As flames soared above Lac-Mégantic, Que., in the early hours of July 6, the railway company whose train had jumped the tracks and exploded hours earlier made an urgent phone call to Cornwall, Ont.

That’s where the emergency dispatcher for Ottawa-based oil clean-up specialist Eastern Canada Response Corporation (ECRC) is located. Later that day, ECRC was on the scene in Lac-Mégantic, using a complicated array of technologies to remove oil from the Chaudière River, which feeds into the St. Lawrence.

Since then, the company’s booms, vacuums, skimmers, and trucks have removed about 100,000 litres of oil from the Chaudière, according to an estimate by the Quebec environment minister.

The minister has said that in weeks, if not days, the ecological danger to the river will have passed.

But as light crude continues to shimmer on the river’s surface and dead fish slick with oil continue to be pulled ashore, the true size of the spill remains unknown.

That’s because a confidentiality agreement between Montreal, Maine & Atlantic Railway and ECRC prevents the clean-up company from disclosing how much oil and water they have pulled from the river.

Asked whether the company had told them the scope of the oil removal, Jean-Marc Lachance, a regional director in the Quebec environment ministry said, “It’s something we’re working on.”

“We’ll have them one day,” he said of the figures, conceding that the 100,000-litre estimate was “just a guess.”

The train that derailed at Lac-Mégantic comprised 73 tank cars, each capable of carrying almost 100,000 litres of crude. Some of the spilled oil is thought to have burned up in the fire that consumed half of the city’s downtown.

ECRC president Jim Carson confirmed that the company has not shared the quantity of oil removed from the river with any government body.

“I can’t give you that,” said Carson when asked about the amount. “There’s some confidentiality here towards our client.”

Carson explained that under Canadian law, the polluter in an oil spill has to pay for the cleanup. That means that the company responsible for the spill generally hires a company like ECRC and gives them “marching orders.”

Environment Canada and the provincial government have a presence along the Chaudière, but they are there in a “monitoring role,” Carson said.

“They recommend things, but we take our direction from (MMA).”

The environment ministry insists they have some input. “We’re working with them on their methods of cleaning the riverbed,” Lachance said.

But all of the equipment and staff cleaning the river belong to ECRC, Carson noted.

The company is using a range of devices to remove the light crude, from sausage-like “sorbent booms” made of shredded cellulose that soak up the oil; to “mini-vacs” that hoover oil off the water’s surface; to large drums called “skimmers” that spin in deeper sections of the river and bind the oily water to their plastic surface.

The company has also used non-absorbent booms to divert the oil, running with the river’s current, toward the shore, where it’s easier to remove.

The light crude oil spilled by the train sits like a “skin” on the water surface, Carson said. The summer heat has helped evaporate some of it. Heavy crude would have evaporated less and been harder to clean, he said.

A group of citizens calling themselves “Nos cheveux à Mégantic” approached the company about using booms made of human hair in the clean-up, but the company declined.

When the oil is collected, it is trucked to a disposal plant. The company knows how much water and oil they have gathered, but cannot tell for sure how much of the liquid is oil and how much is water.

Keith Stewart, a Greenpeace researcher, said he was “stunned” by ECRC’s silence on the oil removal total.

“By keeping (the government) in the dark, you’re making everyone’s life more difficult … . Why complicate what is already one of the most complicated oil spill cleanups in Canada’s history?”

Carson said he had “no idea” how long the cleanup would take. “I wouldn’t want to give any number because it’s so uncertain,” he said.

The environment ministry says the ecological fallout from the oil spill will be minimal, and short-lived.

“A few dozen (dead) fish along hundreds of kilometers is not a lot,” said Lachance.

He also said that a visual survey of the river’s surface suggests most of the oil is gone or lodged in the riverbed, where it is just a matter of digging it out.

Authorities were also quick to pronounce the lake safe to swim in last week, although residents interviewed by the Star said they still considered the lake dirty and would not swim in it.