In his first appearance before lawmakers since the drilling accident 29 days ago, the interior secretary promised to give officials who regulate offshore drilling "more tools, more resources, more independence and greater authority."
When asked whether another rig could have a similar problem, Salazar said that all rigs are inspected every 30 days, according to regulations.
But ABC's Jake Tapper reports that the requried monthly inspections do not always happen.
At the Deepwater Horizon site alone in the past five years, an entire year's worth of inspections did not happen. Of 60 required inspections, only 48 occurred, and that includes four missed inspections out of the 16 required since President Obama's inauguration.
That's evidence to some of a wider problem.
"It's plain that there's a long history here of a lax oversight role by the part of the Minerals Management Service," said Wesley Warren, Director of Programs for the Natural Resources Defense Council.
On Monday, one of the regulators who was charged with monitoring offshore oil programs in the gulf for more than a decade announced he would retire at the end of the month. Chris Oynes, associate administrator for the Minerals Management Service, is the first administration official to resign since the spill.
ABC's Jake Tapper, Ayana Harry, Azfar Deen and The Associated Press contributed to this report.