Nineteen state lawmakers are calling for the Environmental Protection Agency to force the military to take more aggressive action to prevent further leaks at 20 underground jet fuel storage tanks at Red Hill that sit 100 feet above a major water aquifer.

The lawmakers, led by state Sens. Laura Thielen and Breene Harimoto, say a proposed consent order agreed to by the Navy, the federal Environmental Protection Agency and the state Department of Health doesn’t go far enough. In January 2014 one of the tanks at the Red Hill Bulk Fuel Storage Facility was discovered to have leaked about 27,000 gallons of jet fuel, raising concerns that the groundwater below might be contaminated.

While tests on drinking water samples since have been largely within acceptable federal and state levels, state and city leaders have voiced concerns about the continued use of the tanks without modifications, such as more monitoring wells or the double-lining of tanks.

Monday is the deadline for the public to comment on the proposed order, which calls for further study, more frequent testing and yet-to-be-determined upgrades to the tanks over the next two decades.

The lawmakers, in their July 8 letter to the EPA and the Health Department, warned that damage to the aquifer would be devastating islandwide, especially because the aquifer is used by the Honolulu Board of Water Supply to provide water needs to one-quarter of urban Honolulu.

Not only would contamination of that aquifer need to be tackled with extremely costly remedies, but also, “Oahu’s aquifers are interconnected, and the groundwater does, over time, migrate between these aquifers,” the letter said. “A catastrophic release of the jet and marine diesel fuel will devastate this island’s drinking water supply for generations.”

Thielen (D, Hawaii Kai-Waimanalo-Kailua) said the tanks should meet the EPA’s recently updated regulations for underground storage tanks, the first change in the regulations since 1988.

“We’re talking about secondary lining or the equivalent as far as the technology,” said Thielen, a former director of the state Department of Land and Natural Resources.

Thielen said she’s been told the regulation applies only to new underground tanks, not existing ones.

Navy officials have said putting a double lining around the tanks is among a number of options that can be considered.

Harimoto (D, Pearl Harbor-Aiea-Pearl City) has been pressing for more accountability.

“We waited a year and a half, since the original notice of the leak, for the Navy to negotiate this settlement,” Harimoto said. “And lo and behold, what do we find but the Navy has another two years to do a study, and then they have 20 years to implement a solution. That’s just totally not acceptable. There’s no sense of urgency.”

The Board of Water Supply has been demanding more monitoring wells be put in place in strategic places that can better detect contamination of the aquifer.

“But the Navy has been hemming and hawing about that,” he said.

The Navy has put in only two new monitoring wells since the incident, and “we need many more monitoring wells because it’s been established that there’s been ground contamination already,” Harimoto said.

Some may be suggesting that the cost of drastic improvements is prohibitive, “but when you weight the risks — if this contamination gets into the groundwater aquifer, there is no way to clean it up. At what cost are we weighing against?”

Tom Clements, spokesman for the Naval Facilities Engineering Command Pacific, said, “We’re prepared to put in more monitoring wells, but there is no immediate plans for any specific sites or number of wells.” Clements noted that the Navy has nine wells and an additional sampling point in the general area of the tanks.

As for the overall agreement, Clements said, “I think we’ve shown that we’ve taken appropriate action, and we are prepared to move out within the construct of this document.”

A Board of Water Supply spokeswoman said the agency is still preparing its response to the proposal. Last month Water Manager Ernest Lau called the proposed settlement “inadequate.”

City Council Resolution 15-162, introduced by Councilwoman Carol Fukunaga and adopted in a 8-0 vote last week, calls on the various state, federal and city agencies to implement recommendations made by a legislatively mandated Red Hill Fuel Storage Facility Task Force, including the installation of more monitoring wells, fortification of the fuel tanks and cleanup of existing groundwater contamination under the facility.