ANCHORAGE, Alaska – Royal Dutch Shell has received permission to operate its drill ship in the Chukchi Sea under a temporary revision to its air permit, clearing another hurdle in its quest to drill exploratory wells in the Arctic Ocean this year.

A spokesman for the Environmental Protection Agency tells The Associated Press that it will issue a one-year air permit compliance order for Shell’s activities in the Chukchi off Alaska’s northwest coast.

“The order sets interim air pollution emissions limits for the company’s activities, and ensures that Shell’s operations will meet congressionally mandated air quality standards under the Clean Air Act until the agency completes a full review of Shell’s application to revise the permit,” spokesman David Bloomgren said.

The decision is more good news for Shell, which on Thursday received permission to begin preliminary excavation work on Chukchi wells as long as it does not dig into petroleum zones.

Shell Alaska spokesman Curtis Smith said the company applied for the compliance order after determining the air standards could not be attained on its drill ship, the Noble Discoverer, using the best current control technology.

He praised the EPA for making a “reasonable” decision.

“It’s an essential piece for us getting to work in the Chukchi,” Smith said.