William Mott Archives | Page 2 of 2 | Prince William Sound Regional Citizens' Advisory Council

Crude Oil Storage Tank Vent Snow Damage

In March of 2022, snow accumulated on Alyeska Pipeline Service Company’s crude storage tanks at the Valdez Marine Terminal and damaged several of the tank pressure vacuum pallets (or vents). The vent damage caused a leak of crude oil vapor from inside the tanks. This report by Taku Engineering summarizes their independent investigation of the damage, the associated vapor release, Alyeska’s response, and the proposed repair methods.

Follow-up report, released in December 2024: 2022 Tank Pressure/Vacuum Pallet Damage: Crude Oil Storage Tank Headspace Gas Assessment

Download the report:

Crude Oil Storage Tank 8 Floor and Cathodic Protection System Design Review

The study resulted in the development of a number of findings and recommendations. General findings and recommendations are discussed in the executive summary. Detailed discussions are provided in Section 3.

Crude Oil Storage Tank 8 Maintenance Review

After some concerning findings during a 2019 internal inspection of Tank 8, Alyeska planned to replace the tank floor and cathodic protection (CP) system in 2020. However, the COVID-19 pandemic delayed those major repairs. The tank will be removed from service in 2023, at which time the floor and CP system will be replaced. Significant findings of this study include: The risk of a leak from Tank 8 between now and 2023 is low; Water may be accumulating under the tank floor because of an unmaintained exterior seal. This could damage the tank’s floor, Data used to ensure that Tank 8’s CP system is operating effectively is not being collected properly. Detailed findings and recommendations are in the final report.