# NTSB Safety Recommendation P-73-005 **Citation:** P-73-005 **Type / status:** guidance / guidance **Agency:** National Transportation Safety Board **Effective:** 1973-05-16 **Published:** 1973-05-16 THE NTSB RECOMMENDS THAT: THE DEPARTMENT OF LABOR REVIEW ITS OCCUPATIONAL SAFETY AND HEALTH REGULATION 29 CFR 1926.651(A) TO REQUIRE THAT A POSITIVE DETERMINATION BE MADE AS TO THE LOCATION OF UNDERGROUND FACILITIES AT THE PROPOSED EXCAVATION SITE. ## Document text NTSB safety recommendation P-73-005. THE NTSB RECOMMENDS THAT: THE DEPARTMENT OF LABOR REVIEW ITS OCCUPATIONAL SAFETY AND HEALTH REGULATION 29 CFR 1926.651(A) TO REQUIRE THAT A POSITIVE DETERMINATION BE MADE AS TO THE LOCATION OF UNDERGROUND FACILITIES AT THE PROPOSED EXCAVATION SITE. Priority: CLASS II Overall Status: Closed - Acceptable Alternate Action Issued Date: 1973-05-16 Adopted Date: 1973-05-16 Overall Date Closed: 1983-03-28 Synopsis: On October 30, 1972, a bulldozer struck and snapped a 3/4-inch gas-service line in Lake City, Minn. A department store located near the rupture, but not served by gas, blew up and later caught fire. Six persons died as a result of the explosion and 10 more were injured. The Northern States Power Company (NSP) later unearthed the entire service line and discovered that in addition to being snapped by the bulldozer, the line had been pulled out of a compression coupling next to the main. Gas had permeated the soil, migrated into the department-store basement, accumulated, and exploded. Ntsbnumber: PLD73XR001 Report Number: PAR-73-01 Addressee Name: United States Department of Labor Addressee Status: Closed--No Longer Applicable Addressee Date Closed: 1983-03-28 Addressee Acronym: DOL Addressee Organization Type: G-Federal Government Communication Date: 1973-07-20 Communication Type: Non-Recipient Correspondence Communication Contents: THIS LETTER IS FROM THE DEPARTMENT OF TRANSPORTATION, NOT THE RECIPIENT OF THE RECOMMENDATION. THIS IS NON-RECIPIENT CORRESPONDENCE: -From Benjamin O. Davis, Jr., Assistant Secretary for Environment, Safety, and Consumer Affairs, Office of Pipeline Safety, United States Department of Transportation: We have reviewed your Pipeline Accident Report No. PAR-7 3·-1 on the October 30, 1972, incident at Lake City, Minnesota, and the recommendations included therein. With regard to the recommendations made to the Office of Pipeline Safety (OPS), we wish to advise that on April 30, 1973, a contract was awarded to the Mechanics Research Institute to conduct a study on the rapid shutdown of failed pipeline facilities and pressure limiting of pipeline systems. Included in the contract work will be a study of fail-safe devices as recommended in the National Transportation Safety Board (NTSB) recommendation No. P-73-2. This study will also relate to the number and location of emergency valves in high pressure distribution systems as recommended in recommendation No. P-73-4. This contract study is scheduled for completion in December 1973. The OPS will then evaluate the data obtained and take the appropriate action. We will keep you advised of the action taken in this regard. In addition, NTSB recommendation No. P-73-4 requests consideration for placing valve keys in the hands of local authorities. This portion of the recommendation is being considered in connection with the OPS's plan to clarify the intent of the requirements for operating and maintenance plans and emergency plans as outlined in our letter to you dated July 5, 1973. We agree with NTSB recommendation No. P-73-3 insofar as it recommends a review of the regulations relative to the uncertainty as to the conditions which permit the use of compression couplings. Such a review will shortly be initiated. To the extent that the review shows a need for amending Paragraph 192.367(b), rulemaking will be initiated. The OPS also concurs with the recommendations made by NTSB to the other parties of interest in this Lake City incident. The NTSB's recommendations No. P-73-5 to the Department of Labor and No. P-73-11 to the Department of Public Works of Lake City, Minnesota, will lend support to the OPS program to promote the Model Statute For The Protection of Underground Pipelines and Utilities. The NTSB recommendation No. P-73-·6 