NTSB Safety Recommendation Letter P-80-054 through P-80-055

Page 1Official PDFWASHINGTON, D.C. ISSUED: June 2 3 , 1980 Administrator Research and SDecial Programs - ( SAFETY RECOMMENDAT ION ( S ) Administration P-80-54 and -55 i - U.S. Department of Transportation Washington, D.C. 20590 At 1 D : l Z a.m., c.d.t.,, on October 24, 1979, an explosion and fire destroyed the Greene County Clerk's offlce building and the adjoining Greene County Courthouse, gutted a connecting building which was under construction, and damaged nearby buildings in Stanardsville, Virginia. Thirteen persons were injured and the property damage was extensive. - 1/ The Safety Board's investigation revealed that natural gas had leaked from a break in a 1 1/4-inch-diameter, coated, steel service line, which had been snagged by a backhoe that was being used to dig a footing for an addition to the county clerk's office building. The construction contractor, owner of the backhoe, was working for Greene County. The backhoe bucket hit the service line and pulled it about 3 inches out of the building wall. The tension on the pipe a t the gas meter caused the pipe to crack at an elbow which connected the gas meter to a valve located inside the wall. An excess flow valve 2/ was not installed on the service line, so the rapid release of natural gas into the basement was not prevented. An excess flow valve closes automatically when the gas flow through the valve reaches or exceeds a predetermined flow rate. If an excess flow valve had been installed on the service line at Stanardsville, the gas flow would have been shut off when the service line was ruptured and this accident would have been prevented. - 1/ For more detailed information read, "Pipeline Accident Report--Columbia Gas of Virginia, Inc., Explosion and Fire, Stanardsville, Virginia, October 24, 1979" (NTSB-PAR-80-3). - 2/ An excess flow valve is a safety device usually installed a t the intersection of the service line with the main line. The valve automatically and immediately will shut off gas flow at the main in the event of a service line rupture, preventing hazardous blowing of gas and preventing loss of pressure in the main until repairs are made and service line pressure restored. 2857B#

Page 2-2- The Safety Board pointed out the value of excess flow valves in a 1971 s study. 31 The Safety Board also discussed this need in its accident report on the rupture of a service line in Lake City, Minnesota, on October 30, 1972,4/ and in its accident report on the rupture of a servic? line in New York City, on April22, 1974. 5/ In both reports the Safety Board noted that the use of an excess flow valve might have shut off the flow of natural gas after the service lines were ruptured and the resultant explosions and loss of life and property might have been averted or their severity reduced. The Safety Board has twice recommended that the Materials Transport Bureau (MTB) of the U.S. Department of Transportation develop standards for the ra shutdown of failed pipelines and to study fail-safe devices to stop the flow of natur from ruptured lines. As a result of these recommendations, the MTB contracted study on the "Rapid Shutdown of Failed Pipeline Systems and Limiting of Pressure to Prevent Pipeline Failure Due to Over Pressure." The study, completed in October 1974, concluded that excess flow valves would improve safety, that they are available and technically feasible, and that they are economically feasible. The MTB is still reviewin the matter to determine what regulatory action it may take. The service line was operated at 15-psig pressure and was buried under approximately 24 inches of cover. This line was connected to the gas main with a weld-on tapping tee and extended from the main, located under the street pavement, to the inlet side of a valve at the curb, and from there to the inlet side of the customer's meter. The original service line had been replaced in 1962, and the segment from the curb valve t the indoor meter, about 20 feet, was considered by Columbia Gas of Virginia, Inc., (gas company) to be a customer's line and not its responsibility. Title 49 CFR 192.3 defines "service line" as "a distribution line that transports gas from a common source of suppl to (a) a customer's meter or the connection to a customer's piping, whichever is farth downstream, or (b) the connection to a customer's piping if there is no customer meter." - 61 The investigation disclosed that Greene County authorities did not invite the g company to progress meetings on the construction project or to meet onsite with them specify which lines might be subjected to damage. At the time of the accident, a "one call" system was not in operation in Greene County, although a system was in use in th adjacent counties of Madison and Culpeper and in other Virginia counties. Approximate1 44 of the 90 Virginia counties are using the "one-call" notification system at this time. The most effective method of preventing excavation-caused damage underground facilities is to notify the operators of utility companies in advance of proposed excavation work to allow the operators to mark the location of their facili before excavation begins. The most efficient and convenient method for excavators to - 31 "Special Study--Effects of Delay in Shutting Down Failed Pipeline Systems and Methods of Providing Rapid Shutdown" (NTSB-PSS-71-1). - 41 "Pipeline Accident Report--Northern States Power Company, Lake City, Min October 30, 1972" (NTSB-PAR-73-1). - 51 "Pipeline Accident Report--Consolidated Edison Company, Explosion at Street, New York, New York, April 22, 1974" (NTSB-PAR-76-2). - 6 1 A customer meter is the meter that measures the transfer of gas from an operator t consumer.#

