On June 3, 2008, EPA Region 6 was notified by the National Response Center of a BNSF train accident and derailment located in Mammoth Springs, Fulton County, Arkansas. The incident site is immediately adjacent to Mammoth State Park, the Mammoth National Fish Hatchery, Mammoth Springs, and the Warm Fork River. The incident occurred at approximately 3:15 local time, after rail cars from a northbound train disconnected from the train's locomotive due to an unknown cause, and rolled back south. A second northbound BNSF train, running several miles behind the first train, was notified and stopped, but the runaway freight cars collided with the second train's lead locomotive. This resulted in a derailment of eighteen rail cars, including a car containing ammonium nitrate, a refrigerated car and attached diesel tank, and several empty flatcars and boxcars. Local fire, police and hazmat teams from West Plains, Missouri responded to the incident, as well as the Arkansas Department of Environmental Quality. Several empty rail cars fell into Mammoth Springs, but have been removed by BNSF work crews. The derailed car containing ammonium nitrate spilled approximately five cubic yards of the material onto soil; none was spilled into Mammoth Springs or the Warm Fork River. Approximately 350 gallons of diesel leaked onto ballast, but none discharged into the river. All oil and ammonium nitrate were contained at the site, and BNSF response crews have stabilized the scene. OSC Franklin and START were mobilized to the site to conduct assessment and on-scene monitoring activities.
