NTSB Safety Recommendation Letter P-72-034 through P-72-039

Page 1Official PDFaccumulation of natural gas which had leaked from a broken service-line connection with a 6-inch gas main and. had migrated up and under the concrete slabs of both houses. The length of time taken by gas company personnel to find the leak and their failure to close the three valves of the gas main to iso- late the affected area contributed to the second explosion and fire. The delay in the decision to evacuate the houses until after the second explosion and fire was caused by lack of liaison and coopera- tion between the gas company and the fire department. . VI. R.E.C.OMMENDATIQNS The National Transportation Safety Board recommends that: 1. The Office of Pipeline Safety (a) Amend 49 CFR 192 to include a section based on a review of the ' suitability of threaded galvanized O'' pipe, or pipe coated with other dis- ,7 similar metals, for the transporta- t i o n of natural and other gas. (Recommendation No I P-7 2-34) (b) Amend 49 CFR 192.615 to include an explicit requirement that pipe- / line operators notify and coordinate -, ('7 their activities with local fire and 3 police officials when gas leaks create hazardous conditions. (Recom- mendation No. P-72-.35) 2. The American Society of Mechanical Engineers G a s Piping Standards Committee: Conduct, in conjunction with the I..\ i American Gas Association, a study of the stress effects of various types of soils and backfill on service line- gas main connections As a result of this study, guidelines should be issued for installing underground gas-piping systems. (Recommenda- tion No. P-72-36) 3. The Lone Star Gas Company: 1 n t 7 ' (a) Undertake a program acceptable to the Railroad Commission of the State of Texas, to inspect, on a random-sample basis, the service line - gas main connections similar t o those at the accident site, to de- termine their current condition and the existing stress on the piping The results of this program will de- termine the action to be taken on other installations in the Lone Star system. Copies of these test results should be forwarded to the Railroad Commission of the State of Texas and the Office of Pipeline Safety of the Department of Transportation. (Recommendation No. P-72-37) "'6 (b) Establish a line of communications and hold periodic meetings with local fire departments and other interested agencies to inform them 7 of gas company emergency proced- i ures and maintenance operations. (Recommendation No. P-72-38) (c) Notify and coordinate its activities wit6 local fire and police officials when gas leaks create hazardous conditions. (Recommendation No. P-72-39) 16#