After regulators rejected key parts of a plan to improve the Red Hill fuel farm, the Navy responded that it continues “to firmly believe” that its repair proposal keeping single-wall tanks “provides a safe and effective approach” for ongoing operation of the facility, which was completed in World War II.

But the Navy also said that it has begun working with industry to see whether existing technology could provide some type of secondary containment.

Additionally, the Navy said it submitted a “justification supporting a funding request” for a $56 million water treatment facility to protect the Red Hill Shaft drinking water source below the fuel farm in what it calls the “unlikely scenario” of a significant fuel spill. The water shaft supplies Joint Base Pearl Harbor-Hickam.

The Office of Naval Research, meanwhile, has provided a $1.9 million grant to the University of Hawaii Applied Research Lab to design and test enhancements to the Red Hill Bulk Fuel Storage Facility’s prevention, detection and mitigation system.

The U.S. Environmental Protection Agency and state Health Department said in late October that the Navy proposal for improvements lacked “detail, clarity, rationale and justification.”

The Navy’s Nov. 23 response to the regulatory agencies notes that a “substantial amount of time” will be needed to answer their questions.

The preliminary response from the Navy also reflects a different tack for secondary containment. In its “tank upgrade alternatives” decision document from September 2019, the Navy said it would implement “double-wall equivalency secondary containment” — or remove fuel from Red Hill in approximately the 2045 time frame.

It also admitted that “although this technology does not currently exist to allow a fiscally-responsible approach, Navy is committed to finding a solution for secondary containment.”

The Nov. 23 response from the Navy now says it has begun working with industry to see whether “existing technology” can provide greater protection.

The Sierra Club of Hawaii continues to take a dim view of the Navy’s Red Hill remediation plan.

“This project should have never been built in this way in this place. It is a mistake to throw away more money on hopes and dreams for a fix, when there are none,” Director Marti Townsend said in an email.

Townsend called Red Hill a “Frankenstein that threatens to ruin our drinking water supply. The best thing they can do is retire the facility and relocate the fuel.”

“The sooner Navy officials can get their heads out of the sand about how dilapidated the Red Hill fuel tanks are, the sooner we can get down to the real work of protecting our drinking water source,” she added.

Located 2.5 miles from Pearl Harbor, the Red Hill Bulk Fuel Storage Facility consists of 20 vertically arrayed 250-foot-tall underground storage tanks that were started before the Dec. 7, 1941, attack on Oahu. The tanks were finished in 1943.

The facility, which the EPA said “is unlike any other in the United States,” can store up to 250 million gallons of fuel.

In response to a 27,000- gallon fuel spill in 2014 from Tank 5, the EPA and Health Department negotiated an enforceable agreement known as an Administrative Order on Consent requiring the Navy and Defense Logistics Agency to make infrastructure improvements.

Much of the concern centers on the tanks’ location 100 feet above the water supply aquifer — which lies in saturated volcanic rock — that the Sierra Club says is the principal source of drinking water for over 400,000 residents from Ha­lawa to Hawaii Kai.

The Navy says the Red Hill fuel tanks represent “critical infrastructure for the nation’s defense” and are quarter-inch steel backed by up to four feet of concrete and surrounding basalt. Beneath the tanks is 20 feet of concrete.

“Russia and China’s militaries have become increasingly aggressive and Red Hill provides the Defense Department ready access to fuel for needed mission readiness,” according to the Navy.

In late October, the EPA and Health Department said they disapproved the 2019 plan to protect groundwater near the site and were giving the Navy and Defense Logistics Agency “an opportunity to cure the deficiencies and resubmit the decision document.”

The Navy’s tank upgrade analysis had “not demonstrated to the regulatory agencies that the proposed alternative is the most protective of the groundwater and drinking water,” the notice stated.

The Navy selected the least expensive of six tank upgrade options and “the least protective,” according to the Sierra Club.

The Navy proposed a “comprehensive tank restoration” and decommissioning of nozzles that could be sources of leaks “combined with coating applications and improved testing, monitoring, modeling, sampling and analysis.” A lower portion of the tanks would be re-coated.

Also considered by the service were five other options, including keeping the single-wall steel liner while adding a full epoxy coating, as well as replacing the steel liner.

Double-wall options included new carbon steel with interior coating, a composite tank with stainless steel, and a carbon steel tank within a tank. Alternatively, a new tank farm also was contemplated.

In 2018 the Navy estimated the cheapest single-wall option would cost $180 million to $450 million. The tank-within-a-tank option was pegged at between $2 billion and $5 billion. Replacing the tank farm with similarly fortified underground or concrete-encased fuel tanks would run as much as $10 billion.

The term “double-wall equivalency” used by the Navy needs to be defined, the regulators said. Underground storage tanks with double walls are typically designed to meet secondary containment requirements, and secondary containment usually includes an inner and outer barrier with an in-between space monitored for leaks, the notice to the Navy said.

The Navy must provide a detailed comparison of how the proposed secondary containment equivalency will perform against other options, including traditional secondary containment such as tank within a tank, the agencies said.

The Honolulu Board of Water Supply said after the Navy proposed its tank upgrade alternative that the plan “does not provide adequate safeguards against future fuel releases.”

The Navy’s preferred single-wall tank upgrade alternative “is nowhere near equivalent to the actual secondary containment provided by a tank-within-a-tank structure,” the Board of Water Supply said.

The Navy said that since some the regulators’ questions would take longer to answer than others, it proposed to provide answers in series as they are completed.