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Safety Recommendation Details

Safety Recommendation P-70-040
Details
Synopsis: ON NOVEMBER 6, 1969, DURING A HIGHWAY CONSTRUCTION PROJECT IN BURLINGTON, IOWA, A BULLDOZER WEIGHING 70,000 POUNDS DROVE OVER AND PARTIALLY COLLAPSED THE STEEL COVERS OF A GAS REGULATOR PIT, DAMAGING THE REGULATOR. WHILE THE PRESSURE WAS PARTIALLY CONTROLLED BY A MONITORING OR SAFETY REGULATOR, GAS, REPORTEDLY AT FOUR TO FIVE TIMES THE NORMAL OPERATING PRESSURE, ENTERED THE DISTRIBUTION SYSTEM. GAS CUSTOMERS IN THE AFFECTED AREA STARTED REPORTING HIGH GAS PILOTS AND FIRES TO ISU AND THE FIRE DEPARTMENT. THE HIGH-PRESSURE GAS SOURCE WAS TURNED OFF BUT FIRES CONTINUED TO BE REPORTED, THE FIRES WROUGHT MAJOR DAMAGE TO THE INTERIORS OF 10 HOUSES AND MINOR DAMAGE TO KITCHENS AND APPLIANCES IN 42 OTHERS. PROPERTY DAMAGE WAS ESTIMATED AT $80,000.
Recommendation: THE NTSB RECOMMENDS THAT IOWA SOUTHERN UTILITIES, INC., TAKE THE FOLLOWING ACTION: DEVELOP A WRITTEN, COMPREHENSIVE REGULATOR MAINTENANCE AND TESTING PROCEDURE TO ASSURE PROPER OPERATION DURING NORMAL USE AND IN THE EVENT OF EMERGENCIES, PENDING ANY GOVERNMENT-ORIGINATED REQUIREMENTS. APPROPRIATE RECORDS OF MAINTENANCE WORK PERFORMED SHOULD BE MADE.
Original recommendation transmittal letter: PDF
Overall Status: Closed - Acceptable Action
Mode: Pipeline
Location: Burlington, IA, United States
Is Reiterated: No
Is Hazmat: No
Is NPRM: No
Accident #: DCA70MP001
Accident Reports:
Low Pressure Natural Gas Distribution System
Report #: PAR-70-01
Accident Date: 11/6/1969
Issue Date: 10/14/1970
Date Closed: 7/20/1976
Addressee(s) and Addressee Status: Iowa Southern Utilities, Inc. (Closed--No Longer Applicable)
Keyword(s):

Safety Recommendation History
From: Iowa Southern Utilities, Inc.
To: NTSB
Date: 7/7/1971
Response: THE BOARD WAS INFORMED BY LETTER THAT THE FOLLOWING ACTION HAS BEEN TAKEN: A REGULATOR STATION INSPECTION PROCEDURE HAS BEEN WRITTEN AND SUBMITTED TO THE BOARD. CORRESPONDENCE DOCUMENTATION INCOMPLETE.

From: NTSB
To: Iowa Southern Utilities, Inc.
Date: 6/2/1971
Response: