ALYESKA PIPELINE SERVICE CO — Integrity Assurance Notification

REPAIRPer § 195.452(h)(3), Alyeska Pipeline Service Company (Alyeska) is notifying the Pipeline Hazardous Materials Safety Administration (PHMSA) of a delay of investigation and remediation of seven 180-day conditions discovered in segment 3 on April 19, 2022 at PLMP (pipeline milepost) 573.22, PLMP 684.52, PLMP 684.56, PLMP 758.98, PLMP 785.67, PLMP 785.89 and PLMP 767.52 of the Trans Alaska Pipeline System (TAPS). These locations reside in High Consequence Area Could Affect Segments (HCA CAS) which require scheduling for evaluation and remediation for Discovery of Condition per 49 CFR 195.452 (h)( 4 )(iii)(F): Predicted metal loss greater than 5 0% of nominal wall that is located at a crossing of another pipeline, or is in an area with widespread circumferential corrosion, or is in an area that could affect a girth weld), and 49 CFR 195.452 (h)(4)(iii)(H): Corrosion of or along a longitudinal seam weld. Details of the anomalies are listed in Table below. The investigation of these conditions is delayed due to an aggressive 2022 dig schedule that experienced delays from adverse rains and supply chain challenges and to avoid implementation of field activities during the coming hazardous winter working conditions. Investigations of discovery conditions will be completed at PLMP 767.52 by December 31, 2022, and at the remaining locations by December 31, 2023. These planned completion dates will allow time for implementation of field activities during seasons that are appropriately safe for the respective locations. A delay of investigation at these locations will not jeopardize public safety or environmental protection. The remaining wall thickness supports operating pressure. Operating pressures are also normally well below the MOP at these locations. Alyeska verified that there is adequate CP and will continue to monitor CP in these locations.#