# NTSB Safety Recommendation P-93-019 **Citation:** P-93-019 **Type / status:** guidance / guidance **Agency:** National Transportation Safety Board **Effective:** 1993-12-15 **Published:** 1993-12-15 THE NTSB RECOMMENDATIONS THAT THE AMERICAN PETROLEUM INSTITUTE: DEVELOP RECOMMENDED SAFETY PRACTICE FOR THE DESIGN, CONSTRUCTION, AND OPERATION OF HIGHLY VOLATILE LIQUID AND NATURAL GAS GEOLOGIC UNDERGROUND STORAGE FACILITIES OTHER THAN SOLUTION-MINED STORAGE FACILITIES. ## Document text NTSB safety recommendation P-93-019. THE NTSB RECOMMENDATIONS THAT THE AMERICAN PETROLEUM INSTITUTE: DEVELOP RECOMMENDED SAFETY PRACTICE FOR THE DESIGN, CONSTRUCTION, AND OPERATION OF HIGHLY VOLATILE LIQUID AND NATURAL GAS GEOLOGIC UNDERGROUND STORAGE FACILITIES OTHER THAN SOLUTION-MINED STORAGE FACILITIES. Priority: CLASS II Overall Status: Closed - Reconsidered Issued Date: 1993-12-15 Adopted Date: 1993-11-04 Overall Date Closed: 1997-03-20 Synopsis: ON APRIL 7, 1992, AN UNCONTROLLED RELEASE OF HIGHLY VOLATILE LIQUIDS (HVLS) FROM A SALT DOME STORAGE CAVERN IN THE SEMINOLE PIPELINE SYSTEM NEAR BRENHAM, TEXAS, FORMED A LARGE, HEAVIER-THAN-AIR GAS CLOUD THAT EXPLODED. THREE PEOPLE DIED FROM INJURIES SUSTAINED EITHER FROM THE BLAST OR IN THE FIRE. AN ADDITIONAL 21 PEOPLE WERE TREATED FOR INJURIES AT AREA HOSPITALS. DAMAGE FROM THE ACCIDENT EXCEEDED $9 MILLION. Probable Cause: None Ntsbnumber: DCA92MP006 Report Number: PAR-93-01 Addressee Name: American Petroleum Institute Addressee Status: Closed - Reconsidered Addressee Date Closed: 1997-03-20 Addressee Acronym: API Addressee Organization Type: A-Associations Communication Date: 1996-08-05 Communication Type: Official Correspondence Communication Contents: API MEMBER COMPANIES DO NOT CURRENTLY OPERATE GEOLOGIC UNDERGROUND STORAGE FACILITIES: SUCH FACILITIES ARE PRIMARILY FOR NATURAL GAS. FOR THIS REASON API DOES NOT HAVE THE REQUISITE TECHNICAL EXPERTISE TO DRAFT A RECOMMENDED PRACTICE. Addressee Acronym: API Addressee Organization Type: A-Associations Communication Date: 1994-01-12 Communication Type: Official Correspondence Communication Contents: SINCE GEOLOGICAL STORAGE IS USED FOR NATURAL GAS, AGA HAS AGREED TO TAKE THE LEAD IN DEVELOPING SUCH A STANDARD IN COORDINATION WITH THE API. Addressee Acronym: API Addressee Organization Type: A-Associations Communication Date: 1994-07-27 Communication Type: Official Correspondence Communication Contents: THE AMERICAN GAS ASSOCIATION HAS AGREED TO TAKE THE LEAD IN RESPONDING TO P-93-19. WE ARE CONTINUING TO COORDINATE OUR EFFORTS WITH THEIRS. Addressee Acronym: API Addressee Organization Type: A-Associations Communication Date: 1994-11-02 Communication Type: Official Correspondence Communication Contents: AGA HAS AGREED TO TAKE THE LEAD IN RESPONDING TO SAFETY RECOMMENDATION P-93-19. Addressee Acronym: API Addressee Organization Type: A-Associations Communication Date: 1997-03-20 Communication Type: Official Correspondence Communication Contents: THE BOARD ISSUED P-93-19 & -20 AS A RESULT OF ITS INVESTIGATION OF THE APRIL 1992 EXPLOSION IN THE SEMINOLE PIPELINE SYSTEM NEAR BRENHAM, TEXAS. P-93-19 ASKED API TO DEVELOP PRECOMMENDED