Numerous groups alleged that Shell's permits granted by the Environmental Protection Agency would allow the company to emit tons of pollutants into the Arctic environment from a drill ship and support vessels.
The federal Environmental Appeals Board reviewed the permits and last week found that the EPA's analysis of the impact of nitrogen dioxide emissions from the ships on Alaska Native communities was too limited.
The board remanded the permits so that the analysis could be fixed by the EPA.
The Board also concluded that the EPA erred in determining when to count the Frontier Discoverer drillship as a pollutant source.
The Board denied the petitioners' request to review whether the best available emissions control technology was being applied to support ships.
The groups which fought Shell were the Center for Biological Diversity, Earthjustice (on behalf of several conservation groups), and the Alaska Eskimo Whaling Commission and Inupiat Community of the Arctic Slope.
Shell spokesman Curtis Smith said without the permits the company can't proceed with its drilling plans in 2011.
For more info:
Shell Beaufort Sea Program Update September 2010