P-87-013
P-87-013
NTSB safety recommendation P-87-013.
THE NTSB RECOMMENDS THAT THE WILLIAMS PIPELINE COMPANY: REVISE THE OPERATING PROCEDURES TO PLACE GREATER EMPHASIS ON ISOLATING SECTIONS OF ITS PIPELINES IN THE EVENT OF A FAILURE, AND TRAIN EMPLOYEES ON THE PROCEDURES ESTABLISHED.
Priority: CLASS II
Overall Status: Closed - Acceptable Action
Issued Date: 1987-09-09
Adopted Date: 1987-07-20
Overall Date Closed: 1990-11-19
Synopsis: ABOUT 4:20 A.M. ON JULY 8, 1986, LINE 2N, AN 8-INCH PRODUCTS PIPELINE OPERATED BY WILLIAMS PIPE LINE COMPANY (WPL) AT MOUNDS VIEW, MINNESOTA, RUPTURED. UNLEADED GASOLINE UNDER 1,434 PSIG SPEWED FROM A 7 1/2-FOOT-LONG OPENING ALONG THE LONGITUDINAL SEAM OF THE PIPE. VAPORIZED GASOLINE COMBINED WITH AIR AND LIQUID GASOLINE FLOWED ALONG NEIGHBORHOOD STREETS. ABOUT 20 MINUTES LATER, THE GASOLINE VAPOR WAS IGNITED WHEN AN AUTOMOBILE ENTERED THE AREA. FOLLOWING AN EXPLOSION-LIKE NOISE, FIRE SPREAD RAPIDLY ALONG THE PATH OF THE LIQUID GASOLINE. TWO PERSONS WERE BURNED SEVERELY AND LATER DIED, AND ONE PERSON SUFFERED SERIOUS BURNS. THERE WAS SUBSTANTIAL PROPERTY DAMAGE AND SOIL AND WATER POLLUTION.
Ntsbnumber: DCA86AP014
Report Number: PAR-87-02
Addressee Name: Williams Pipeline Company
Addressee Status: Closed - Acceptable Action
Addressee Date Closed: 1990-11-19
Addressee Organization Type: P-Private Industry
Communication Date: 1989-02-09
Communication Type: Official Correspondence
Communication Contents: FOR MANY YEARS, WILLIAMS HAS HAD AN EXTENSIVE TRAINING PROGRAM FOR HOURLY, TECHNICAL, AND SUPERVISORY FIELD EMPLOYEES. THESE TRAINING PROGRAMS INCLUDED RECOGNIZING AND ANALYZING ABNORMAL CONDITIONS AND EMERGENCY RESPONSES. HOWEVER, IN LIGHT OF THE PIPELINE INDUSTRY AND WILLIAMS' EXPERIENCES IN THE LAST SEVERAL YEARS, WILLIAMS IS PURSUING NUMEROUS ENHANCEMENTS TO ITS TRAINING PROGRAMS, INCLUDING THOSE COMPONENTS PERTAINING TO ABNORMAL CONDITIONS AND EMERGENCY RESPONSES (SEE RESPONSE TO P-87-16 & 17). WILLIAMS' OPERATING AND MAINTENANCE MANUAL HAS BEEN REVISED TO STATE THAT WHEN THE ORIGIN OF A POSSIBLE LEAK IS NOT KNOWN, URBAN AREAS ALONG THE ROUTE OF THE PIPELINE SEGMENT CONTAINING THE PROBABLE ORIGIN OF THE LEAK SHALL BE INSPECTED FIRST PURSUANT TO A LOGICAL SEQUENCE FOR TRAVEL. WILLIAMS HAS IMPLEMENTED A COMPUTERIZED PROGRAM (DEVELOPMENT BEGAN IN 1982) WHICH WILL ASSIST THE DISPATCHER IN LOCATING THE ORIGIN OF A LEAK SITE AND THEREBY FACILITATING SELECTION OF THE APPROPRIATE ISOLATION VALVES TO CLOSE (SEE RESPONSE TO P-87-19).
