NTSB Safety Recommendation Letter P-84-011 through P-84-012

Page 1Official PDFNATIONAL TRANSPORTATION SAFETY BOARD WASHINGTON, D.C. I S S U E D : June 15, 1984 Mr. Douglas H. Buswell President and Chief Executive Officer Interstate Power Company SAFETY RECOMMENDATION(S) 100 Main Street Dubuque, Iowa 52001 P-84-11 and -12 A t 1195 a.m., c.d.t., on July 12, 1983, natural gas escaping under 60 pounds pressure from a crack in a butt fusion joint in a 2-inch plastic gas main entered an apartment building in Clear Lake, Iowa, exploded, and then burned. Two Interstate Power Company employees were injured, one apartment building was destroyed, and the adjacent apartment building was damaged heavily. Damage was estimated a t more than $1 million; none of the residents were injured or killed. - 1/ According to the Plastic Pipe Institute and plastic pipe manufacturers, such as Dupont, Plexco, and Nipak, a butt fusion between two lengths of plastic pipe when properly made, should be as strong or stronger than the plastic pipe itself. A butt weld between two lengths of steel pipe carries the same strength definition, however, here the similarity ends. In the field, accurate, reliable, repeatable, nondestructive testing of steel butt welds can be readily and practically undertaken by X-ray, radioactive isotopes (gamma rays), and magna flux. The American Petroleum Institutes (API) Standards for Welding Pipelines and Related Facilities, API Std 1104, Section 6.0 Standards of Acceptability, and Section 8.0, Radiographic Procedure, set the standards of acceptability for size and type of weld defect, the requirements for producing acceptable radiographs, and the qualifications of the radiographers for the work. Over the years, these API standards have been improved to the point that today field radiographic inspection of butt welds on steel pipes, by qualified, motivated technicians, can be classified as a science. However, the field nondestructive tests for plastic pipe butt fusion cannot be classified as a science. The physical appearance of the fusion is the primary nondestructive field test method. However, the physical appearance test is valid only when all other procedures of squaring the pipe, heating the tool, applying the pressure, and holding the pipe have been rigidly adhered to. During the annual fusion qualification tests given by Interstate to its pipefitters/operators wherein the employees' work was given a physical inspection followed by a destructive test, most of the persons passed both. However, one person's - 1/ For more detailed information, read Pipeline Accident Report-"Interstate Power Company, Natural Gas Explosion and Fire, Clear Lake, Iowa, July 12, 1983" (NTSB-PAR-84/02). 3762-A#

Page 2-2- work passed the visual inspection, but failed the destruclive test; one person's work failed both the visual inspection and the destructive test; and one person failed the visual inspection and passed the destructive test. Interstate stated that all persons had both aspects (visual inspection and destructive testing) before being allowed plastic pipe in actual field operation. Tbe Safety Board is concerned th appearance of a butt fusion joint is more of an art than a science and th to one supervisor may not look good to another and, indeed, upon destructive test fail. As to the July 12, 1983 accident, the report prepared by the testi stated that the external appearance of the failed butt fusion joint w fusion weld wherein uniform fusion of the plastic pipe surfaces had n around the pipe. The findings in this accident raise the question ab plastic butt fusion joints which may have been installed and have a appearance, but which in fact, may be substandard. US. Department of Transportation data for the past year includes on1 that has been attributed to joint failure in plastic pipe; however, the reporting form for pipeline accidents does not have a specific category for joint failure. Acci joint failure in plastic pipe are reported under the "other" category, and joint failure m or may not be specified. Therefore, it is unlikely that the statistics accurately represe the true number of plastic pipe joint failures. The Safety Board estimates that about 3 hours elapsed between the time the 1 was first telephonically reported a t 8 a.m. and rhe explosion a t 11:15 a.m. representative of Interstate stated that the first call was recorded in t 8:48 p.m; however, the clerk who received the call said that she did not the actual time of the initial notification and that she conducted other bu informing the serviceman of the call, before entering the call into thP 8-i) later. As a result of its investigation of a pipeline aecident in Annandale, Vir March 24, 1972, in which three persons died, one person was injured, two hou destroyed, and a third house was badly damaged, z/ the Safety Board r the Office of Pipeline Safety (now the Research and Special Programs the U.S. Department of Transportation: Amend 49 CFR 192 to require that each operator maintain a log shows the receipt and handling of each leak or emergency received. Information concerning the time that the report was first received, that a crew was first dispatched to the scene, - that such a crew arrived, and that the condition was considered safe should be included. In addition, each pipeline operator should be required to analyze h performance in responding to gas leak emergencies and reports. Bot the logs and the analysis should be made available to State agencies the Office of Pipeline Safety. (Safety Recornmendation P-72- (emphasis added) It is important for gas companies to encourage reporting and effective line of communication with the public since the public is the best source f reporting most gas odors/gas leaks. An effective leak response system must include the - 2/ Pipeline Accident Report--"Washington Gas Light Company Natural Annandale, Virginia, March 24, 1972." (NTSB-PAR-72-4)#

