# NTSB Safety Recommendation P-72-055 - **operation:** document - **citation:** P-72-055 - **title:** NTSB Safety Recommendation P-72-055 - **source type:** guidance - **agency:** National Transportation Safety Board - **status:** guidance - **official:** true - **published on:** 1972-11-22 - **effective on:** 1972-11-22 - **summary:** THE NTSB RECOMMENDS THAT: THE WASHINGTON GAS LIGHT COMPANY DEVELOP A SECTIONALIZING DISTRIBUTION SYSTEM SO THAT PREPLANNED PROCEDURES ARE AVAILABLE TO ISOLATE ANY SECTION OF ITS SYSTEM IN AN EMERGENCY. - **machine formats:** - **json:** https://regulus.evalyn.ai/document/ntsb-recommendation-p-72-055.json - **markdown:** https://regulus.evalyn.ai/document/ntsb-recommendation-p-72-055.md - **app url:** https://regulus.evalyn.ai/document/ntsb-recommendation-p-72-055 - **source url:** https://data.ntsb.gov/carol-main-public/sr-details/P-72-055 **body:** NTSB safety recommendation P-72-055. THE NTSB RECOMMENDS THAT: THE WASHINGTON GAS LIGHT COMPANY DEVELOP A SECTIONALIZING DISTRIBUTION SYSTEM SO THAT PREPLANNED PROCEDURES ARE AVAILABLE TO ISOLATE ANY SECTION OF ITS SYSTEM IN AN EMERGENCY. Priority: CLASS II Overall Status: Closed - Acceptable Action Issued Date: 1972-11-22 Adopted Date: 1972-11-22 Overall Date Closed: 1986-12-18 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. Ntsbnumber: PLD72XR002 Report Number: PAR-72-04 Addressee Name: Washington Gas Addressee Status: Closed - Acceptable Action Addressee Date Closed: 1986-12-18 Addressee Organization Type: P-Private Industry Communication Date: 1986-09-24 Communication Type: Official Correspondence Communication Contents: THIS ACTUALLY IS A FOLLOWUP AND A HISTORY OF PREVIOUS CORRESPONDENCE: A 2/9/73 LETTER FROM THE WASHINGTON GAS LIGHT COMPANY COMMENTING ON THE BOARD'S REPORT. THIS LETTER DOES NOT RESPOND TO THE BOARD'S RECOMMENDATIONS. Addressee Organization Type: P-Private Industry Communication Date: 1986-10-14 Communication Type: Official Correspondence Communication Contents: BOTH RECOMMENDATION OF THE NTSB WERE ACCEPTED BY WGL WITH FULL IMPLEMENTATION COMPLETED IN 1979. THE FOLLOWING POINTS HIGHLIGHT SOME OF THE FACTORS OF THE VALVE SECTIONALIZATION PROGRAM. 1) APPROXIMATELY 2400 SECTIONS COVERING THE ENTIRE HIGH PRESSURE SYSTEM HAVE BEEN PLANNED AND VERIFIED. AN AVERAGE OF FOUR VALVES CONTROLS EACH SECTION. 2) EACH SECTION VALVE (APPROXIMATELY 5000 VALVES) IS IDENTIFIED IN THE FIELD BY A LENGTH OF PLASTIC PIPE INSIDE EACH VALVE BOX LABELED WITH THE VALVE NUMBER. THESE VALVES ARE INSPECTED ANNUALLY TO CONFIRM THAT THEY ARE PROPERLY IDENTIFIED AND OPERATIONAL. 3) ALL OPERATING PERSONNEL ASSIGNED TO RADIO VEHICLES ARE EQUIPPED AND TRAINED TO OPERATE VALVES IN AN EMERGENCY. 4) A MINIMUM OF SIX SECTION SHUTDOWNS ARE CRITIQUED ANNUALLY TO EVALUATE THAT PROCEDURES ARE BEING FOLLOWED. AT LEAST THREE OF THESE SECTION SHUTDOWNS WILL BE SIMULATIONS. THESE UNANNOUNCED SIMULATIONS ARE USED TO EVALUATE THE READINESS OF EMERGENCY RESPONSE AND SUPPORT PERSONNEL. ALSO INCLUDED FOR YOUR REVIEW IS EMERGENCY PROCEDURE 3, "SECTION SHUTDOWN." THIS PROCEDURE IS INCLUDED IN THE TRANSMISSION AND DISTRIBUTION DEPARTMENT'S OPERATING INSTRUCTIONS. YOUR LETTER ALSO MADE REFERENCE TO P-79-40 WHICH RECOMMENDED THAT THE "MISS UTILITY" ONE-CALL SYSTEM BE IMPLEMENTED IN THE DISTRICT OF COLUMBIA. THE IMPLEMENTATION OF THE MISS UTILITY PROGRAM IN THE DISTRICT OF COLUMBIA OCCURRED ON 9/1/81, UNDER D.C. CODE 43-1701. Addressee Organization Type: P-Private Industry Communication Date: 1986-12-18 Communication Type: Official Correspondence Addressee Organization Type: P-Private Industry Communication Date: 1986-09-24 Communication Type: Official Correspondence - **truncated:** false - **body characters:** 3434