Page 3-3- make this notification is through a "one-call" system. A "one-call" system establishes a center to which an excavator can make one telephone call to effect notification to all participating underground facility operators of the date and location of a proposed excavation project. The center alerts each operator so that each of their underground facilities near the work area can be located and marked. There are now 106 "one-call" systems operating in 41 States. Some systems provide Statewide coverage. In a 1978 special study, I / the Safety Board reported that a 1977 survey of "one-call" systems found a markedly downward trend in damage to underground facilities after the "one-call" systems were established. The greatest number of accidents to underground facilities after the "one-call" was established was attributed to excavators who did not notify the operators of underground facilities before undertaking excavation. Throughout the country, the "one-call" notification system has been effective in reducing accidents and damage involving underground facilities. As an example, in 1972, the first year that the system was used by the gas, electric, telephone, and water utilities serving the two Maryland counties adjacent to the District of Columbia, there were 2,103 incidents of damage to their underground facilities. During 1976, the last year these statistics were recorded by the "one-call" center, the number of incidents had been reduced by 1,299--a reduction of 61.8 percent. In that same period, "one-call" notifications had increased tenfold. On November 15, 1979, the Materials Transportation Bureau (MTB) of the U.S. Department of Transportation published in the Federal Register a Notice of Proposed Rulernaking (NPRM) to amend 49 CFR Part 192 to require each gas pipeline operator to implement a damage-prevention program. The NPRM shows that the MTB recognizes excavation damage as a major problem and encourages preconstruction meetings, "one-call" systems, and local ordinances to control excavation. The Safety Board on February 11, 1980, commenting on the NPRM, supported the intent of the rulemaking and offered suggestions to improve the proposed rule. On November 30, 1979, Public Law 96-129 amended the National Gas Pipeline Safety Act of 1968. Section 101 of the new law required the Secretary of Transportation, within 12 months, to include in the Federal minimum safety standards a requirement that any operator of pipeline facilities: (A) participate in any public safety program- (i) which provides for notice to pipeline facility operators of proposed demolition, excavation, tunneling, or construction near or affecting such facility; (ii) which requires such operators to identify specific pipeline facilities which may be affected by the proposed demolition, excavation, tunneling, or construction, for the purpose of preventing damage to such facilities; and (iii) which the Secretary determines is being carried out in a manner adequate to assure protection against the hazards to that operator's pipeline facilities created by such demolition, excavation, tunneling, or construction; or (B) to the extent that such a program is not available, take such steps as the Secretary shall prescribe to provide services to the public with respect to that operator's pipeline facilities which are comparable to those which would be available to the public under such a program. - - 7/ "Safe Service Life for Liquid Petroleum Pipelines" (NTSB-PSS-78-1).#

Page 4-4- The gas company was approached by the manager of "Miss Utility," the "one-call" system operating in central Virginia, in the spring of 1978, again in the spring of 1979, and again after the accident, and asked if it would be willing to cooperate in the expansion of the "one-call" notification system into Greene County. The gas company replied that due to the small number of facilities operating in that area, membership was not justifiable at that time. Therefore, as a result of its investigation of this accident, the Nat Transportation Safety Board recommends that the Research and Special Programs Administration of the U.S. Department of Transportation: Expedite final action on rulemaking, docket No. PS-59, concerning damage-prevention programs. (Class n, Priority Action) (P-80-54) Expedite rulemaking to require the installation of excess flow valves on all newly installed or renewed high-pressure gas distribution system service lines. (Class 11, Priority Action) (P-80-55) KING, Chairman, McADAMS and GOLDMAN, Members, concurred in these recommendations. DRIVER, Vice Chairman, and BURSLEY, Member, did not participate.#