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Safety Recommendation Details

Safety Recommendation P-04-009
Synopsis: On April 7, 2003, about 8:55 p.m., central daylight time, an 80,000-barrel storage tank at the ConocoPhillips 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.
Recommendation: The National Transportation Safety Board makes the following safety recommendations to ConocoPhillips Company: Revise your storage tank operating procedures to include instructions for minimizing the possibility of creating a flammable atmosphere and the occurrence of a static discharge inside a tank after a floating roof has been either intentionally or unintentionally landed, especially for tanks where switch loading is likely to occur.
Original recommendation transmittal letter: PDF
Overall Status: Closed - Acceptable Action
Mode: Pipeline
Location: Glenpool, OK, United States
Is Reiterated: No
Is Hazmat: No
Accident #: DCA03MP001
Accident Reports:
Storage Tank Explosion and Fire
Report #: PAR-04-02
Accident Date: 4/7/2003
Issue Date: 11/4/2004
Date Closed: 4/27/2005
Addressee(s) and Addressee Status: ConocoPhillips Company (Closed - Acceptable Action)

Safety Recommendation History
From: NTSB
To: ConocoPhillips Company
Date: 4/27/2005
Response: The Safety Board notes that ConocoPhillips has revised its storage tank operating policies and procedures to minimize the chances of a flammable atmosphere being created and a static discharge occurring inside a tank after the floating roof has landed. Specifically, ConocoPhillips (1) has restricted switch loading at its facilities, and requires a specific safety plan for those times when switch loading can not be avoided due to unanticipated operating conditions, (2) has implemented a management of change process for filling and emptying tanks, (3) requires operators to verify that loose objects have been removed or secured inside a tank before it is returned to service after maintenance, (4) requires that the initial fill of tanks are postponed during electrical storms, and (5) requires that the pumping of substantial amounts of air into a storage tank be avoided wherever possible. Accordingly, because ConocoPhillips has revised its operating procedures as recommended, Safety Recommendation P-04-9 is classified "Closed--Acceptable Action."

From: ConocoPhillips Company
Date: 2/2/2005
Response: Letter Mail Controlled 2/7/2005 3:09:33 PM MC# 2050046 ConocoPhillips, Pipelines and Terminals Response: The below have been addressed in policies or procedures. · Switch loading of tanks is not an allowed operating practice at our facilities. If switch loading cannot be avoided due to unanticipated conditions, a specific plan for purging with nitrogen or other inert gas will be followed in accordance with our MOC policy. (Implemented Policy in May, 2004). · Implementation of a Management of Change (MOC) process for emptying tanks and refilling tanks (May 2004) · Verification that loose objects have been removed or secured inside of tank before returning to service after maintenance (May 2003, Section 4.5.2e) · Avoid initial fill during electrical storms · Avoid pumping substantial amounts of air into tank (API 2003 Section 4.5.2f) If your or members of the Safety Board have questions or comments, please feel free to contact Randy Beggs at 580-767-7101 to discuss further. Sincerely: Linus J. Schmitz, Manager, Pipeline Integrity & Reliability.