Battling a fire in the Great Dismal Swamp has cost the federal government $4 million so far.

U.S. Fish and Wildlife Service spokeswoman Catherine Hibbard says the fire is 70-percent contained. But she says it will continue to smolder and its acrid smoke won't go away any time soon.

Hibbard says firefighters are pumping in water from ditches around the swamp to dampen the ground, which will help hold down the smoke.

The blaze has burned 3,474 acres since it started June 9 when a piece of timbering equipment caught fire.

The fire has wiped out parts of a project to restore Atlantic white cedar trees.