NTSB Safety Recommendation P-83-012

NTSB safety recommendation P-83-012.

THE NTSB RECOMMENDS THAT THE NORTHERN NATURAL GAS COMPANY: REVISE ITS PROCEDURES TO REQUIRE THAT EMPLOYEES PERFORMING EXCAVATION INSPECTION WORK NEAR COMPANY FACILITIES BE FULLY INFORMED AS TO THE LOCATION, DEPTH, AND CHANGE IN DEPTH OF THESE FACILITIES AND TO REMAIN ON THE JOB UNTIL ALL EXCAVATION ACTIVITIES ARE WELL CLEAR OF COMPANY FACILITIES.

Priority: CLASS II

Overall Status: Closed - Acceptable Action

Issued Date: 1983-06-13

Adopted Date: 1983-05-17

Overall Date Closed: 1995-06-20

Synopsis: ON NOVEMBER 4, 1982, A TILE PLOW INSTALLING FIELD DRAINAGE TILE ON A FARM LOCATED 4 MILES WEST OF HUDSON, IOWA, STRUCK AND PUNCTURED A WELL MARKED, 20-INCH-DIAMETER NATURAL GAS TRANSMISSION PIPELINE, NATURAL GAS ESCAPING AT ABOUT 820 PSIG IGNITED IMMEDIATELY, AND THE ENSURING FIRE KILLED FIVE PERSONS, DESTROYED FIVE PIECES OF EXCAVATON MACHINERY AND TWO PICKUP TRUCKS, AND BURNED SEVERAL ACRES OF SOYBEAN STUBBLE.

Probable Cause: The probable cause was the contractor’s decision to change the planned tile installation route without notifying Northern Natural Gas, combined with Northern’s maintenance employee leaving the job site before excavation activities near the pipelines were complete, which allowed the tile plow to strike and puncture the pipeline.

Ntsbnumber: DCA83MP004

Report Number: PAR-83-02

Addressee Name: Northern Natural Gas Company

Addressee Status: Closed - Acceptable Action

Addressee Date Closed: 1995-06-20

Addressee Acronym: NNG

Addressee Organization Type: P-Private Industry

Communication Date: 1995-06-20

Communication Type: Official Correspondence

Communication Contents: THE BOARD NOTES THAT THE ENRON NORTHERN NATURAL GAS COMPANY OPERATING PROCEDURES MANUAL REQUIRES PIPELINES TO BE LOCATED & MARKED IN AREAS WHERE EXCAVATION ACTIVITIES WILL OCCUR & TO ADVISE THE OUTSIDE PARTY OF THE DEPTH OF THE PIPELINE. BASED ON THIS INFO, P-83-12 HAS BEEN CLASSIFIED "CLOSED--ACCEPTABLE ACTION."

Addressee Acronym: NNG

Addressee Organization Type: P-Private Industry

Communication Date: 1983-08-08

Communication Type: Official Correspondence

Communication Contents: NORTHERN NATURAL GAS COMPANY LETTER: WE BELIEVE NOTHERN'S CURRENT PROCEDURES RESULT IN EMPLOYEES BEING FULLY INFORMED OF THE INFORMATION NECESSARY TO SUPERVISE A SAFE CROSSING. IF A PIPELINE CROSSING IS TO BE MADE, THE EMPLOYEE ALSO DETERMINES THE DEPTH. THE EMPLOYEE IS INFORMED OF THE LOCATION AND DEPTH IN THE MOST ACCURATE AND RELIABLE WAY POSSIBLE, INVESTIGATING THE ACTUAL CONDITIONS. THE CHANGE IN DEPTH OF PIPELINES IS NOT ROUTINELY DETERMINED BECAUSE IT IS OF NO VALUE FOR CROSSINGS. THE CRITICAL DEPTH IS THE ONE AT THE POINT OF CROSSING. THE MEANING OF THE PHRASE "WELL CLEAR" IS SUBJECTIVE, BUT CONSIDERING THE CIRCUMSTANCES OF THE HUDSON INCIDENT, WE ASSUME THAT MORE EXTENDED SUPERVISION IS BEING SUGGESTED THAN THAT WHICH OCCURRED THERE. HOWEVER, BY NORTHERN'S INTERPRETATION, THE EXCAVATION AT HUDSON WAS "WELL CLEAR" OF THE PIPELINE WHEN THE INSPECTOR LEFT, AND REMAINING WORK WOULD NOT HAVE ENDANGERED PERSONS ON THE PIPELINE. NORTHERN'S EXISTING PROCEDURES DEMONSTRATE THAT IT HAS ALWAYS RECOGNIZED THE NEED TO SUPERVISE EXCAVATIONS. NORTHERN HAS PUT IN PLACE ON A PORTION OF ITS SYSTEM A TRIAL POLICY WHICH REQUIRES A COMPANY INSPECTOR TO BE PRESENT FOR ANY EXCAVATION OR BACKFILLING THAT OCCURS WITHIN FIFTY (50) FEET OF A PIPELINE. AFTER EVALUATION OF THE TRIAL, THE POLICY MAY BE ADOPTED THROUGHOUT THE COMPANY.

Addressee Acronym: NNG

Addressee Organization Type: P-Private Industry

Communication Date: 1995-03-23

Communication Type: Official Correspondence

Communication Contents: THE ENRON GAS PIPELINE OPERATING COMPANY-OPERATING PROCEDURES PROGRAM ESTABLISHED A DAMAGE PREVENTION PROGRAM TO PREVENT DAMAGE TO COMPANY GAS FACILITIES IN THE VICINITY OF EXCAVATION ACTIVITIES. THIS PROCEDURE HELPS SATISFY THE REQUIREMENTS OF DOT REGULATION 192.614. IT ALSO SATIFIES PERTINENT STATE STATUES FOR INTRASTATE & NONJURISDICTIONAL GATHERING PIPELINE PERTAINING TO EXCAVATION ACTIVITIES.

Addressee Acronym: NNG

Addressee Organization Type: P-Private Industry

Communication Date: 1984-01-09

Communication Type: Official Correspondence