Raleigh, N.C. — Firefighters have tapped into new water sources as they battle a blaze that has burned nearly 42,000 acres in three eastern North Carolina counties over the past seven weeks.

Officials had hoped Tropical Storm Cristobal would dump enough rain to make a dent in the Evans Road Wildland Fire, which is about 75 percent contained. However, the storm only dropped an average of 0.6 inches on the fire.

"This fire has been likened to a charcoal grill where you have the coals just glowing and continue to glow. And even when we get some rain on the area, the heat is still there," said Bruce MacDonald, with the North Carolina Forest Service.

A quarter of the fire still burns in inaccessible areas of the Pocosin Lakes National Wildlife Refuge, west of N.C. Highway 94 around Columbia in Tyrrell County.

Underground fires fed by peat are another problem for firefighters. To combat those, crews have started piping billions of gallons of water into the local canal system.

Forestry officials say the process is slow and expensive, but gets at the underground sources that have kept the wildfire going.

"Well, you know, we're always going to be scaling back to save costs," said Nigel Baker, a spokesman for the Florida Division of Forestry. "That's an issue with every state and with every agency."

Crews from Florida and Kentucky are among the more than 275 firefighters continuing to battle the blaze. A lightning strike sparked the conflagration on June 1.

"Until we get some significant rainfall, until we're out of this drought season that we're currently in or we get some snowfall, we're going to be here a long time," Baker predicted.