An explosion involving two fatalities occurred at Carbide Industries in Louisville, Kentucky on March 21, 2011 at approximately 1740 hours EDT. The building is approximately the height of a ten-story building, but only contains five-stories with catwalks for flooring. It was determined that water could not be applied to the fire because calcium carbide contained within the building is water reactive creating acetylene gas, therefore the decision was made to let the building burn itself out. The building is composed of a non-insulated steel structure with steel, wood, and concrete flooring. The third floor contains four, 5,500 gallon mineral oil tanks that are believed to have burned overnight in the fire. A furnace exists at the bottom floor of the building and contains anthracite coal tar pitch. Also, a hydraulic system that uses hydraulic glycol exists within the building.
Air monitoring has been conducted by the local fire department (Lake Dreamland Fire Department), Carbide Industries, Louisville Metro Health Department (LMPHD), and Louisville Air Pollution Control District (LAPCD). Lake Dreamland conducted air monitoring on March 21, 2011 within the immediate area of the incident and some around the perimeter of the site using Area Raes, multi-gas instrument, and Q Raes for lower explosive limit (LEL), oxygen, ammonia, chlorine, volatile organic compounds (VOCs), and individual monitors for carbon monoxide. Carbon monoxide readings were as high as 100 parts per million (ppm) within the immediate hot zone on the plant property. Carbon monoxide was not monitored outside the hotzone. Metro Health began conducting air monitoring immediately after the explosion occurred and continues to conduct air monitoring using Area Raes for LEL, oxygen, ammonia, chlorine, and VOCs in a general two-mile perimeter of the incident site. No significant readings were documented during these monitoring events. LAPCD maintains fixed air monitoring stations in the area of the incident based upon the heavy industrial activity in the area. Air monitoring results from these locations indicated a slight elevation in particulate matter 2.5, but no significant readings were observed. Carbide Industries indicated that one of their personal carbon monoxide monitors produced a peak range reading of approximately 35 - 40 ppm. No other monitoring has been conducted by Carbide Industries. A residential evacuation never took place as a result of the incident.
As of 1200 hrs. on 03/24, all fires inside the building were declared out by the Lake Dreamland FD. Conditions inside the furnace building have improved and areas cleared for access by a structural engineer. The OSC completed the removal site evaluation process on 03/26.
The OSC's findings are that no additional federal response is warranted, and outlined as follows:
1. The release of calcium carbide is not governed under Section 311(c)(1) of the Clean Water Act.
2. The quantity of calcium carbide which has been released is unknown. However, areas outside of the furnace building where calcium carbide has been observed do not reveal significant accumulations to be present. (see Images section of the website: www.epaosc.orgcarbideindustriesfire).
3. Calcium carbide has been released in the furnace building in areas on the 2nd level outside of the control room. Carbide Industries personnel are providing an appropriate response in removing this material and placing it in a secure staging area, pending profiling for disposal.
The OSC demobilized the site at approximately 1250 hrs. on 03/26.
The OSC communicated transfer of lead agency role to KDEP to all parties by email on 03/30
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