A 2006 permit application to the Texas Commission on Environmental Quality noted the facility had the capacity to process up to 2,400 tons of ammonium nitrate. In 2012, West Fertilizer informed the Texas Department of State Health Services that 270 tons of ammonium nitrate and 55 tons of anhydrous were on hand at the facility.
Those figures never went reported - state officials were not required to do so - to the federal Department of Homeland Security, which has kept a database of fertilizer storage spots following the 1995 Oklahoma City bombing. In that attack, which killed 168, Timothy McVeigh and Terry Nichols constructed a bomb using roughly 5,000 pounds of ammonium nitrate fertilizer.
Under Homeland Security rules, fertilizer facilities must report their quantities when they have at least 400 pounds of ammonium nitrate. The 270 tons West Fertilizer reported to the Department of State Health Services is 1,350 times that amount.
One of the firefighters who died in the explosion was a company foreman, and a spokeswoman for the State Fire Marshal's Office, the lead state agency in the investigation, told the American-Statesman Monday that the West Fire Department had a copy of an annually filed report, known as a Tier II report, that lists hazardous materials at an industrial site - including the ammonium nitrate.
But whether individual firefighters knew about the ammonium nitrate remains an open question. If they had, they might have stood down instead of attacking the fire - as firefighters did during a fire at a fertilizer site on the outskirts of Bryan in Brazos County in 2009. Water can exacerbate conditions around ammonium nitrate.
In that incident, sparks from a welder's torch probably led to the fire, said Chuck Frazier, emergency management coordinator for Brazos County.
Having consulted a report detailing hazardous supplies and their quantities, the firefighters chose to evacuate much of Bryan and allow the fire to burn itself out, Frazier said. "We were fortunate not to have an explosion."