So far, so good. The worst oil spill in U.S. history remains capped for a second day, as the well integrity test continued, USA Today reported.
Oil stopped flowing Thursday with the new 75-ton cap atop the site of the Deepwater Horizon well in the Gulf of Mexico.
Engineers with BP closed valves on the cap Thursday afternoon, and for the first time since April oil stopped pouring from the well.
BP now will watch pressure readings to look for signs that any new leaks may develop.
However, the best hope for permanently ending the leak comes from two relief wells that will plug it with mud and cement, as early as the end of July.
Since the Deepwater Horizon rig exploded April 20, the U.S. government estimates that between 90.4 million and 178.6 million gallons of oil have spewed into the Gulf of Mexico.