SAFETY PRACTICES FOR THE DESIGN, CONSTRUCTION, & OPERATION OF HIGHLY VOLATILE LIQUID & NATURAL GAS GEOLOGIC UNDERGROUND STORAGE FACILITIES OTHER THAN SOLUTION-MINED STORAGE FACILITIES. THE API HAS ADVISED THE BOARD THAT ITS MEMBERS DO NOT PRESENTLY OPERATE GEOLOGIC UNDERGROUND STORAGE FACILITIES; THEREFORE, P-93-19 HAS BEEN CLASSIFIED "CLOSED--RECONSIDERED." Addressee Acronym: API Addressee Organization Type: A-Associations Communication Date: 1994-02-22 Communication Type: Official Correspondence Communication Contents: THE BOARD UNDERSTANDS THAT THE API HAS DISCUSSED THIS RECOMMENDATION WITH REPRESENTATIVES OF THE AMERICAN GAS ASSOCIATION (AGA) AND THAT THE AGA HAS AGREED TO TAKE THE LEAD IN DEVELOPING SUCH A STANDARD. PENDING FURTHER RESPONSE FROM YOUR OFFICE, RECOMMENDATION P-93-19 WILL BE CLASSIFIED AS "OPEN--ACCEPTABLE ALTERNATE RESPONSE." Addressee Acronym: API Addressee Organization Type: A-Associations Communication Date: 1994-10-17 Communication Type: Official Correspondence Communication Contents: THE BOARD NOTES THAT THE API WILL COORDINATE ITS EFFORTS WITH THE AMERICAN GAS ASSOCIATION (AGA) TO MEET THE INTENT OF THIS RECOMMENDATION. PENDING FURTHER RESPONSE, RECOMMENDATION P-93-19 IS CLASSIFIED "OPEN--ACCPETABLE RSPONSE." Addressee Acronym: API Addressee Organization Type: A-Associations Communication Date: 1995-02-24 Communication Type: Official Correspondence Communication Contents: THE BOARD UNDERSTANDS THAT THE AMERICAN GAS ASSOCIATION (AGA) HAS AGREED TO DEVELOP SAFETY PRACTICES AS NOTED IN THIS RECOMMENDATION. PENDING THEIR DEVELOPMENT, P-93-19 HAS BEEN CLASSIFIED "OPEN--ACCEPTABLE RESPONSE." ## Provenance - Official: Yes - Source: - Source ID: `ntsb-pipeline` - SHA-256: `7adc7d724ae82dcc22e1eba3fc3fae9946b35d60e5ae70cc0b0ac989ae04a707` - Retrieved: 2026-08-20T04:57:24.741Z - Exported: 2026-08-22T01:39:10.059Z - Document slug: `ntsb-recommendation-p-93-019` ### Source metadata ```json { "recordKind": "ntsb_safety_recommendation", "safetyRecommendationNumber": "P-93-019", "recommendationMode": "Pipeline", "topicMode": "Pipeline", "ntsbNumber": "DCA92MP006", "priority": "CLASS II", "overallStatus": "Closed - Reconsidered", "overallStatusAcronym": "CR", "overallDateClosed": "1997-03-20", "lastModifiedDate": "2016-11-15", "reportNumber": "PAR-93-01", "reportUrl": "https://www.ntsb.gov/investigations/Pages/DCA92MP006.aspx", "transmittalLetterUrl": "http://www.ntsb.gov/safety/safety-recs/recletters/P93_18_20.pdf", "addressees": [ { "addresseeName": "American Petroleum Institute", "addresseeStatusAcronym": "CR", "addresseeStatus": "Closed - Reconsidered", "addresseeDateClosed": "1997-03-20", "addresseeDetails": [ { "addresseeAcronym": "API", "addresseeOrganizationType": "A-Associations", "isFromNtsb": false, "communicationDate": "1996-08-05", "communicationType": "Official Correspondence", "communicationContents": "API MEMBER COMPANIES DO NOT CURRENTLY OPERATE GEOLOGIC UNDERGROUND STORAGE FACILITIES: SUCH FACILITIES ARE PRIMARILY FOR NATURAL GAS. FOR THIS REASON API DOES NOT HAVE THE REQUISITE TECHNICAL EXPERTISE TO DRAFT A RECOMMENDED