The state Department of Health and the U.S. Environmental Protection Agency should consider the Navy’s request to close the Red Hill tanks “in place” only under the condition that the tanks be thoroughly cleaned and filled with fresh drinking water and maintained as reservoirs for as long as they remain in place.

In addition to creating new reservoirs for hundreds of millions of gallons of fresh drinking water, filling these tanks with fresh drinking water would assure they do not pose a risk to drinking water resources.

The Honolulu Board of Water Supply currently maintains dozens of steel tanks, drinking water reservoirs, on hillsides surrounding Honolulu. The Red Hill tanks could hold more water than all these tanks combined and, underground, the water would be protected.

If — or I should say when — they leak, they would then pose no risk to the Pearl Harbor aquifer or other sources of drinking water in the area. Water leaking from the tanks would then only serve to recharge the aquifer with fresh drinking water.

All the Red Hill tanks were all initially tested for tightness using fresh water. During construction in the 1940s, a worker drowned while working on one of the tanks and his body sank to the bottom. The deepest diving record anywhere at that time was achieved by the Navy diver who dove more than 200 feet to the bottom to retrieve the body of this unfortunate individual.

Filling the tanks with fresh water will help to assure that the Navy does not use them for fuel in the future or for other purposes that pose a threat to drinking water. It will also help to preserve the steel lining. One of the worst enemies of steel is oxygen, which promotes rust and enhances corrosion. If the tanks are filled with water, there would only be a small air space at the top of the tank. Degradation of the steel lining caused by rust and corrosion would be reduced considerably.

The only significant obstacle that stands in the way of repurposing the tanks from holding fuel to storing drinking water is the need to clean the tanks and surrounding support systems sufficiently to enable long-term water storage. This needs to be done regardless of what happens to the tanks. The Board of Water Supply would need to be consulted in this regard. Requiring that the tanks and the distribution system to be cleaned to a point where there is no residual fuel will assure there is no future contamination of groundwater from leaks.

Using the Red Hill tanks to hold precious drinking water for emergencies and other uses would be far less costly than removing the tanks. The bulk of the costs would be associated with cleaning the tanks and the fuel distribution system, not unearthing thousands of tons of steel and concrete previously used to support defense activities.

What a shame it would be to destroy this engineering marvel — years of hard work by hundreds of engineers, steel workers and others — when these tanks could so easily be repurposed to better meet Hawaii’s future needs.

Bruce S. Anderson, Ph.D., M.P.H., is former director of Hawaii’s Department of Health.