WESTGAS INTERSTATE, INC — Notice of Probable Violation

party submissionOfficial PDF52025026NOPV_Operator Response to Notice_09192025_(24-297246).pdf#

case documentOfficial PDF52025026NOPV_PCO_07292025_(24-297246).pdf#

case documentOfficial PDF52025026NOPV_PCO_07292025_(24-297246)_text.pdf#

52025026NOPV_Closure Letter_05012026_(24-297246)_text.pdf, page 1Official PDFU.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration 12300 West Dakota Avenue, Suite 340 Lakewood, Colorado 80228 VIA ELECTRONIC MAIL TO: Lauren.Gilliland@xcelenergy.com May 1, 2026 Lauren Gilliland Senior Vice President, Gas WestGas InterState, Inc. 1800 Larimer St. Denver, CO 80202 CPF 5-2025-026-NOPV Closure Letter Dear Ms. Gilliland: On October 14, 2025, the Pipeline and Hazardous Materials Safety Administration (PHMSA) issued to WestGas InterState, Inc. a Final Order. This Order included a Compliance Order. Based on our review of the documentation you provided, it has been determined that you have complied with the terms of this Order. Accordingly, this case is now closed, and no further action is contemplated with respect to the matters involved in this case. Thank you for your cooperation in this matter. Sincerely, Dustin Hubbard Director, Western Region, Office of Pipeline Safety Pipeline and Hazardous Materials Safety Administration cc: PHP-60 Compliance Registry PHP-500 L. Salvador (24-297246) Nathan Gonzales, Principal Engineer, nathan.a.gonzales@xcelenergy.com#

52025026NOPV_Final Order_10142025_(24-297246)_text.pdf, page 1Official PDFOctober 14, 2025 VIA ELECTRONIC MAIL TO: Lauren.Gilliland@xcelenergy.com Lauren Gilliland Vice President, Gas WestGas InterState, Inc. 1800 Larimer St. Denver, CO 80202 Re: CPF No. 5-2025-026-NOPV Dear Ms. Gilliland: Enclosed please find the Final Order issued in the above-referenced case. It makes a finding of violation and specifies actions that need to be taken to comply with the pipeline safety regulations. When the terms of the compliance order are completed, as determined by the Director, Western Region, this enforcement action will be closed. Service of the Final Order by e-mail is effective upon the date of transmission and acknowledgement of receipt as provided under 49 CFR § 190.5. Thank you for your cooperation in this matter. Sincerely, Linda Daugherty Acting Associate Administrator for Pipeline Safety Enclosures (Final Order and NOPV) cc: Dustin Hubbard, Director, Western Region, Office of Pipeline Safety Nathan Gonzales, Principal Engineer, Gas Standards, Xcel Energy, Nathan.A.Gonzales@xcelenergy.com CONFIRMATION OF RECEIPT REQUESTED#

52025026NOPV_Final Order_10142025_(24-297246)_text.pdf, page 2U.S. DEPARTMENT OF TRANSPORTATION PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION OFFICE OF PIPELINE SAFETY WASHINGTON, D.C. 20590 ____________________________________ ) In the Matter of ) ) WestGas InterState, Inc., ) a subsidiary of Xcel Energy ) CPF No. 5-2025-026-NOPV ) Respondent. ) ____________________________________) FINAL ORDER On July 29, 2025, pursuant to 49 CFR § 190.207, the Director, Western Region, Office of Pipeline Safety (OPS), issued a Notice of Probable Violation (Notice) to WestGas InterState, Inc. (Respondent). The Notice proposed finding that Respondent had violated the pipeline safety regulations in 49 CFR Part 192. The Notice also proposed certain measures to correct the violations. Respondent did not contest the allegations of violation or corrective measures. Based upon a review of all of the evidence, pursuant to § 190.213, I find Respondent violated the pipeline safety regulations listed below, as more fully described in the enclosed Notice, which is incorporated by reference: 49 CFR § 192.739(a) (Item 1) ─ Respondent failed to inspect and test its pressure limiting devices to determine if they were in good mechanical condition, adequate from the standpoint of capacity and reliability of operation for the service in which it is employed, and properly installed and protected. This finding of violation will be considered a prior offense in any subsequent enforcement action taken against Respondent. Compliance Actions Pursuant to 49 U.S.C. § 60118(b) and 49 CFR § 190.217, Respondent is ordered to take the actions proposed in the enclosed Notice to correct the violation. The Director may grant an extension of time to comply with any of the required items upon a written request timely submitted by the Respondent and demonstrating good cause for an extension. Upon completion of the ordered actions, Respondent may request that the Director close the case. Failure to comply with this Order may result in the assessment of civil penalties under 49 CFR § 190.223#