PRACTICE." }, { "addresseeAcronym": "API", "addresseeOrganizationType": "A-Associations", "isFromNtsb": false, "communicationDate": "1994-01-12", "communicationType": "Official Correspondence", "communicationContents": "SINCE GEOLOGICAL STORAGE IS USED FOR NATURAL GAS, AGA HAS AGREED TO TAKE THE LEAD IN DEVELOPING SUCH A STANDARD IN COORDINATION WITH THE API." }, { "addresseeAcronym": "API", "addresseeOrganizationType": "A-Associations", "isFromNtsb": false, "communicationDate": "1994-07-27", "communicationType": "Official Correspondence", "communicationContents": "THE AMERICAN GAS ASSOCIATION HAS AGREED TO TAKE THE LEAD IN RESPONDING TO P-93-19. WE ARE CONTINUING TO COORDINATE OUR EFFORTS WITH THEIRS." }, { "addresseeAcronym": "API", "addresseeOrganizationType": "A-Associations", "isFromNtsb": false, "communicationDate": "1994-11-02", "communicationType": "Official Correspondence", "communicationContents": "AGA HAS AGREED TO TAKE THE LEAD IN RESPONDING TO SAFETY RECOMMENDATION P-93-19." }, { "addresseeAcronym": "API", "addresseeOrganizationType": "A-Associations", "isFromNtsb": true, "communicationDate": "1997-03-20", "communicationType": "Official Correspondence", "communicationContents": "THE BOARD ISSUED P-93-19 & -20 AS A RESULT OF ITS INVESTIGATION OF THE APRIL 1992 EXPLOSION IN THE SEMINOLE PIPELINE SYSTEM NEAR BRENHAM, TEXAS. P-93-19 ASKED API TO DEVELOP PRECOMMENDED SAFETY PRACTICES FOR THE DESIGN, CONSTRUCTION, & OPERATION OF HIGHLY VOLATILE LIQUID & NATURAL GAS GEOLOGIC UNDERGROUND STORAGE FACILITIES OTHER THAN SOLUTION-MINED STORAGE FACILITIES. THE API HAS ADVISED THE BOARD THAT ITS MEMBERS DO NOT PRESENTLY OPERATE GEOLOGIC UNDERGROUND STORAGE FACILITIES; THEREFORE, P-93-19 HAS BEEN CLASSIFIED \"CLOSED--RECONSIDERED.\"" }, { "addresseeAcronym": "API", "addresseeOrganizationType": "A-Associations", "isFromNtsb": true, "communicationDate": "1994-02-22", "communicationType": "Official Correspondence", "communicationContents": "THE BOARD UNDERSTANDS THAT THE API HAS DISCUSSED THIS RECOMMENDATION WITH REPRESENTATIVES OF THE AMERICAN GAS ASSOCIATION (AGA) AND THAT THE AGA HAS AGREED TO TAKE THE LEAD IN DEVELOPING SUCH A STANDARD. PENDING FURTHER RESPONSE FROM YOUR OFFICE, RECOMMENDATION P-93-19 WILL BE CLASSIFIED AS \"OPEN--ACCEPTABLE ALTERNATE RESPONSE.\"" }, { "addresseeAcronym": "API", "addresseeOrganizationType": "A-Associations", "isFromNtsb": true, "communicationDate": "1994-10-17", "communicationType": "Official Correspondence", "communicationContents": "THE BOARD NOTES THAT THE API WILL COORDINATE ITS EFFORTS WITH THE AMERICAN GAS ASSOCIATION (AGA) TO MEET THE INTENT OF THIS RECOMMENDATION. PENDING FURTHER RESPONSE, RECOMMENDATION P-93-19 IS CLASSIFIED \"OPEN--ACCPETABLE RSPONSE.\"" }, { "addresseeAcronym": "API", "addresseeOrganizationType": "A-Associations", "isFromNtsb": true, "communicationDate": "1995-02-24", "communicationType": "Official Correspondence", "communicationContents": "THE BOARD UNDERSTANDS THAT THE AMERICAN GAS ASSOCIATION (AGA) HAS AGREED TO DEVELOP SAFETY PRACTICES AS NOTED IN THIS RECOMMENDATION. PENDING THEIR DEVELOPMENT, P-93-19 HAS BEEN CLASSIFIED \"OPEN--ACCEPTABLE RESPONSE.\"" } ] } ], "jurisdiction": "US" } ```