Page 3-3- immediate logging of telephone calls about gas odors, the logging of the precise information given (date, time, location, and leak description), and the rapid dissemination of this information to the responding crew. Emergency-type telephone calls should have the highest priority and should be handled completely before attention is given to regular business matters. By so doing, the gas company not only can insure the rapid response to a complaint, but it can check on its own efficiency as to when the crew was dispatched, when the crew arrived, what conditions the crew encountered, and when the condition was rendered safe. Many gas companies tape record all incoming emergency-type telephone calls as a matter of record and as a means to assess their dispatching efficiency. Unfortunately, in this accident, there was no record of the first or second telephone calls from the apartment resident who reported the gas odor, no work order was printed giving the particulars of the leak in time for the serviceman to take with him when he responded, and there was no accurate record of the time the serviceman arrived a t the leak site. Undisciplined handling of gas odor or gas leak telephone calls, as was apparent in this accident, decreases the speed and effectiveness in the response to those calls. Interstate's leak classification system is adequately described in its Inspection, Operations, and Maintenance Plan but was not disseminated to the personnel who respond to the leak odor complaints. In this case, the gas serviceman who first arrived on the scene stated that he did not know anything about a Grade I leak. To his credit, he realized that he had a situation too large and too complex to handle alone and he requested additional help. However, after he had requested help, he did not follow Interstate's Grade I "action criteria" which states he should have evacuated the premises, eliminated sources of ignition, or vented the area. If he had been trained to take these actions and had performed them after he requested additional help, this accident might have been prevented. It is important that all persons who are required to respond to gas odor/gas leak complaints, not just supervisors, be trained and knowledgeable in leak classification and the proper emergency actions. Since October 14, 1970, the Safety Board has issued 88 pipeline safety recommendations to the pipeline industry and to the Research and Special Programs Administration of the TJ. S. Department of Transportation regarding the development of written emergency procedures to be implemented during pipeline emergencies. These recommendations have addressed a range of suggestions from the receipt and rapid processing of telephone calls reporting gas leaks, guidelines for the first person responding to the accident site, the ventilation of gas-filled buildings, the evacuation of residents from buildings, to the rapid shutdown of the failed facility. The Safety Board's concern is twofold: first, a gas company must have complete, written, emergency plans; and second, gas company employees who may be called upon to respond to emergencies must be familiar with these emergency plans to implement them consistently, promptly, and effectively. Interstate's Emergency Plan addresses the logistics of handling emergencies, contacting emergency crews, shutting off gas to entire sections of the community, plans to relight those sections, feeding and housing crews, and names and telephone numbers of company personnel to be contacted by civil agencies. The Emergency Plan, however, does not address the rapid shutdown of failed facilities, warning area residents about a leak, ventilating buildings which contain escaped gas, eliminating ignition sources, or evacuating residents from buildings. Although Section 3.3 of Interstate's Inspection, Operations, and Maintenance Plan addresses the protection of life and property, steps to evacuate persons, rapid shutdown and liaison with the police and fire departments, these activities are keyed to action to be taken after a pipeline is damaged and when emergency maintenance must be undertaken.#

