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 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.

In May 2017, the Navy and Defense Logistics Agency submitted the “Red Hill Destructive Testing Scope of Work”, which details their plan to conduct destructive testing on the steel used in one or more of the tanks (available for viewing below). This Scope of Work was approved by EPA and the Hawaii Department of Health in August 2017, subject to certain conditions. This conditional approval letter is available for viewing below.

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. EPA and the Hawaii Department of Health are currently reviewing the laboratory data (available for viewing below) with the assistance of external corrosion and tank industry experts. The Navy’s interpretation of these laboratory results, an initial assessment of their ability to find flaws within the Red Hill tanks, and additional corrosion and metal fatigue related work is due in a final report to be submitted to the Regulatory Agencies on July 7, 2019.

Documents

• Laboratory Analysis of Tank 14 Samples (PDF)(149 pp, 31 MB, 2/15/2019)
  This lab report contains raw data and pictures of samples removed from Tank 14
• Field Notes Taken During the Removal of Coupons from Tank 14 (PDF)(20 pp, 1 MB, 06/20/2018)
  Field observations recorded during the deliberate removal of steel and concrete samples from Tank 14.
• Revised Conditional Approval of Destructive Testing SOW - August 2017 (PDF)(6 pp, 3 MB, 08/10/2017)
  Revised conditional approval by EPA and DOH of Destructive Testing Scope of Work.
• Red Hill Destructive Testing Scope of Work (PDF)(35 pp, 615 K, 05/30/2017)
  Plan to conduct destructive testing at the Red Hill Facility. May 30, 2017