Shell applies to revise air permits

Shell has applied to the Environmental Protection Agency for revisions to its air permits for the drilling vessel Noble Discoverer and the floating drilling platform the Kulluk. The requested revisions come as a result of recent testing of engines on the vessels.

The Kulluk revisions are minor in nature — Shell will be allowed to implement the changes, although EPA has a 90-day review period in which to take any action, EPA said in a July 11 news release.

EPA is currently reviewing Shell’s proposed changes to the Noble Discoverer permit, which is a major prevention of significant deterioration permit. Any revision to the permit would require public review, the agency says.

In a July 11 email Shell spokesman Curtis Smith said that Shell does not expect the revision requests to impact the company’s 2012 drilling program.

“We are working with the EPA to achieve a compliance order that would allow the Discoverer to operate in 2012 while putting in motion a review process for these issues in 2013 and beyond,” Smith said.

Smith said the Noble Discoverer generator engines had tested slightly above the permit levels for ammonia and nitrous oxide, but that the overall nitrogen oxide emissions for the vessel still meet ambient nitrogen oxide standards.

—Alan Bailey