At approximately 2230 on 4/26/2012, a 750ft railroad tunnel operated by CSX began burning near Robinson Creek in Pike County, Kentucky. The rail line is active with a traffic frequency of 15-20 trains per month from two coal mines. The tunnel is reportedly constructed with a timber frame support structure. By 4/27 the entire length of the tunnel had ignited and smoke from the fire caused the cancellation of classes at both nearby elementary and high school on 4/28. On either side of the tunnel are nearby residential properties and within 1/4-mile of the tunnel on the east side of Hwy 23 is an elementary school, a high school, a public housing neighborhood, a church, and two retirement facilities. EPA remained in communication with KYDEP on 4/27, but by 4/28 both Pike County EMA and KYDEP requested EPA assistance with air monitoring in the nearby communities.
By approximately 1400-1600hrs on 4/28, heavy equipment was on-site at both sides of the tunnel moving soil to “plug” the entrance and exit. Flames and smoke from the fire had subsided but the smoke plume was still visible for several miles. Soil was supplied to the south entrance by dump trucks traveling on “high rail” systems while was supplied to the north side from a borrow pit that was dug near the opening.
EPA OSC Huyser arrived on-scene by 1730 on 4/28 and began coordinating with KYDEP, Pike County EMA, and CSX's Environmental services. EPA and START contractor, Tetra Tech, established remote air monitoring stations at the tunnel high elevation entrance and at the nearby elementary school. Based on recommended air monitoring parameters from ERT, it was decided that exposure levels for PAHs and other chemical constituents that may have been emitted were likely to be significantly low due to dispersion and limited exposure time - the greatest response information would be gathered from particulate monitoring. Particulate concentrations were compared to site specific parameters which were primarily develop from a July 2008 document: “Wildfire Smoke: A Guide for Public Health Officials” (this document has been used frequently in EPA R4 emergency response operations for particulate monitoring around fire events). Particulate levels through the night of 4/29 were consistently at or slightly above a “moderate” AQI rating, even with regular interference from high humidity, heavy rainfall, and dense fog (the fog is common for the area). Information on nighttime readings were communicated to Pike County EMA. Schools reopened on Tuesday morning.
CSX completed plugging both ends of the tunnel by early morning on 4/29 but a thin stream of smoke continued to escape at the south opening. Crews resumed working through 4/29 and successfully sealed the tunnel with only slight pockets of smoke escaping by early afternoon. Tunnel emergency specialists arrived on-scene by 4/29 to develop response and engineering plans for further actions. Removing the plug to assess whether smothering was successful and addressing remaining hotspots may not occur until Monday (5/5/14). Pump trucks and tanks were mobilized by CSX on 4/29 to capture discolored water that was discharging from the low elevation side of the tunnel.
EPA’s 12-hour continuous air monitoring during the night of 4/28 measured particulate levels that were slightly elevated (avg 50 ug/m3) with a peak during daybreak hours, but below general health risk concerns for emergency response. A 6-hour continuous monitoring run during the day of 4/29 showed that particulate levels dropped significantly (<10 ug/m3) to what can be considered background or “normal” concentrations. Another 13-hour monitoring run during the night of 4/29 confirmed that the background or “normal” concentrations were steady throughout the night and into the morning.
