Pipeline Accident Report

Storage Tank Explosion and Fire

Glenpool, Oklahoma
April 7, 2003

NTSB Number PAR-04-02
NTIS Number PB2004-916502

Executive Summary:

On April 7, 2003, at about 8:55 p.m., central daylight time, an 80,000-barrel storage tank at ConocoPhillips Company’s Glenpool South tank farm in Glenpool, Oklahoma, exploded and burned as it was being filled with diesel. The tank, designated tank 11, had previously contained gasoline, which had been removed from the tank earlier in the day. The tank contained between 7,397 and 7,600 barrels of diesel at the time of the explosion. The resulting fire burned for about 21 hours and damaged two other storage tanks in the area. The cost of the accident, including emergency response, environmental remediation, evacuation, lost product, property damage, and claims, was $2,357,483. There were no injuries or fatalities. Nearby residents were evacuated, and schools were closed for 2 days.

Probable Cause

The National Transportation Safety Board determines that the probable cause of the April 7, 2003, storage tank explosion and fire in Glenpool, Oklahoma, was ignition of a flammable fuel-air mixture within the tank by a static electricity discharge due to the improper manner in which ConocoPhillips Company conducted tank operations. Contributing to the extent of the property damage and the magnitude of the impact on the local community was the failure of American Electric Power employees to recognize the risk the tank fire posed to the nearby power lines and take effective emergency action.

The safety issues identified during the investigation of this accident are as follows:


As a result of its investigation of this accident, the National Transportation Safety Board makes safety recommendations to the Research and Special Programs Administration, ConocoPhillips Company, American Electric Power, the American Society of Mechanical Engineers, and the Institute of Electrical and Electronics Engineers.