by Abrahm Lustgarten ProPublica, Sept. 20, 2012, 12:12 p.m.by Abrahm Lustgarten and Krista Kjellman Schmidt, ProPublica, Sept. 20
On a cold, overcast afternoon in January 2003, two tanker trucks backed up to an injection well site in a pasture outside Rosharon, Texas. There, under a steel shed, they began to unload thousands of gallons of wastewater for burial deep beneath the earth.
The waste – the byproduct of oil and gas drilling – was described in regulatory documents as a benign mixture of salt and water. But as the liquid rushed from the trucks, it released a billowing vapor of far more volatile materials, including benzene and other flammable hydrocarbons.
The truck engines, left to idle by their drivers, sucked the fumes from the air, revving into a high-pitched whine. Before anyone could react, one of the trucks backfired, releasing a spark that ignited the invisible cloud.