ammonium nitrate is often used in terrorist attacks like the Oklahoma City bombing in 1995 and the attempted Times Square bombing in 2010, the facility hadn’t been fully inspected in decades.
As a result, there is no verified estimate of how much ammonia was stored at the facility, and in which form. News coverage included 270 tons of ammonium nitrate as well as 27 tons of anhydrous ammonia, but both of these estimates come from the facility’s reporting—which also failed to consider the volatility of these chemicals as a hazard.
Ammonium nitrate is not the nitrogen source of choice in American agriculture, only accounting for two percent of all applied nitrogen in the field. Urea and anhydrous ammonia are more popular, and do not carry the regulatory burden of being a terrorist weapon of choice. Yet all of these forms of ammonia carry some degree of hazard and have been embraced by American agriculture for a multitude of uses, from fertilizer to refrigeration to even food processing.
Perhaps one of the scarier points of consideration is that there are 30 nitrogen fertilizer production plants and an estimated 6,000 retail facilities (like the one that blew up) across the United States. For the most part, however, these facilities don’t explode. In total, there have only been 18 recorded industrial explosions involving ammonium nitrate around the world.
What many advocates consider scarier, though, is that all of this volatile material is deposited in farm fields, where it feeds the explosive growth of industrial agriculture. In all, 12.3 million tons of nitrogen fertilizer was used in the U.S. in 2010. Corn farming is thought to be the most nitrogen-intensive crop and the amount used has skyrocketed. Corn farmers applied an average of 58 pounds of nitrogen per acre in 1964; by 1985, that average had jumped to 140 pounds per acre. And while the average amount of nitrogen used has remained stable since then, the amount of acreage for corn fields has grown to levels not seen since the Dust Bowl of the mid 1930s.
One of the main problems with nitrogen fertilizer is that too much is applied. The U.S. Department of Agriculture established best management practices for applying nitrogen fertilizer, but these practices are only used for 35 percent of U.S. field crops. Some of what is applied invariably escapes the farm fields—either while being applied or when decomposing in the field—and becomes a pollutant contributing to climate change.
When it rains, much of the excess nitrogen that the crops don’t absorb gets washed off the fields and into creeks, streams and rivers. In the water, the fertilizer promotes plant growth as well—plankton and simple algae—which then suck up most of the oxygen in the water and create deadzones where nothing else can thrive.
These deadzones have grown in the Gulf of Mexico and other places where water accumulates from rivers that drain agriculture land. The resulting impacts on the environment and regional economies—deadzones devastate everything from fisheries to tourism—have been well documented. But solutions remain on the wish lists of advocates as agriculture reform remains as elusive as chemical safety reform.
Perhaps the tragedy of West, Texas, can spur an empowered call for reform, which could include stronger limits on the use of ammonia, for example, or how it is stored. To be successful, reform would have to move through a powerful wall of lobbyists and entrenched interests. But the overuse of nitrogen in agriculture—which provides trouble from every point in the production process and beyond—presents an imperative that is growing too large to ignore.