52025026NOPV_Final Order_10142025_(24-297246)_text.pdf, page 3or in referral to the Attorney General for appropriate relief in a district court of the United States. The terms and conditions of this order are effective upon service in accordance with 49 CFR § 190.5. ___________________________________ _________________________ Linda Daugherty Date Issued Acting Associate Administrator for Pipeline Safety#

52025026NOPV_Final Order_10142025_(24-297246)_text.pdf, page 4NOTICE OF PROBABLE VIOLATION and PROPOSED COMPLIANCE ORDER VIA ELECTRONIC MAIL TO: Lauren.Gilliland@xcelenergy.com July 29, 2025 Ms. Lauren Gilliland VP Gas Operations Westgas Interstate, Inc. 1800 Larimer St. Denver, CO 80202 CPF 5-2025-026-NOPV Dear Ms. Gilliland: From October 28, 2024 to October 31, 2024, representatives of the Pipeline and Hazardous Materials Safety Administration (PHMSA), Office of Pipeline Safety (OPS), pursuant to Chapter 601 of 49 United States Code (U.S.C.) inspected Westgas Interstate, Inc.’s (Westgas) natural gas system in northern Colorado and southern Wyoming. As a result of the inspection, it is alleged that Westgas has committed probable violations of the Pipeline Safety Regulations, Title 49, Code of Federal Regulations (CFR). The items inspected and the probable violations are: 1. § 192.739 Pressure limiting and regulating stations: Inspection and testing. (a) Each pressure limiting station, relief device (except rupture discs), and pressure regulating station and its equipment must be subjected at intervals not exceeding 15 months, but at least once each calendar year, to inspections and tests to determine that it is-- (1) In good mechanical condition;#

52025026NOPV_Final Order_10142025_(24-297246)_text.pdf, page 5(2) Adequate from the standpoint of capacity and reliability of operation for the service in which it is employed; (3) Except as provided in paragraph (b) of this section, set to control or relieve at the correct pressure consistent with the pressure limits of § 192.201(a); and (4) Properly installed and protected from dirt, liquids, or other conditions that might prevent proper operation. Westgas failed to inspect and test its pressure limiting devices at least once a calendar year, at intervals not to exceed 15 months, to determine if they are in good mechanical condition, adequate from the standpoint of capacity and reliability of operation for the service in which they are employed, set to control or relieve at the correct pressure consistent with the pressure limits of § 192.201(a), and properly installed and protected from dirt, liquids, or other conditions that might prevent proper operation as required. Specifically, during inspection, Westgas could not establish through documentation that it had inspected the pressure limiting slam-shut valves at the Chalk Bluff station for the calendar years of 2020, 2021, 2022, 2023 and 2024. Section 192.739(a) requires operators to inspect each pressure limiting station, relief device, and pressure regulating station and its equipment each calendar year at intervals not exceeding 15 months. However, during the inspection Westgas could not provide to the PHMSA inspectors any records such as inspection reports, test results, or other documentation to demonstrate that the required inspections and tests had been conducted during the calendar years of 2020, 2021, 2022, 2023, and 2024. In addition, during the inspection, the PHMSA inspectors asked the Westgas personnel to conduct a test of the slam-shut valves at the Chalk Bluff station. It was noted that the Westgas system’s MAOP is 1000 psig with the slam-shut valves set to close at 950 psig. During the field test, the valves were found to not be in reliable working condition as one valve failed to close and the other closed at 1040 psig. Therefore, Westgas failed to inspect and test its pressure limiting devices to determine if they were in good mechanical condition, of adequate capacity, and in reliable operating condition, as required by § 192.739(a). Proposed Civil Penalty Under 49 U.S.C. § 60122 and 49 CFR § 190.223, you are subject to a civil penalty not to exceed $272,926 per violation per day the violation persists, up to a maximum of $2,729,245 for a related series of violations. For violation occurring on or after December 28, 2023 and before December 30, 2024, the maximum penalty may not exceed $266,015 per violation per day the violation persists, up to a maximum of $2,660,135 for a related series of violations. For violation occurring on or after January 6, 2023 and before December 28, 2023, the maximum penalty may not 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 $2,391,412 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#

