Michael Bromwich, head of Interior's Bureau of Ocean Energy Management, said there is no ban on shallow water activity, but it has taken more time to make sure drilling applications meet new standards enacted since the BP oil spill in the Gulf of Mexico in April.

Following the BP drilling accident, the Interior Department enacted more stringent drilling rules, including a requirement that companies certify they have working blowout preventers.

Interior said 13 drilling applications have been submitted since new guidelines were issued on June 8. As of Sept. 10, the department said five applications have been approved and eight are pending.

The department's six-month ban on exploratory drilling is supposed to apply only to water depths more than 500 feet, but drillers have complained that lengthy approval times for new wells have led to a de facto moratorium even in shallow waters.

"I understand the frustration that people feel because we are not able to review and approve applications as expeditiously as we have in the past," Bromwich said in a statement, following a meeting with shallow water drillers.

"But the central fact is that it has taken time to submit and verify the additional required information," he said.

Bromwich said the department would not approve applications until they fully comply with new requirements. "That will not make everyone happy, but it is the right way to proceed," he added.

A coalition of shallow water drillers said they appreciate the concerns about safety, but shallow water development does not pose the same risks as deepwater operations. They called for creation of a tiered review process based the amount of risk associated with different projects.

"BOEM must recognize that it cannot continue to shove a square peg into a round hole by treating all offshore drilling operations the same, disregarding history and geological facts," said Jim Noe, Executive Director of the Shallow Water Energy Security Coalition.

Noe said 15 of the 46 available shallow water rigs have been idled without permits and warned the approval process would need to be speeded up to avoid "economic calamity."