FOLSOM — A forest fire in western Atlantic County may have started from a burning debris pile, but the remote blaze is being investigated as a possible arson.

Firefighters initially suspected the fire’s cause was lightning, which can take days to weeks to fully ignite, said acting State Fire Warden Michael Drake. However, Drake said that firefighters discovered a debris pile near where the fire originated and that has now led investigators to deem the fire suspicious in nature.

The fire is being investigated for possible arson, New Jersey Department of Environmental Protection spokesman Larry Hajna.

Drake said the fire, which encompasses about 115 acres, was reported this morning by a crop duster in the area. When forest firefighters found the blaze, it already had burned about 25 acres. The burn area was expanded to about 115 acres because firefighters will use existing fire roads in the area to isolate and control the blaze, Drake said.

It was contained as of 5:30 p.m. at 130 acres, officials confirmed.

The fire is being called the “Penny Pot” fire due to its proximity to Penny Pot Park.

Hot weather and dry conditions are helping fuel the fire, but predicted light winds are assisting firefighters, who are back-burning sections of the pinelands in the containment area to reduce the amount of explosive fuel. However, Drake said, the fire won’t be completely out until there is a heavy rain on the contained area.

The fire is about a half-mile into the woods off Eighth Street near Route 322 and mostly contained in Folsom. Smoke is drifting across a section of Eighth Street closest to the fire. A smoke plume can be seen as far east as Egg Harbor Township.

“It’s in a remote area, so they’re working to put lines around it,” said Assistant Division Warden Ken Badger. “At this time, there’s no threat to any dwellings or anything like that.”

This spring’s fire season was relatively intense, as unseasonably warm temperatures combined with high winds and moderate drought conditions to create a dangerous tinderbox in many parts of the state. The fire danger was reduced as trees and undergrowth came into leaf and rains helped increase soil moisture.

However, Drake said he predicted this spring that the state would have a fire season this summer and since last week, crews have been battling a number of small forest fires, he said.

Thursday, fire crews gradually worked along a sand road, lighting the brush into the wind. Flames quickly grew and climbed up trees, but as the fuel source was burned, flames died back. Areas that already had burned were still smoldering, with smoke rising up and seeming like fog over blackened ground.

Portions of South Jersey are considered as “abnormally dry,” according to the National Drought Monitor and fire crews said the area of the pine barrens is relatively dry for this time of year.

Staff writer David Simpson contributed to this report.