BROOKS – Environmental workers faced a daunting task Monday as they rushed to recover 5,600 gallons of oil that spilled from a wrecked tanker truck into an 87-acre pond northwest of Belfast.

“This is quite a mess,” said Peter Blanchard, spokesman for the Department of Environmental Protection Response Services Division at Sanborn Pond, which is off Route 137 in southern Brooks and near the towns of Knox and Waldo.

“It’s going to take a lot of time to clean it up, and it’s going to take a long time for the pond to get back to normal,” Blanchard said.

The spill occurred at 8 p.m. Sunday when a tractor-trailer carrying 8,600 gallons of No. 6 Bunker C oil broke through a guardrail, leveled a camp and came to rest inches from the pond. The oil is used in the big boilers at the Sappi Fine Paper North America mill near Skowhegan.

The oil tanker was impaled and gouged open by the metal guardrail. An estimated 5,600 gallons of the thick, black ooze poured into the pond and spread quickly across most of its surface.

The truck, owned by H.O. Bouchard of Hampden, was a total loss. Driver James Tripp, 46, of Brewer told authorities he swerved to avoid a deer and lost control. Tripp was headed west and riding on the shore side of the road when he wrecked. Tripp suffered cuts to his face and numerous other cuts and bruises. He was taken by ambulance to Waldo County General Hospital for treatment.

Tripp lost control on the first of a series of switchback curves that take the road within yards of the pond’s shore.

The truck caught the right shoulder and pushed back 100 feet of guardrail before it left the road and plowed into the camp.

The small wood-frame camp, one of two on that stretch of road owned by Massachusetts resident Art Green, was uninhabited. It was a total loss.

“He went right through it,” Blanchard said.

Blanchard said a quick response by the Brooks Fire Department managed to keep the entire load of oil from spilling into the pond.

He said an estimated 3,000 gallons of the cargo was pumped into a second truck and taken from the scene.

Tripp had filled his truck earlier Sunday at the port in Searsport and was on his way to the paper mill in Hinckley, just below Skowhegan, according to Ken Beal, H.O. Bouchard comptroller. Beal said the company was insured for accidents and was responsible for the cleanup.

Beal said the company retained the services of hazardous-products removal firm Clean Harbors to handle the cleanup.

Waldo County Emergency Management Agency director Rick Farris said the workers were “doing a good job, considering what they have in front of them.” Farris declined to estimate the cost of the cleanup. “It’s going to be very expensive. There’s a lot of work here.”

The DEP’s Blanchard said most of the pond was ringed with absorbent booms by early morning. Booms also were positioned at the pond’s outlet stream, the narrows where it joins with Duttons Pond and a cove on the far side that workers managed to seal off before the slick reached its shores.

Blanchard said more than 80 percent of the pond and its shoreline was affected by the spill.

Two DEP boats designed to skim the surface and collect oil were put into service early Monday. The boats separate oil from water and the collected oil is later offloaded onto trucks. Blanchard declined to speculate how long it would take to clean the surface, but he said the spill was the largest into a body of fresh water in memory.

“It’s going to take several days, maybe weeks, and the follow-up inquiry will be months,” he said.

Blanchard noted that while the spill was extensive, No. 6 oil is less toxic than heating oil. He also said the oil has a tendency to sink more rapidly than other petroleum products. Blanchard said DEP’s Water Quality Bureau would make an assessment of the pond in the coming days in an attempt to forecast the long-term effects of the spill.

“It’s difficult to say what the impact is at this time, but it’s certainly a major spill,” said Blanchard.

Sanborn Pond is a popular swimming hole in summer and is treasured year-round by fishermen. It supports healthy populations of bass, brook trout and brown trout. It ranges in depth from shoreline shallows to 66 feet.

As workers skimmed the pond for oil, a pair of loons, apparently unaware of the deadly sheen, dove for food and paddled across the surface.

Route 137 was shut down within moments of the crash Sunday night, and traffic was rerouted around the area for 12 hours. The road was reopened early Monday, with traffic allowed to pass in intervals. Excavators were called to the scene to remove the portion of the oil-drenched shoreline where the spill occurred.

Sanborn Pond resident Julie Schlachter arrived home within an hour of the accident and saw firsthand the devastation of what was once a pristine environment. She said the slick was already extensive and the stench of oil permeated the country air.

“It was terrible,” Schlachter said Monday. “All the water is polluted. It’s very, very sad.”