52025026NOPV_Final Order_10142025_(24-297246)_text.pdf, page 6exceed $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. We have reviewed the circumstances and supporting documents involved in this case and have decided not to propose a civil penalty assessment at this time. Proposed Compliance Order With respect to Item 1 pursuant to 49 U.S.C. § 60118, the Pipeline and Hazardous Materials Safety Administration proposes to issue a Compliance Order to Westgas. Please refer to the Proposed Compliance Order, which is enclosed and made a part of this Notice. Response to this Notice Enclosed as part of this Notice is a document entitled Response Options for Pipeline Operators in Enforcement Proceedings. Please refer to this document and note the response options. All material you submit in response to this enforcement action may be 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). Following your receipt of this Notice, you have 30 days to respond as described in the enclosed Response Options. If you do not respond within 30 days of receipt of this Notice, this constitutes a waiver of your right to contest the allegations in this Notice and authorizes the Associate Administrator for Pipeline Safety to find facts as alleged in this Notice without further notice to you and to issue a Final Order. If you are responding to this Notice, we propose that you submit your correspondence to my office within 30 days from receipt of this Notice. The Region Director may extend the period for responding upon a written request timely submitted demonstrating good cause for an extension. In your correspondence on this matter, please refer to CPF 5-2025-026-NOPV and, for each document you submit, please provide a copy in electronic format whenever possible.#

52025026NOPV_Final Order_10142025_(24-297246)_text.pdf, page 7Sincerely, Dustin Hubbard Director, Western Region, Office of Pipeline Safety Pipeline and Hazardous Materials Safety Administration cc: PHP-60 Compliance Registry PHP-500 L. Salvador (#24-297246) Mr. Nathan Gonzales, Senior Engineer - Nathan.A.Gonzales@xcelenergy.com Enclosures: Proposed Compliance Order Response Options for Pipeline Operators in Enforcement Proceedings#

52025026NOPV_Final Order_10142025_(24-297246)_text.pdf, page 8PROPOSED COMPLIANCE ORDER Pursuant to 49 United States Code § 60118, the Pipeline and Hazardous Materials Safety Administration (PHMSA) proposes to issue to Westgas Interstate, Inc. (Westgas) a Compliance Order incorporating the following remedial requirements to ensure the compliance of Westgas with the pipeline safety regulations: A. B. In regard to Item 1 of the Notice pertaining to the annual inspection of each pressure limiting station, relief device, and pressure regulating station and its equipment, Westgas must inspect and test, and repair if necessary, the two slam- shut valves intended to protect against accidental over pressuring at the Chalk Bluff station to determine that they are in good mechanical condition, adequate from the standpoint of capacity and reliability of operation for the service in which they are employed, set to control at the correct pressure consistent with the pressure limits of § 192.201(a), and properly installed and protected from dirt, liquids, or other conditions that might prevent proper operation, and send documentation of the completed inspection and testing, including any required repairs, to the Director, Western Region within 60 days of receipt of the Final Order. It is requested (not mandated) that Westgas maintain documentation of the safety improvement costs associated with fulfilling this Compliance Order and submit the total to Dustin Hubbard, Director, Western Region, Pipeline and Hazardous Materials Safety Administration. It is requested that these costs be reported in two categories: 1) total cost associated with preparation/revision of plans, procedures, studies and analyses, and 2) total cost associated with replacements, additions and other changes to pipeline infrastructure.#