The Canada-Nova Scotia Offshore Petroleum Board has authorized a Shell Canada Ltd. drilling plan in the Shelburne Basin that allows the company between 12 and 13 days to contain subsea blowouts, but one environmental group is concerned the capping stack won't be housed here.

The timeframe is shorter than the original 21-day plan, but still falls short of the U.S. requirement of 24 hours for drilling in the waters off Alaska.

Shell Canada would also have to deploy a second capping stack as a contingency plan.

In the environmental assessment for the project, Shell Canada said the capping stack equipment would be brought in from Stavanger, Norway. Shell said it would also deploy a backup stack from Brazil.

Stuart Pinks, the CEO of the Canada-Nova Scotia Offshore Petroleum Board, said the original timeline seemed too long.

"We looked at it and said, 'You know, 21 days seems like a long time,'" he said Tuesday.

Environmental concerns

The Ecology Action Centre is calling the shorter timeline an improvement, but it would like to see the capping technology housed in Atlantic Canada.

"If we want an offshore oil and gas industry, then we should be willing — or the company should be willing — to pay for the technology in place for any kind of emergency," said policy director Mark Butler.

He says there is no guarantee Shell would be able to get the capping stack to Nova Scotia within the approved timelines.

"The best way to minimize the time is to have that technology here in Atlantic Canada, so it's one to two days, or 24 hours to get that technology out to the site," said Butler.

Pinks said with a limited number of capping stacks available in the world, it isn't feasible to have one close to every drilling site.

The board said in a news release it is confident Shell Canada will take "all reasonable precautions" to protect the environment and work safely while drilling.

'Unexplored geological region'

Shell Canada's original plan came under fire from critics who felt the 21-day window to contain subsea blowouts was too long.

An online petition by an international environmental group opposing Shell's application to drill off Nova Scotia has collected more than 232,000 signatures.

Disaster

An explosion at British Petroleum's Deepwater Horizon offshore rig in the Gulf of Mexico on April 20, 2010, killed 11 workers. The Canada-Nova Scotia Offshore Petroleum Board has shortened the timeline that Shell Canada must bring in a capping stack in the event of a subsea blowout during its drilling off the coast of Nova Scotia. (U.S. Coast Guard/Associated Press)

The Canada-Nova Scotia Offshore Petroleum Board says regulations around the world say capping stack gear should be available on site within 10 to 30 days.

Earlier this year, Shell Canada submitted applications for a deep-water drilling program 250 kilometres off the coast of Nova Scotia.

The drilling will run for about 10 months in water more than 2,000 metres deep. In a statement, Shell called the Shelburne Basin an "unexplored geological region."

When could drilling start?

The first phase of the program involves drilling two exploratory wells: Cheshire and Monterey Jack.

On Tuesday afternoon, Pinks said the board had given Shell Canada the go-ahead to drill the Cheshire well, which means the company could start drilling as soon as Wednesday. Approval for drilling at Monterey Jack will be required at a later date.

The drill ship required for the exploratory drilling — the Stena IceMAX — arrived in Nova Scotia on Monday and is capable of drilling in water depths of up to 3,000 metres.

Shell says about half of the IceMAX's crew is Canadian, and half of the Canadians are Nova Scotians.

Beginning this year, Shell has a four-year window to drill exploratory wells off the coast.

In 2013, Shell pegged the project's total price tag at $970 million.