to the American Society of Mechanical Engineers Gas Piping Standards Committee (ASME) will support the OPS recommendation to that Society to develop guideline material on the location of emergency valves. The OPS has suggested to ASME that they include such guideline material in a supplement to the "ASME Guide For Gas Transmission and Distribution Pipeline Systems -1973." The recommendations Nos. P-73-7 through 10 to the Northern States Power Company all relate to areas that we are emphasizing in the OPS/State agencies pipeline safety seminars that are presently being conducted throughout the country. These areas will also be included in our considerations for clarifying the intent of the requirements for operating and maintenance plans and emergency plans as discussed in our letter of July 5. We greatly appreciate your pipeline accident investigation report and will continue to take the appropriate actions as indicated. Addressee Acronym: DOL Addressee Organization Type: G-Federal Government Communication Date: 1982-11-18 Communication Type: Official Correspondence Communication Contents: DEPARTMENT OF LABOR LETTER: THE OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION (OSHA) HAS BEEN WORKING IN SEVERAL AREAS TO DEVELOP THE NECESSARY SUPPORTING DATA TO PROPOSE STANDARDS TO ADDRESS THE NTSB RECOMMENDATIONS. INITIALLY, OSHA ENTERED INTO A CONTRACT WITH THE NATIONAL BUREAU OF STANDARDS TO RESEARCH THE HAZARDS AND THE CONTROL MEASURES NEEDED FOR TRENCHING AND EXCAVATION OPERATIONS. THIS CONTRACT HAS BEEN COMPLETED AND ALL REPORTS HAVE BEEN REVIEWED BY OSHA. I HAVE DIRECTED OUR SAFETY STANDARDS DIRECTORATE TO DEVELOP A COMPREHENSIVE PROPOSAL TO REVISE COMPLETELY THE OSHA CONSTRUCTION STANDARDS ADDRESSING TRENCHING AND EXCAVATION OPERATIONS. THIS PROPOSAL WILL BE PUBLISHED NEXT YEAR, AND IT WILL ADDRESS CLEARLY THE NEED TO DETERMINE CORRECTLY THE LOCATION OF UNDERGROUND UTILITIES, AND ALSO TO CONTACT THE LOCAL PUBLIC UTILITY TO OBTAIN ACCURATE INFORMATION ON THE SAME. Addressee Acronym: DOL Addressee Organization Type: G-Federal Government Communication Date: 1983-03-28 Communication Type: Official Correspondence Addressee Acronym: DOL Addressee Organization Type: G-Federal Government Communication Date: 1982-10-08 Communication Type: Official Correspondence ## Provenance - Official: Yes - Source: - Source ID: `ntsb-pipeline` - SHA-256: `fd60bf77637550680c6125e9f31bb4741703c84b3e7c791ef40a8d069af11ba9` - Retrieved: 2026-08-20T04:57:24.741Z - Exported: 2026-08-22T20:34:52.717Z - Document slug: `ntsb-recommendation-p-73-005` ### Source metadata ```json { "recordKind": "ntsb_safety_recommendation", "safetyRecommendationNumber": "P-73-005", "recommendationMode": "Pipeline", "topicMode": "Pipeline", "ntsbNumber": "PLD73XR001", "priority": "CLASS II", "overallStatus": "Closed - Acceptable Alternate Action", "overallStatusAcronym": "CAAA", "overallDateClosed": "1983-03-28", "lastModifiedDate": "2016-11-15", "reportNumber": "PAR-73-01", "reportUrl": "https://www.ntsb.gov/investigations/Pages/PLD73XR001.aspx", "transmittalLetterUrl": "http://www.ntsb.gov/safety/safety-recs/recletters/P73_2_11.pdf", "addressees": [ { "addresseeName": "United States Department of Labor", "addresseeStatusAcronym": "CNLA", "addresseeStatus": "Closed--No Longer Applicable", "addresseeDateClosed": "1983-03-28", "addresseeDetails": [ { "addresseeAcronym": "DOL", "addresseeOrganizationType": "G-Federal Government", "isFromNtsb": false, "communicationDate": "1973-07-20", "communicationType": "Non-Recipient Correspondence", "communicationContents": "THIS LETTER IS FROM THE DEPARTMENT OF TRANSPORTATION, NOT THE RECIPIENT OF THE RECOMMENDATION. THIS IS NON-RECIPIENT CORRESPONDENCE: -From Benjamin O. Davis, Jr., Assistant Secretary for Environment, Safety, and Consumer Affairs, Office of Pipeline Safety, United States Department of Transportation: We have reviewed your Pipeline Accident Report No. PAR-7 3·-1 on the October 30, 1972, incident at Lake City, Minnesota, and the recommendations included therein.