Addressee Organization Type: P-Private Industry
Communication Date: 1989-10-10
Communication Type: Official Correspondence
Communication Contents: WPL'S OPERATING AND EMERGENCY PROCEDURES MANUALS (COPIES WERE EARLIER PROVIDED TO THE NTSB DURING THE ACCIDENT INVESTIGATION) OUTLINE ACTION STEPS FOR PROPERLY ISOLATING A SECTION OF LINE DURING AN EMERGENCY. AN EXCERPT FROM OUR OPERATING MANUAL DETAILING ADDITIONAL REVISED INSTRUCTIONS FOR LOCATING A SUSPECT LEAK IS ATTACHED AS EXHIBIT #1. AS INDICATED IN OUR EARLIER RESPONSE, A SERIES OF COMPUTER BASED TRAINING MODULES DEDICATED SOLELY TO EMERGENCY PREPAREDNESS AND RESPONSE, ARE CURRENTLY UNDER DEVELOPMENT. THESE MODULES, AMONG OTHER SUBJECTS, WILL ADDRESS PIPELINE ISOLATION. OUR PREVIOUS RESPONSES TO P-87-13 AND -19 BOTH DESCRIBE OUR RECENTLY IMPLEMENTED (1-89) SUPERVISORY CONTROL DATA ACQUISITION (SCDA) SYSTEM WHICH WILL FURTHER ASSIST A DISPATCHER IN LOCATING THE ORIGIN OF A LEAK SITE AND IN DETERMINING THE APPROPRIATE VALVES TO CLOSE. THIS NEW SYSTEM WAS NOT IN PLACE AT THE TIME OF THE ACCIDENT; CONSEQUENTLY, NTSB RECENT STATEMENTS LABELING THESE SYSTEMS AS INADEQUATE BASED UPON RESPONSE TIMES DURING THE 1986 ACCIDENT, ARE INAPPROPRIATE.
Addressee Organization Type: P-Private Industry
Communication Date: 1990-08-14
Communication Type: Official Correspondence
Communication Contents: IN EVENT OF A SUSPECTED LEAK, WPL PROCEDURES INSTRUCT PERSONNEL TO SHUT DOWN & ISOLATE THE PIPELINE SECTION IN QUESTION. THIS ISOLATION INVOLVES THE CLOSING OF APPROPRIATE REMOTE MOTOR-OPERATED VALVES (MOVS) AS WELL AS MANUAL VALVES ON EITHER SIDE OF THE SUSPECTED LEAK AREA. THE REMOTE MOVS ARE CLOSED BY DISPATCHING & ARE LOCATED AT TERMINAL & STATION FACILITIES & OTHER STRATEGIC LOCATIONS ALONG OUR PIPELINES. FURTHER ISOLATION OF THE LEAK AREA IS ACCOMPLISHED WITH FIELD CREWS BY CLOSING APPROPRIATE MANUAL ISOLATION VALVES WHICH ARE LOCATED ON APPROXIMATELY 10 MILE SPACINGS ALONG THE MAINLINE. THESE ISOLATION PROCEDURES WHERE IN EFFECT PRIOR TO THE 1986 ACCIDENT AT MOUNDS VIEW, AND WERE CONTAINED IN THE OPERATING MANUAL (SECTION 1) SUBMITTED PREVIOUSLY. TO FURTHER ADDRESS THE BOARD'S CONCERNS, HOWEVER, WE HAVE MADE SOME REVISIONS TO THESE PROCEDURES. AS MENTIONED IN OUR EARLIER RESPONSE, TRAINING REGARDING LINE ISOLATION PROCEDURES IS ADDRESSED IN THE 5 CBT MODULE SERIES ON EMERGENCY RESPONSE.
Addressee Organization Type: P-Private Industry
Communication Date: 1990-07-05
Communication Type: Official Correspondence
Addressee Organization Type: P-Private Industry
Communication Date: 1990-11-19
Communication Type: Official Correspondence
Addressee Organization Type: P-Private Industry
Communication Date: 1989-07-12
Communication Type: Official Correspondence
This material provides agency context. It does not replace binding regulatory text, and its legal effect depends on the underlying authority and facts.