ENBRIDGE GAS OHIO — Warning Letter

party submissionOfficial PDF12025007WL_Operator Response to Notice_06192025_(24-303764).pdf#

12025007WL_Warning Letter_05232025_(24-303764)_text.pdf, page 1Official PDFWARNING LETTER VIA ELECTRONIC MAIL: michele.harradence@enbridge.com May 23, 2025 Ms. Michele Harradence President and Chief Executive Officer Enbridge Gas Ohio 500 Consumers Road 1201 East 55th Street Cleveland, Ohio 44103 CPF 1-2025-007-WL Dear Ms. Harradence: On May 23, 2024, and from June 11 to June 13, 2024, a representative of the Pipeline and Hazardous Materials Safety Administration (PHMSA) pursuant to Chapter 601 of 49 United States Code (U.S.C.) inspected Enbridge Gas Ohio’s (EGO) Stark-Summit Underground Natural Gas Storage in Stark, Ohio. 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. §192.12 Underground natural gas storage facilities. (a) … (c) Procedural manuals. Each operator of a UNGSF must prepare and follow for each facility one or more manuals of written procedures for conducting operations, maintenance, and emergency preparedness and response activities under paragraphs (a) and (b) of this section. Each operator must keep records necessary to administer such procedures and review and update these manuals at intervals not exceeding 15 months, but at least once each calendar year. Each operator must keep the appropriate parts of these manuals accessible at locations where UNGSF work is being performed. Each operator#

12025007WL_Warning Letter_05232025_(24-303764)_text.pdf, page 2must have written procedures in place before commencing operations or beginning an activity not yet implemented. EGO failed to follow its manual of written procedures for conducting activities under § 192.12(b).1 Specifically, EGO failed to follow its Storage Integrity Management Plan (SIMP), Section 33.5.6 Well Closure, during the plug and abandon of Well 1707 Serbian Church #3 which was performed in April and May 2023. EGO’s SIMP, Section 33.5.6 required that EGO correct deviations which may threaten isolation objectives of the plug. It also required EGO to determine the location of groundwater and hydrocarbon bearing zones penetrated by the well, determine the condition of the well’s casing and cement through those zones, and prevent communication between those zones from the plugging operation. Prior to the plug & abandon of this well, the annulus between the 3.5-inch production casing and the 5.5-inch intermediate casing had a pressure of 300 psi and gas sample analysis from 3/21/2023 confirmed it to be storage gas. During the inspection, the Daily Well Work Report pertaining to Well 1707 was reviewed. After the installation of plug #1 and plug #2, the report noted on 4/19/2023 that the annulus had a consistent pressure of 5 psi. EGO stated no annulus gas pressure was detected once plug #3 was installed from depth of 968 feet to 1311 feet. This information indicates that annulus gas pressure of 5 psi may be due to failure of plug #1 and plug #2 to achieve isolation from the storage formation. Failure of the plugs was not corrected prior to installation of plug #3 thereby allowing the possibility of storage gas communication with formations below plug #3. Additionally, EGO’s Gas Storage – Project Checklist, Project Type: Plug and Abandonment, section 6.7.2 Storage Zone Isolation required checking the following: Does the workplan include the condition of the well’s casing and cement across those zones, (utilizing available well and log records), to prevent communication between any of those during and after plugging the well. EGO stated a cement bond log of well 1707 was not done, thereby not utilizing log records in determining the condition of the well’s cement across groundwater and hydrocarbon bearing zones. Therefore, EGO failed to follow its SIMP, Section 33.5.6 Well Closure. 1 §192.12 Underground natural gas storage facilities. (a) . . . (b) Depleted hydrocarbon and aquifer reservoir UNGSFs. (1) . . . (2) Each UNGSF that uses a depleted hydrocarbon reservoir or an aquifer reservoir for natural gas storage and was constructed on or before July 18, 2017, must meet the provisions of API RP 1171 (incorporated by reference, see §192.7), sections 8, 9, 10, and 11, and paragraph (c) of this section, by January 18, 2018, and must meet all provisions of paragraph (d) of this section by March 13, 2021.#

12025007WL_Warning Letter_05232025_(24-303764)_text.pdf, page 3Under 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 $2,391,142 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. 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 • We advise you to correct the items) identified in this letter. Failure to do so will result in Enbridge Gas Ohio 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 1-2025-007-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#