NTSB Safety Recommendation P-00-021

NTSB safety recommendation P-00-021.

THE NTSB RECOMMENDS THAT RSPA: EVALUATE, DURING ANNUAL INSPECTIONS OF UTILITIES, THE ADEQUACY OF OPERATOR EMERGENCY PLANS AND WRITTEN PROCEDURES FOR RESPONDING TO GAS PIPELINE EMERGENCIES, PAYING PARTICULAR ATTENTION TO PROCEDURES THAT ADDRESS THE POSSIBLE MIGRATION OF GAS FROM EXCAVATION SITES INTO NEARBY BUILDINGS. IF WARRANTED, REQUIRE THAT OPERATORS MODIFY THE PROCEDURES.

Priority: CLASS II

Overall Status: Closed - Acceptable Action

Issued Date: 2000-12-15

Adopted Date: 2000-12-07

Overall Date Closed: 2002-06-28

Synopsis: ON 1/22/99, WHILE DIGGING A TRENCH BEHIND A BUILDING AT 406 ALABAMA AVENUE, A BACKHOE OPERATOR DAMAGED A 3/4-INCH STEEL NATURAL GAS SERVICE LINE AND 1-INCH WATER SERVICE LINE, BOTH OF WHICH WERE UNDERGROUND. THIS RESULTED IN TWO LEAKS IN THE NATURAL GAS SERVICE LINE, WHICH WAS OPERATED AT 35 PSIG. ONE LEAK OCCURRED WHERE THE BACKHOE BUCKET HAD CONTACTED AND PULLED THE NATURAL GAS SERVICE LINE. THE OTHER WAS A PHYSICAL SEPARATION OF THE GAS SERVICE LINE AT AN UNDERGROUND JOINT NEAR THE METER, WHICH WAS CLOSE TO THE BUILDING. GAS MIGRATED INTO THE BUILDING AT 406 ALABAMA AVENUE, WHERE IT IGNITED ABOUT 10:02 A.M. AN EXPLOSION FOLLOWED, DESTROYING THREE BUILDINGS: 404, 406, AND 408 ALABAMB AVENUE. OTHER BUILDINGS WITHIN A TWO-BLOCK AREA OF THE EXPLOSION WERE SIGNIFICANTLY DAMAGED. THREE FATALITIES, FIVE SERIOUS INJURIES, AND ONE MINOR INJURY RESULTED FROM THIS ACCIDENT. THE NATIONAL TRANSPORTATION SAFETY BOARD DETERMINED THAT THE PROBABLE CAUSE OF THE ACCIDENT WAS THE FAILURE OF R&B CONSTRUCTION (R&B) TO ESTABLISH AND FOLLOW SAFE PROCEDURES FOR EXCAVATION ACTIVITIES, RESULTING IN DAMAGE TO A 3/4-INCH GAS SERVICE LINE, AND THE FAILURE OF THE UTILITIES BOARD OF THE CITY OF BRIDGEPORT (UTILITIES BOARD) TO PROVIDE APPROPRIATE EMERGENCY RESPONSE TO THE SUBSEQUENT NATURAL GAS LEAK.

Probable Cause: The National Transportation Safety Board determined that the probable cause of the accident was the failure of R&B Construction (R&B) to establish and follow safe procedures for excavation activities, resulting in damage to a 3/4-inch gas service line, and the failure of the Utilities Board of the City of Bridgeport (Utilities Board) to provide appropriate emergency response to the subsequent natural gas leak.

Ntsbnumber: DCA99MP004

Report Number: PAB-00-01

Addressee Name: RSPA

Addressee Status: Closed - Acceptable Action

Addressee Date Closed: 2002-06-28

Addressee Acronym: RSPA

Addressee Organization Type: G-Federal Government

Communication Date: 2002-06-28

Communication Type: Official Correspondence

Communication Contents: In April 2001, RSPA advised the Safety Board that the Office of Pipeline Safety inspection forms were being revised to ensure that an inspector reviews an operator's plan for procedures that address possible multiple gas leak sites and migration of gas from line breaks into buildings. If a gas pipeline operator's emergency plans did not adequately address these issues, RSPA would require the operator to amend its procedures. RSPA now reports that its state pipeline safety program monitoring form was changed in 2000 and updated in 2001 to ensure that state pipeline inspectors, who inspect most local gas distribution operators, check to ensure that emergency response procedures adequately address possible multiple leaks and gas migration into buildings. Accordingly, Safety Recommendation P-00-21 is classified "Closed--Acceptable Action."

Addressee Acronym: RSPA

Addressee Organization Type: G-Federal Government

Communication Date: 2001-07-06

Communication Type: Official Correspondence

Communication Contents: The Safety Board is pleased to note that all OPS inspectors have been advised of the cause of the Bridgeport accident and will be briefed on the content of the Advisory Bulletin. Also, the OPS inspection forms are currently being reviewed to ensure that an inspector reviews an operator's plan for procedures that address possible multiple gas leak sites and migration of gas from line breaks into buildings. If a gas pipeline operator's emergency plans do not adequately address these issues, RSPA will require the operator to amend its procedures. Accordingly, pending further response from RSPA on the completion of this initiative, Safety Recommendation P-00-21 is classified "Open-Acceptable Response."

Addressee Acronym: RSPA

Addressee Organization Type: G-Federal Government

Communication Date: 2002-04-17

Communication Type: Official Correspondence

Communication Contents: Letter Mail Controlled 04/30/2002 7:02:52 PM MC# 2020436 RSPA changed its State pipeline safety program monitoring form to ensure that state pipeline inspectors, who inspect most local gas distribution operators, check that emergency response procedures adequately address possible multiple leaks and gas migration into buildings. The annual form was revised in CY 2000 and updated in CY 2001 to specifically refer to the NTSB.

Addressee Acronym: RSPA

Addressee Organization Type: G-Federal Government

Communication Date: 2001-04-12

Communication Type: Official Correspondence

Communication Contents: Letter Mail Controlled 04/23/2001 2:57:19 PM MC# 2010341 RSPA changed its State pipeline safety program monitoring form to ensure in their annual reviews of operator programs that state pipeline safety inspectors, who inspect most local gas distribution operators, check that emergency response procedures adequately address possible multiple leaks and gas migration into buildings. All OPS inspectors have been advised of the cause of the Bridgeport accident and will be briefed on the content of the Advisory Bulletin. Also, the OPS inspection forms are currently being reviewed to ensure that an inspector reviews an operator's plan for procedures that address possible multiple gas leak sites and migration of gas from line breaks into buildings. If a gas pipeline operator's emergency plans do not adequately address these issues, we will require the operator to amend its procedures.