COLUMBIA GULF TRANSMISSION LLC � CARTER CREEK FACILITIES — Warning Letter

12024008WL_Warning Letter_01182024_(23-264052)_text.pdf, page 1Official PDFWARNING LETTER OVERNIGHT EXPRESS DELIVERY January 18, 2024 Ms. Tina Faraca Executive Vice-President & President, U.S. Natural Gas Pipelines North Baja Pipeline, LLC., a subsidiary of TC Energy Corporation 700 Louisiana Street Houston, Texas 77002 CPF 1-2024-008-WL Dear Ms. Faraca: From August 8 to 10, 2023, at an onsite inspection in Omaha, Nebraska, representatives of the Pipeline and Hazardous Materials Safety Administration (PHMSA) pursuant to Chapter 601 of 49 United States Code (U.S.C.) inspected the operator qualification records applicable to multiple TC Energy units, which included Columbia Gulf Transmission LLC – Carter Creek Facilities (CGTCC) in Uinta County, Wyoming. As a result of the inspection, it is alleged that you have committed a probable violation of the Pipeline Safety Regulations, Title 49, Code of Federal Regulations (CFR). The item inspected and the probable violation is: 1. § 192.745 Valve maintenance: Transmission lines. (a) Each transmission line valve that might be required during any emergency must be inspected and partially operated at intervals not exceeding 15 months, but at least once each calendar year. CGTCC failed to inspect and partially operate transmission line valves that might be required during an emergency at intervals not to exceed 15 months, but at least once each calendar year as required by § 192.745(a). During the inspection, PHMSA requested the records related to designated emergency transmission valves falling under § 192.745(a) inspection requirements for the Carter Creek Facilities located in Uinta County, Wyoming. CGTCC could not provide any 2022 valve inspection reports and stated that records were not available due to contractor staff turn-over. CGTCC provided pre-inspection OQ records; however, there was no evidence to indicate that the § 192.745(a) inspections were performed#

12024008WL_Warning Letter_01182024_(23-264052)_text.pdf, page 2in 2022. Additionally, 2021 records provided for the Carter Creek valve inspections indicated that 9 out of 11 emergency valves had not been partially operated as required by § 192.745(a). Therefore, CGTCC failed to inspect and partially operate transmission line valves that might be required in an emergency for its Carter Creek facilities in accordance with § 192.745(a) during the years 2021 and 2022. Under 49 U.S.C. § 60122 and 49 CFR § 190.223, you are subject to a civil penalty not to exceed $257,664 per violation per day the violation persists, up to a maximum of $2,576,627 for a related series of violations. For violation occurring on or after March 21, 2022 and before January 6, 2023, the maximum penalty may not exceed $239,142 per violation per day the violation persists, up to a maximum of $2,391,142 for a related series of violations. For violation occurring on or after May 3, 2021 and before March 21, 2022, the maximum penalty may not exceed $225,134 per violation per day the violation persists, up to a maximum of $2,251,334 for a related series of violations. For violation occurring on or after January 11, 2021 and before May 3, 2021, the maximum penalty may not exceed $222,504 per violation per day the violation persists, up to a maximum of $2,225,034 for a related series of violations. For violation occurring on or after July 31, 2019 and before January 11, 2021, the maximum penalty may not exceed $218,647 per violation per day the violation persists, up to a maximum of $2,186,465 for a related series of violations. For violation occurring on or after November 27, 2018 and before July 31, 2019, the maximum penalty may not exceed $213,268 per violation per day, with a maximum penalty not to exceed $2,132,679. For violation occurring on or after November 2, 2015 and before November 27, 2018, the maximum penalty may not exceed $209,002 per violation per day, with a maximum penalty not to exceed $2,090,022. We have reviewed the circumstances and supporting documents involved in this case, and have decided not to conduct additional enforcement action or penalty assessment proceedings at this time. We advise you to correct the item identified in this letter. Failure to do so will result in Columbia Gulf Transmission LLC – Carter Creek Facilities being subject to additional enforcement action. No reply to this letter is required. If you choose to reply, in your correspondence please refer to CPF 1-2024-008-WL. Be advised that all material you submit in response to this enforcement action is subject to being made publicly available. If you believe that any portion of your responsive material qualifies for confidential treatment under 5 U.S.C. § 552(b), along with the complete original document you must provide a second copy of the document with the portions you believe qualify for confidential treatment redacted and an explanation of why you believe the redacted information qualifies for confidential treatment under 5 U.S.C. § 552(b). Sincerely, Robert Burrough Director, Eastern Region, Office of Pipeline Safety Pipeline and Hazardous Materials Safety Administration Cc: Daniel Cerkoney <dan_cerkoney@tcenergy.com> Amy Willis <amy_willis@tcenergy.com>#