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Safety Recommendation Details

Safety Recommendation P-72-053
Details
Synopsis: On March 24, 1972, in the Annandale section of Fairfax County, VA, a contractor's backhoe snagged a 2-inch steel gas main, and pulled the main out of a compression coupling 22 feet away. Gas company personnel arrived on the scene about 40 minutes later and started to search for the break. The gas was not shut off and the nearby houses were not checked for the presence of gas. A house, 240 feet away from the point at which the line was snagged, exploded. Two other houses exploded and burned. As a result of the accident, three persons died and one was injured; two houses were destroyed and a third was badly damaged; and $153,000 worth of property was damaged.
Recommendation: THE NTSB RECOMMENDS THAT: THE AMERICAN GAS ASSOCIATION STUDY THE FLOW OF GAS THROUGH VARIOUS CONSTRUCTION FILL MEDIA AND RECOMMEND METHODS AND TYPES OF FILL TO BE USED IN THE INSTALLATION OF UNDERGROUND UTILITY LINES.
Original recommendation transmittal letter: PDF
Overall Status: Closed - Reconsidered
Mode: Pipeline
Location: Annandale, VA, United States
Is Reiterated: No
Is Hazmat: No
Is NPRM: No
Accident #: 80206
Accident Reports:
Washington Gas Light Company, Natural Gas Explosion
Report #: PAR-72-04
Accident Date: 3/24/1972
Issue Date: 11/22/1972
Date Closed: 1/11/1980
Addressee(s) and Addressee Status: American Gas Association (Closed--No Longer Applicable)
Keyword(s):

Safety Recommendation History
From: NTSB
To: American Gas Association
Date: 1/11/1980
Response:

From: American Gas Association
To: NTSB
Date: 2/12/1973
Response: LETTER FROM AGA: RECOMMENDATION TAKEN UNDER ADVISEMENT BY ASSOCIATION'S OPERATING ENGINEERING SECTION. THEY WILL DETERMINE WHAT NEEDS TO BE DONE AND TAKE APPROPRIATE ACTION. 1/26/78 - AGA LETTER IN RESPONSE TO NTSB 11/9/77 LETTER REQUESTING INFORMATION ON STATUS OF ACTIVITY: A SURVEY OF GAS COMPANIES BY A TASK GROUP SHOWED A MAJORITY DID NOT FAVOR BACKFILL TECHNIQUES THAT WOULD INHIBIT GAS MIGRATION. THE TASK GROUP RECOMMENDED THAT NO FURTHER RESEARCH BE INITIATED ON CONTROLLING UNDERGROUND MIGRATION OF GAS. 8/15/78 - AGA LETTER IN RESPONSE TO NTSB 8/4/78 LETTER REQUESTING RECONSIDERATION: AGA SUBMITTED THIS RECOMMENDATION TO THE OPERATING SECTION DISTRIBUTION CONSTRUCTION AND MAINTENANCE COMMITTEE TOGETHER WITH THE THOUGHTS EXPRESSED IN THE NTSB LETTER. 11/9/79 - AGA LTR: BASED ON AN NTSB LETTER OF AUGUST 4, 1978, THIS RECOMMENDATION WAS RETURNED TO THE AGA COMMITTEE FOR DISTRIBUTION, CONSTRUCTION AND MAINTANANCE FOR FURTHER REVIEW. A REPORT OF THE COMMITTEE WAS ENCLOSED. THE COMMITTEE BELIEVES THAT GAS MIGRATION CANNOT BE PROPERLY CONTROLLED BY BACKFILL TYPE. MORE IMPORTANT CONTROL ITEMS ARE THE INSTALLATION AND MAINTENANCE OF THE FACILITY ALONG WITH CATHODIC PROTECTION SYSTEMS AND LEAK SURVEY MONITORING. PROMPT EMERGENCY ACTION IS ALSO IMPORTANT. CURRENT CONSTRUCTION AND MAINTENANCE PRACTICES SHOULD BE RECOGNIZED AS EFFORTS BEYOND CODE REQUIREMENTS TO MINIMIZE GAS MIGRATION. EXAMPLES ARE: COMPLETE SEALING OF PIPE ENTRY INTO BUILDING, ABOVE GROUND BUILDING ENTRY OF SERVICE OR FUEL LINES, AND MORE THAN MINIMUM REQUIRED LEAK SURVEY FREQUENCY.