COLUMBIA MIDSTREAM GROUP, LLC — Notice of Amendment

120176008M_Closure Letter_0302018_text.pdf, page 1Official PDFOVERNIGHT EXPRESS DELIVERY March 2, 2018 Mr. Stanley Chapman III President, US Gas Pipelines Columbia Midstream Group, LLC 700 Louisiana Street, Suite 700 Houston, TX 77002 CPF 1-2017-6008M Dear Mr. Chapman: From April 24-28, 2017, a representative of the Pipeline and Hazardous Materials Safety Administration (PHMSA) pursuant to Chapter 601 of 49 United States Code inspected the procedures and records of Columbia Midstream Group, LLC, a subsidiary of TransCanada (TransCanada), at its pipeline facility located in Leetonia, Ohio. As a result of the inspection, TransCanada was issued a Notice of Amendment (NOA) dated December 14, 2017. In response to the NOA, TransCanada discussed updates and changes to multiple procedures; however, these procedures were not incorporated for review in the response letter on February 12, 2018. Subsequently, PHMSA granted an additional 30 days for TransCanada to respond to the NOA and provide the updated procedures. TransCanada submitted its revised procedures on March 1, 2018. PHMSA has reviewed the amended procedures, and it appears that the inadequacies outlined in this NOA have been corrected. This letter is to inform you that no further action is necessary, and this case is now closed. Thank you for your cooperation. Sincerely, Robert Burrough Director, Eastern Region Pipeline and Hazardous Materials Safety Administration#

120176008M_Notice Of Amendment_12142017_text.pdf, page 1Official PDFNOTICE OF AMENDMENT OVERNIGHT EXPRESS DELIVERY December 14, 2017 Mr. Stanley Chapman III President, US Gas Pipelines Columbia Midstream Group, LLC 700 Louisiana Street, Suite 700 Houston, TX 77002 CPF 1-2017-6008M Dear Mr. Chapman: From April 24-28, 2017, a representative of the Pipeline and Hazardous Materials Safety Administration (PHMSA) pursuant to Chapter 601 of 49 United States Code inspected the procedures and records of Columbia Midstream Group, LLC, a subsidiary of TransCanada (TransCanada), at its pipeline facility located in Leetonia, Ohio. On the basis of the inspection, PHMSA has identified the apparent inadequacy found within TransCanada’s plans or procedures, as described below: 1. § 195.402(c)(3) (C) Maintenance and normal operations. The manual required by paragraph (a) of this section must include procedures for the following to provide safety during maintenance and normal operations: (3) Operating, maintaining, and repairing the pipeline system in accordance with each of the requirements of this subpart and subpart H of this part. TransCanada’s procedures for operating, maintaining and repairing the pipeline system in accordance with each of the requirements of this subpart and subpart H of Part 195 were inadequate for overpressure safety devices. Specifically, TransCanada’s procedures failed to provide sufficient guidance on how to conduct and document relief valve inspections, per § 195.428(a). Section 195.428(a) states: “(a) Except as provided in paragraph (b) of this section, each operator shall, at intervals not#

120176008M_Notice Of Amendment_12142017_text.pdf, page 2CPF 1-2017-6008M exceeding 15 months, but at least once each calendar year, or in the case of pipelines used to carry highly volatile liquids, at intervals not to exceed 7½ months, but at least twice each calendar year, inspect and test each pressure limiting device, relief valve, pressure regulator, or other item of pressure control equipment to determine that it is functioning properly, is in good mechanical condition, and is adequate from the standpoint of capacity and reliability of operation for the service in which it is used.” During the inspection, the PHMSA inspector reviewed TransCanada’s “Liquid Overpressure Safety Devices and Overfill Protection Plan”, dated 8/30/16 (Plan), “Liquid Pipeline Relief Valve Setpoint Test/Capacity Review Procedure”, dated 6/10/16 (Procedure), and relief valve inspection records (Record). TransCanada’s Plan and Procedure did not provide sufficient guidance on conducting and documenting a relief valve inspection. To ensure that a relief valve will relieve at the specified set pressure when needed, data is needed on the condition of the valve prior to the inspection (“as found”), as well as on the condition of the valve after the inspection is completed (“as left”). Information typically documented includes:  The relief pressure of the valve in the “as found” condition  The relief pressure of the valve in the “as left” condition  The “set point” TransCanada’s Plan and Procedure did not include sufficient guidance and criteria for capturing either the “as found” or “as left” pressure of a relief device, as the terms are not defined. The Plan states in Section 3: “Documentation: … Equipment maintenance records for mechanical pressure relief valves (thermal relief and pressure relief valves) records should include: … e) As found and as left set point pressure of the device.” The Procedure provides guidance for documenting various pressure reading values during the performance of a relief valve inspection. None of the values required by the Procedure are stated to be the “as found” or “as left” relief pressure required to be documented per the Plan. The Records reviewed demonstrated inconsistency with the Plan, as no fields were defined for “As Found” or “As Left” relief pressure. In addition, the Plan/Procedure lacked details such as, but not limited to:  The criteria for determining acceptable “as-found” / “as left” relief pressures  The actions that must be taken if the relief valve “as-found” pressure does not meet the criteria  The definition and criteria for determining “popping pressure”, “popping point”, “reseat pressure”, “set pressure”. 120176008M_Notice Of Amendment_12142017_text Page 2 of 3#

120176008M_Notice Of Amendment_12142017_text.pdf, page 3CPF 1-2017-6008M Therefore, TransCanada failed to provide sufficient guidance on how to conduct and document relief valve inspections, per the requirements of § 195.428(a). Response to this Notice This Notice is provided pursuant to 49 U.S.C. § 60108(a) and 49 C.F.R. § 190.206. Enclosed as part of this Notice is a document entitled Response Options for Pipeline Operators in Compliance Proceedings. Please refer to this document and note the response options. 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). Following the receipt of this Notice, you have 30 days to submit written comments, revised procedures, or a request for a hearing under §190.211. 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 an Order Directing Amendment. If your plans or procedures are found inadequate as alleged in this Notice, you may be ordered to amend your plans or procedures to correct the inadequacies (49 C.F.R. § 190.206). If you are not contesting this Notice, we propose that you submit your amended procedures to my office within 60 days of receipt of this Notice. This period may be extended by written request for good cause. Once the inadequacies identified herein have been addressed in your amended procedures, this enforcement action will be closed. It is requested (not mandated) that TransCanada maintain documentation of the safety improvement costs associated with fulfilling this Notice of Amendment (preparation/revision of plans, procedures) and submit the total to Robert Burrough, Director, PHMSA Eastern Region, 820 Bear Tavern Road, Suite 103, West Trenton, NJ 08628. Please refer to CPF 1- 2017-6008M on each document you submit, and whenever possible provide a signed PDF copy in electronic format. Smaller files may be emailed to robert.burrough@dot.gov. Larger files should be sent on a CD accompanied by the original paper copy to the Eastern Region Office. Additionally, if you choose to respond to this (or any other case), please ensure that any response letter pertains solely to one CPF case number. Sincerely, Robert Burrough Director, Eastern Region Pipeline and Hazardous Materials Safety Administration Enclosure: Response Options for Pipeline Operators in Compliance Proceedings 120176008M_Notice Of Amendment_12142017_text Page 3 of 3#