2015 AOC Tank Infrastructure Improvements: Corrosion and Metal Fatigue Practices
The tanks at Red Hill are constructed of concrete with an internal lining of steel ranging in thickness from 1/4 inch to 1/2 inch. Each tank lining consists of hundreds of steel plates, connected by thousands of feet of welds. The steel lining was originally installed at the time of the tanks' construction in the early 1940s. Evaluating the condition of these plates is critical in determining the tanks’ ability to store fuel. The condition of the existing steel is also important in determining the suitability of various tank upgrade alternatives.
To date the Navy and Defense Logistics Agency have submitted several reports and plans required by the 2015 Red Hill Administrative Order on Consent regarding the condition of the tanks’ steel liners. The Corrosion and Metal Fatigue Practices Report, submitted in April 2016, describes the Navy’s current practices for assessing the condition of the steel used in the tanks and associated fuel containment infrastructure.
Destructive Testing Results Report and Joint Regulatory Agency Response
In June 2018, small samples of steel and concrete were physically removed from one of the Red Hill tanks (Tank #14) to determine whether the tank maintenance program can accurately predict the presence of corrosion before repairing tanks and bringing them back into service. These samples were visually inspected and then sent to a laboratory for more thorough analysis. The results of this exercise are available in the Navy’s Destructive Testing Results Report which is available for viewing below.
The Regulatory Agencies disapproved the Destructive Testing Results Report because EPA and Hawai'i Department of Health (DOH) do not concur with the finding that the destructive testing validated the non-destructive testing (NDE) process specific to the Red Hill tanks.
The Regulatory Agencies required the Navy to conduct further evaluation and improvements to the tank inspection process. In response, the Navy’s submitted a revised Execution Plan that describes a suite of corrosion and tank integrity-related studies that will lead to recommended improvements to the Red Hill tank inspection, repair and maintenance procedures. For details, please see the reports and correspondence below.
Documents
- Section 5.4 Execution Plan: Decision on Need for and Scope of Modified Corrosion and Metal Fatigue Practices Amendment #1 (REDACTED) (pdf)
- Regulatory Agencies Response to Navy's December 4, 2020 Execution Plan (pdf)
- Section 5.4 Execution Plan: Decision on Need for and Scope of Modified Corrosion and Metal Fatigue Practices (REDACTED) (pdf)
- Regulatory Agencies Response to Navy's June 2, 2020 Letter (pdf)
- Navy's Response to Regulatory Agencies Disapproval of March 16, 2020. (pdf)
- Joint Regulatory Agency Response to Corrosion and Metal Fatigue Practices, Destructive Testing Results Report (pdf)
- Destructive Testing Results Report (pdf)
- Revised Conditional Approval of Destructive Testing SOW - August 2017 (pdf)
- Red Hill Destructive Testing Scope of Work (pdf)
- Additional Documents