A Sand Island tank farm operator was aware on Dec. 22 that a jet fuel tank had a drop in fuel levels, but didn’t report it to authorities until a full month later, after the tank lost 42,000 gallons of fuel, which had leached into the ground, an Environmental Protection Agency spokesman confirmed Friday.

The operator, Aircraft Service International Group, told the state Department of Health and the National Response Center of the fuel spill Jan. 21, and DOH notified the public Jan. 28, a week later, EPA said.

Carroll Cox, president of EnviroWatch, who has been monitoring the response, said officials from the U.S. Department of Transportation’s Pipeline and Hazardous Materials Safety Office assured him by phone they will arrive in Honolulu March 9 to investigate the matter.

The state’s on-site coordinator did not return calls about whether the state was notified of the possible leak in December.

EPA spokesman Dean Higuchi said he could not provide any details on when and how much had leaked before Jan. 21 and what monitoring devices showed, if anything, but said ASIG notified authorities when it could confirm the spill, which is appropriate.

Higuchi said it’s not necessary to inform the agencies when a discrepancy in fuel tanks occur, which can happen daily with fluctuations due to heat expansion and cooling.

From what EPA officials were told, the company removed the fuel, cleaned and vented the 2.8-million gallon capacity tank, then inspected it. When a section of the tank bottom was removed, fuel was visible on the ground, and that’s when the release of fuel was confirmed, Higuchi said.

Now the state Department of Health and the EPA are trying to recover as much of the jet fuel before it seeps into the ocean, just 150 feet away, but the fuel has already contaminated soil and groundwater to a depth of 2 to 3 feet.

The state is using private contractors, and crews had recovered 18,640 gallons of the spilled jet fuel as of Thursday, the EPA reported, adding the fuel recovery amount was revised to account for dewatering.

A plan to create an interceptor trench to ensure the plume of jet fuel does not reach near-shore waters has been completed.

The companies have a March 2 deadline to submit a plan for confirmatory sampling the cleanup is complete.

"The priority is to address the spill," Higuchi said. "Once that’s accomplished, the attention will turn back to why this happened, how it happened."

The state’s on-site coordinator, Terry Corpus, had said ASIG discovered a welded portion at the bottom of the tank had failed, and fuel was leaking through.

Cox said the recovery work is too slow, given the large size of the spill and the proximity to the ocean. He said a much smaller, 9,500-gallon fuel spill case in Wisconsin has a $19 million cleanup cost at last check.

Cox also complained the Health Department is "quick to tell you no drinking water is threatened," but groundwater at the ocean’s edge is just as important to the environment.

"This has migrated in the groundwater just yards away from the shoreline," he said, adding it is made worse because of the tidal influx, storm surge, and rain that have the potential to cause fuel to percolate to the top.

Cox also said there is no effort underway to extract the fuel from the soil.

"How do we address the contamination of that soil?" he said. "We’re treating the environment too recklessly."

Higuchi said the response cycle is determined by its on-scene coordinators, and is based on efficiency and safety, which working during daylight hours provides.

He said the EPA was notified Jan. 21, and it sent out on-site coordinators from San Francisco, who arrived Jan. 25 and started work Jan. 26.

"That’s when we started mobilizing," he said, and the EPA took the lead in the work.