The Navy has reached an agreement with federal and state regulatory agencies to improve technology aimed at better preventing and detecting fuel leaks at its Red Hill Bulk Storage Facility following last year’s spill of an estimated 27,000 gallons of aviation fuel from one of its World War II-era tanks.

Although pleased that progress is being made to address the matter, lawmakers who represent Red Hill communities expressed concern that more immediate action was not being taken.

Under terms of the proposed agreement, announced Monday by the U.S. Environmental Protection Agency and the state Department of Health, all upgrades must be approved by the two regulatory agencies and monetary penalties may be imposed if the work does not meet specified terms.

As part of the agreement, a feasibility study, to be submitted within two years, will look at a range of tank upgrade options. Each of the underground storage tanks that are in-service will be upgraded in phases over the next 20 years. Also, the Navy will double the frequency of its tank testing to annual from biennial, the agencies said.

Public comment on the proposal is being accepted for 30 days and a public meeting on the agreement is slated for June 18. After reviewing public comments, EPA and DOH may sign the agreement to make it effective or seek to modify it based on information received during the comment period.

Sen. Breene Harimoto (D, Pearl Harbor-Pearl City-Aiea) said: "I am happy that they finally got this to a conclusion with the agreement, after over a year, but on the other hand I’m not too pleased that there seems to be very little immediate action. It’s a two-year feasibility study and it’s already over a year since the spill was reported.

"I was really hoping for a much more immediate response."

Honolulu City Councilman Brandon Elefante, whose district includes Aiea, Pearl City and Waipahu, said he is pleased that an agreement has been reached, but he still has some concerns.

"I’m pleased that we’re making progress," Elefante said. "We still need to have attention to the issue because our water resource is very important, and my hope is that people are aware of what’s going on."

Elefante said he would like to see the tanks secured with double-lining materials to further prevent groundwater contamination.

Navy Region Hawaii, in a written statement, said the agreement "provides an engineering-based roadmap for the operation of Red Hill, and the Navy and (Defense Logistics Agency) are ready to move forward within the framework of this consent order. In doing so, we can improve the protection of drinking water, while preserving a strategic asset."

In January 2014, about 27,000 gallons of jet fuel leaked from one of the 20 tanks under Red Hill. Water wells at the nearby Halawa and Moanalua shafts provide about 25 percent of the drinking water for urban Honolulu. The Board of Water Supply has found no signs of contamination in the water supply around Red Hill.

Cost estimates will be pinpointed after the feasibility study, but the upgrades are expected to run into the "tens of millions of dollars," the agencies said.

Keith Kawaoka, the state DOH’s deputy director of environmental health, said in a statement: "The Department of Health is committed to taking measures required to prevent the future releases from all underground storage tanks."

Jared Blumenfeld, the EPA’s regional administrator for the Pacific Southwest, said the EPA and DOH would remain vigilant during the long-term to protect Hawaii’s residents and its water systems. "This agreement will ensure the safety of Oahu’s drinking water supply, while allowing the Red Hill tanks to remain in use as a resource for our national defense," Blumenthal said.

Also as part of the agreement, within the next two years the Navy and the Defense Logistics Agency will conduct an analysis of the groundwater geology of the area surrounding the Red Hill facility, study the extent of contamination caused by previous fuel releases, evaluate potential cleanup methods and assess the risk the facility poses to Oahu’s drinking water resources.

Additional groundwater monitoring wells may be required between the Red Hill tanks and the Honolulu Board of Water Supply’s drinking water wells, officials said.

Three members of Hawaii’s congressional delegation also expressed optimism about the agreement.

"The proposed agreement between the EPA, the Hawaii state Department of Health, and the U.S. Navy will help reduce the risk of future fuel leaks at the Red Hill facility and protect our drinking water," U.S. Sen. Brian Schatz said in a statement. "It also ensures that the Navy will continue to operate this strategic fuel depot in the Asia Pacific while continuing to meet its commitment to be good environmental stewards to the people of Hawaii."

U.S. Rep. Mark Takai said he is heartened to see much-needed upgrades planned for the Red Hill facility. "Providing long-term integrity and environmental security for the Red Hill Underground Fuel Storage Facility is critical to protecting the freshwater supply of the surrounding communities," Takai said in a statement.

U.S. Sen. Mazie Hirono described the agreement as a pathway to minimize the risk of future leaks.

"With the (agreement), we have assurance that the military will make continued investments at the facility under the regulatory authority of EPA and HDOH, who will approve all work timelines and potential penalties for noncompliance."