\r\n\r\nWith regard to the recommendations made to the Office of Pipeline Safety (OPS), we wish to advise that on April 30, 1973, a contract was awarded to the Mechanics Research Institute to conduct a study on the rapid shutdown of failed pipeline facilities and pressure limiting of pipeline systems. Included in the contract work will be a study of fail-safe devices as recommended in the National Transportation Safety Board (NTSB) recommendation No. P-73-2. This study will also relate to the number and location of emergency valves in high pressure distribution systems as recommended in recommendation No. P-73-4. This contract study is scheduled for completion in December 1973. The OPS will then evaluate the data obtained and take the appropriate action. We will keep you advised of the action taken in this regard.\r\n\r\nIn addition, NTSB recommendation No. P-73-4 requests consideration for placing valve keys in the hands of local authorities. This portion of the recommendation is being considered in connection with the OPS's plan to clarify the intent of the requirements for operating and maintenance plans and emergency plans as outlined in our letter to you dated July 5, 1973.\r\n\r\nWe agree with NTSB recommendation No. P-73-3 insofar as it recommends a review of the regulations relative to the uncertainty as to the conditions which permit the use of compression couplings. Such a review will shortly be initiated. To the extent that the review shows a need for amending Paragraph 192.367(b), rulemaking will be initiated.\r\n\r\nThe OPS also concurs with the recommendations made by NTSB to the other parties of interest in this Lake City incident. The NTSB's recommendations No. P-73-5 to the Department of Labor and No. P-73-11 to the Department of Public Works of Lake City, Minnesota, will lend support to the OPS program to promote the Model Statute For The Protection of Underground Pipelines and Utilities. The NTSB recommendation No. P-73-·6 to the American Society of Mechanical Engineers Gas Piping Standards Committee (ASME) will support the OPS recommendation to that Society to develop guideline material on the location of emergency valves. The OPS has suggested to ASME that they include such guideline material in a supplement to the \"ASME Guide For Gas Transmission and Distribution Pipeline Systems -1973.\" The recommendations Nos. P-73-7 through 10 to the Northern States Power Company all relate to areas that we are emphasizing in the OPS/State agencies pipeline safety seminars that are presently being conducted throughout the country. These areas will also be included in our considerations for clarifying the intent of the requirements for operating and maintenance plans and emergency plans as discussed in our letter of July 5.\r\n\r\nWe greatly appreciate your pipeline accident investigation report and will continue to take the appropriate actions as indicated." }, { "addresseeAcronym": "DOL", "addresseeOrganizationType": "G-Federal Government", "isFromNtsb": false, "communicationDate": "1982-11-18", "communicationType": "Official Correspondence", "communicationContents": "DEPARTMENT OF LABOR LETTER: THE OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION (OSHA) HAS BEEN WORKING IN SEVERAL AREAS TO DEVELOP THE NECESSARY SUPPORTING DATA TO PROPOSE STANDARDS TO ADDRESS THE NTSB RECOMMENDATIONS. INITIALLY, OSHA ENTERED INTO A CONTRACT WITH THE NATIONAL BUREAU OF STANDARDS TO RESEARCH THE HAZARDS AND THE CONTROL MEASURES NEEDED FOR TRENCHING AND EXCAVATION OPERATIONS. THIS CONTRACT HAS BEEN COMPLETED AND ALL REPORTS HAVE BEEN REVIEWED BY OSHA. I HAVE DIRECTED OUR SAFETY STANDARDS DIRECTORATE TO DEVELOP A COMPREHENSIVE PROPOSAL TO REVISE COMPLETELY THE OSHA CONSTRUCTION STANDARDS ADDRESSING TRENCHING AND EXCAVATION OPERATIONS. THIS PROPOSAL WILL BE PUBLISHED NEXT YEAR, AND IT WILL ADDRESS CLEARLY THE NEED TO DETERMINE CORRECTLY THE LOCATION OF UNDERGROUND UTILITIES, AND ALSO TO CONTACT THE LOCAL PUBLIC UTILITY TO OBTAIN ACCURATE INFORMATION ON THE SAME." }, { "addresseeAcronym": "DOL", "addresseeOrganizationType": "G-Federal Government", "isFromNtsb": true, "communicationDate": "1983-03-28", "communicationType": "Official Correspondence", "communicationContents": "" }, { "addresseeAcronym": "DOL", "addresseeOrganizationType": "G-Federal Government", "isFromNtsb": true, "communicationDate": "1982-10-08", "communicationType": "Official Correspondence", "communicationContents": "" } ] } ], "jurisdiction": "US" } ```