Page 4Neither the Emergency Plan nor the Inspection, Operation ana Maintenance addresses the proper action to take when a leak develops from other causes. In add and more importantly, these plans are for the supervisors use and are not disseminate subordinate employees. In the July 12, 1983 accident, the servicem onscene before the explosion and fire occurred. However, they b aware of the existence of either the Emergency or the Insp Maintenance Plans. In order to have been effective, all persons involved should have been familiar with both plans. Of equal importance with written Emergency Plans and Inspection, Op Maintenance Plans is the training of company personnel and others to rapidly implement these plans in the event of an emergency. In addition to the 88 pipeline safety recommendations for written emergency procedures, the Safety Board, has issued 77 pipeline safety recornmendations since 1969 concerning training of pipeline company personnel and others. Board experience shows that company personnel well versed in their emergency and operations and maintenance plans can reasonably be ex better during periods of emergencies than those who are not. The serviceman sen1 to investigate the gas odor complaint at the acei responded promptly once he was notified, checked the area outside, gas leak as being too big for him to handle, and correctly requested ad a timely fashion. However, having fulfilled the first task, site examin analysis, the serviceman failed to follow through. Although he entered the building with the apartment resident, he did not carry his gas detector (CGI) into hence, he could not accurately determine the amount of gas presen industry-wide practice to equip servicemen with CGIs; however, it i.: a that when servicemen are equipped with CGIs to use them to iheci, the concentration gas in a building. Interstate's action criteria for Grade I leaks gives examples of when B leak should be considered a Grade I. Two examples mention the concentration of gas inside a building. Without the use of some type of detector, there is no way to accurately determine the concentration of gas. When the serviceman entered the building and determined that, to some degree, gas was entering the building, he failed to warn the residents, to ventilate the building, to eliminate sources of ignition (such as shutting off the electricity), and to evacuate the building. Had the serviceman ventilated the building or turned off the electricity to the building, or both, ignition might not have occurred before the gas crew shut off the gas. After the accident, the serviceman stated that he had not been trained to do these things although, on a general basis. hazards of natural gas through his years of practicnl experience. Similarly, when the gas crew arrived and found heavy gas odors failed to warn the residents, to ventilate the buildings (or even to gas buildup), and to evacuate the residents. Later, when the gas c arrived at the site, smelled the gas, and was briefed about the leak a locate the leak, he too failed to act to eliminate sources of ignition or to evacuate th residents. Between 8:30 a.m., when the serviceman arrived at the apartment complex an 11:15 a.m., when the explosion and fire occurred, several measures c to have eliminated the potential danger at the accident site; however, none wer Therefore, the Safety Board believes that adequate emergency and inspection, operation and maintenance plans combined with training subordinate compan areas could have prevented this accident.#

Page 5-5- Therefore, as a result of its investigation, the National Transportation Safety Board recommends that the Interstate Power Company: Review with its pipefitters/operators all elements of its procedures for fusion of plastic pipe emphasizing the importance of strict adherence to each element of these procedures to assure proper fusion. (Class 11, Priority Action) (P-84-11) Review with its gas district clerks procedures for the immediate recording of leak complaints and immediate dispatch of personnel, and stress the importance of immediately recording complaints and ensuring response activity. (Class II, Priority Action) (P-84-12) The National Transportation Safety Board is an independent Federal agency with the statutory responsibility 'I. . .to promote transportation safety by conducting independent accident investigations and by formulating safety improvement recommendations'' (P.L. 93-633). The Safety Board is vitally interested in any actions taken as a result of its safety recommendations and would appreciate a response from you regarding action taken or contemplated with respect to the recommendations in this letter. BURNETT, Chairman, GOLDMAN, Vice Chairman, and BURSLEY and GROSE, Members, concurred in these recommendations.#