Photo: The Canadian Press

UPDATE: 6:35 P.M.

About 90 per cent of a peat bog south of Vancouver is expected to regenerate in the coming years, but it could take a century before the entire area recovers from a fire that tore through it on Monday, says the head of a conservation society.

Eliza Olson, founder of the Burns Bog Conservation Society, said the 30-square-kilometre nature reserve in Delta is believed to be the largest undeveloped urban wilderness area in North America.

"That's one of the beauties of having Burns Bog here in the water table," she said in an interview Monday.

"Because it's at the mouth of the Fraser River, it's an estuary-raised bog. You normally don't find a raised bog this far south."

A fire reported at Burns Bog on Sunday was about 50 per cent contained by Monday afternoon, with crews hoping to fully contain the flames by Tuesday morning at the latest.

Chief Dan Copeland of the Delta Fire Department said the blaze was 78 hectares in size, and about 80 firefighters from a number of jurisdictions were battling the fire.

How the fire started was unclear, he said, but a team of investigators from the Delta Fire Department and B.C. Wildfire Service were working to determine the cause.

Burns Bog is one of North America's largest peat bogs and flames can sink under the dry peat, where they burn out of sight.

But ground conditions and a quick response from firefighters kept the flames from burrowing beneath the peat, Copeland told a news conference Monday afternoon.

"We were able to get to it quick enough and soak it down so it didn't get deep into the peat," he said.

Fighting the fire is still tricky, he added, because of the area's soggy terrain.

Delta police have said it could take at least a week to extinguish the fire.

An evacuation order for businesses near the blaze was scheduled to be lifted Monday night. Highway 17, a major thoroughfare that cuts through Delta, was expected to remain closed from Highway 99 to the Highway 91 connector for several days.

Mayor Lois Jackson said the fire is a "major emergency" and the community was under provincial emergency status.

She said Metro Vancouver was monitoring air quality as smoke had drifted into Vancouver, but conditions improved since Sunday and it had not issued a general advisory.

UPDATE: 4:20 p.m.

A fire burning in a suburban Vancouver conservation area is now about 50 per cent contained.

Chief Dan Copeland of the Delta Fire Department says crews have made significant progress on the fire in Burns Bog and hope to have it fully contained by Tuesday morning at the latest.

The 78-hectare blaze started Sunday morning and there were concerns flames could sink under the dry peat and burn out of sight.

But Delta Mayor Lois Jackson says crews have determined the fire did not go underground because crews responded quickly.

Delta police Chief Neil Dubord says an evacuation order for a nearby industrial area will be lifted Monday night.

The flames and heavy smoke prompted police to close a portion of Highway 17 because of the fire, and Dubord says those road closures are expected to remain in place for several days.

UPDATE: 8:45 a.m.

The Burns Bog fire southeast of Vancouver has been 10 per cent contained, with crews hoping to fully contain the flames by the end of Monday.

Delta fire Chief Dan Copeland says the blaze is between 50 and 70 hectares in size, and 80 firefighters are battling the fire.

Copeland says one firefighter is being treated in hospital after suffering from a medical condition, but he declined to give further details.

Delta Mayor Lois Jackson says the fire is a "major emergency," and the community is under provincial emergency status.

She says Metro Vancouver is monitoring air quality as smoke has drifted into Vancouver, but it has not issued a general advisory yet.

Highway 17 remains closed from Highway 99 to the Highway 91 connector, and some businesses have been evacuated.

ORIGINAL: 6 a.m.

A fire burning in a suburban Vancouver conservation area has jumped the highway, forcing roads to close and businesses to be evacuated.

The blaze in Burns Bog was first reported around 11:40 a.m. Sunday and gusting winds fuelled its growth throughout the afternoon, said Delta fire chief Dan Copeland.

Delta police issued a statement late Sunday night that said the fire had grown to between 55 and 70 hectares in size, and was expected to take at least a week to extinguish.

The statement added that a Delta firefighter had been hospitalized due to a medical condition aggravated by the environment at the scene of the fire.

Copeland acknowledged that the blaze was giving crews a hard time.

"We were struggling. We had heavy winds this afternoon," he said. "They were a bit unpredictable. They were shifting on us and it was quite a dynamic fire."

Smoke appeared to have drifted into downtown Vancouver by early Monday morning, causing a heavy, acrid smell in the air.

Provincial crews were called in to help early Sunday afternoon. Donna MacPherson with the Coastal Fire Centre said about 26 provincial firefighters, and several airtankers and helicopters were assisting.

Other fire departments in the region, including from Metro Vancouver, also provided backup as the flames spread, eventually jumping Highway 17 and forcing police to evacuate an industrial area.

Delta police chief Neil Dubord said the evacuation was a precautionary measure.

"Certainly everyone is concerned about their businesses, but at this point in time, we don't feel that there's any threat to the businesses," he said.

Police also closed Highway 17 between Highway 99 and the Highway 91 Connector, diverting traffic around the fire, and the Fraser River was temporarily closed to marine traffic so airtankers could scoop water.

Dubord said it was unclear whether the roads would reopen in time for rush hour traffic Monday morning.

There was no indication Sunday evening of what caused the fire, Copeland said.

The fire chief described the blaze as a grass fire, and said embers from large deciduous trees are falling, creating spot fires.

"It's very dangerous," Copeland said. "It's very smoky."

The geography of Burns Bog also presents a challenge for fire crews.

Located southeast of Vancouver, the 30-square-kilometre nature reserve is one of North America's largest peat bogs, and the fire can get under the dry peat where it will burn out of sight.

"If a fire gets underground in that peat, it can run a long way and pop up somewhere else. So it's a very major concern in that regard," said Delta Mayor Lois Jackson.

It's not the first time Jackson has witnessed a major fire in the area. She was mayor in 2005, when a blaze in Burns Bog grew to more than two square kilometres and took more than a week to put out.

The mayor said Sunday that she hasn't had time to think about the previous blaze.

"We're throwing everything we've got at this fire to get it out as soon as we can. Obviously it's a very tricky fire to fight," Jackson said.