Kirtland Air Force Base must do more to identify the extent of a decades-old underground fuel leak and clean it up before it reaches nearby drinking water wells, officials with the New Mexico Environment Department said today.

In a news release, department Secretary Ron Curry said the state has required the Air Force to drill five additional wells to determine the size of the underground jet-fuel plume, which was discovered in 1999 but was only made public in July. The cleanup plan also requires the Air Force to speed up its ongoing remediation process by installing additional equipment.

Kirtland officials told the New Mexico Independent last month that the fuel may have started leaking 50 years ago, but that they don’t know exactly when it started. Since then, the fuel has leached into the water table and migrated toward several drinking wells operated by Kirtland itself, the city and the U.S. Veterans Administration. To date, Kirtland has removed an estimated 130,000 gallons of fuel by sucking the vapor out of the fuel-saturated ground and burning it in two large engines.

The environment department has been monitoring the Kirtland clean-up plan, said Deputy Secretary Jon Goldstein. The new requirements are not an indictment of the Air Force’s efforts, he said. “This is just part of our aggressive effort to get this cleaned up.”

Kirtland had already been required to drill additional wells. The work plan approved by the state this week requires five additional wells to to the size and scope of the plume, said Bill Olson, the department’s Water Quality Bureau chief. And new wells could be required beyond those if the first set doesn’t find the edge of the jet fuel, he said.

Once Kirtland defines the extent of the plume, Olson said, the base must submit a full-scale remediation plan. The department will take public comments on the proposal before deciding whether to approve it.

In addition, the base must install a second set of engines to burn up fuel found floating above the water in a monitoring wells. As vapor from the fuel is vacuumed out, Olson said, the fuel is expected to evaporate.

“We believe this is really going to speed things up considerably,” said department spokeswoman Marissa Stone.

Until the plume’s size is determined, it isn’t clear how long the cleanup will take, Goldstein said. But in the meantime, water quality is not threatened, he said. “The wells are safe — we can say that with certainty,” he said, and continual monitoring ensures that the jet fuel could not reach the drinking water without being detected.