Cleanup continued Tuesday on a major oil spill that has forced residents of a Burnaby, B.C., neighbourhood from at least 50 homes, and raised serious environmental concerns.

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A pipeline was ruptured at Inlet Drive and Ridge Drive in Burnaby, B.C., spilling oil in the neighbourhood. ((CBC))

By late afternoon, the spill, which crept down to the waters of Burrard Inlet, was contained.

But officials were still assessing how much crude oil was spilled, after a construction crew's backhoe inadvertently broke a pipeline that connected a refinery to are fuelling facility in the harbour.

There's controversy over how the spill occurred. The construction crew charges that he pipeline wasn't properly marked, and the pipeline operator has blamed the crew.

The leak was stopped after 30 minutes and the larger, precautionary evacuations of homes west of Inlet Drive, along Ridge, Belcarra, and Malibu drives and North Cliff Crescent were called off.

Some witnesses said oil shot 30 metres into the air like a geyser for 25 minutes. The black liquid rained down on houses, spewed across two lanes of traffic and ran downhill into the inlet.

The residents of the 50 homes that had to be evacuated will be put up at hotels for one to two nights, Burnaby Mayor Derek Corrigan said.

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Witnesses say crude oil shot 30 metres into the air like a geyser for 25 minutes. ((CBC))

"We smelled oil and the smell of gas in [our] home," said one resident, Natalie Marson."Next thing I know, we heard a frantic knock and it was police officers telling us to get out."

Corrigan confirmed to CBC News that a construction crew digging with an excavator on Inlet Drive near the intersection of Barnet Highway and Hastings Street ruptured the pipeline carrying crude oil at around 12:30 p.m local time Tuesday.

The crew said the line, which is operated by Kinder Morgan Canada, was improperly marked.

It's up to the company to mark the location of the oil pipeline before a construction crew starts working, Corrigan said. But the exact cause of the rupture still needs to be determined, he added.

Ian Anderson,president of Kinder Morgan Canada, blamed city contractors for the massive oil spill.

"We will be undertaking a thorough investigation of what occurred. We will be following up with contractors," he said.

Oil pipeline work carefully planned: company head

Anderson said his company was in contact with the contractors to ensure they knew the location of the oil pipeline.

"When we mark these lines, we typically mark the surface where the sewer work is to be done," he said. "We [were]in contact with contractors working in the area last week, planning out the work they're doing."

The Barnet Highway has been closed from Hastings to St. John Street until further notice, causing traffic delays between Vancouver and cities east of Burnaby.

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The oil spread to nearby Burrard Inlet. ((CBC))

Jay Ritchlin, a marine conservation specialist with the David Suzuki Foundation, said it will take a few days to determine whether the marine environment has been harmed.

"Immediate bird kills are an obvious sign, or marine mammals that are stranded and in distress," Ritchlin told CBC News. "You also have to be concerned about the oil residue that settles into the coastline, any of the marshes along on the way there."

Dr. Martin Helina, of the Vancouver Aquarium, said there could be long-term toxic effects on any exposed animals.

"They [toxins] hurt the liver, might infect the lungs, might hurt red blood cells, might affect reproduction many, many years down the line," he said.

BC Transit officials said Tuesday afternoon that at least one bus route to Coquitlam was out of service. The West Coast Express, a commuter rail service linking cities such as Mission, Maple Ridge, Pitt Meadows, Port Moody, Port Coquitlam, and Coquitlam with downtown Vancouver, was running with delays.