U.S. officials formally declared an end to the worst oil spill in U.S. history Sunday, a milestone that followed nearly five months of dashed hopes and blistering criticism of nearly everyone involved.

Well owner BP began final cementing operations to permanently plug the blowout on Friday. Pressure tests conducted early Sunday confirmed the cement was holding, and the Interior Department agency that regulates offshore drilling pronounced the well dead at 5:54 a.m. (6:54 a.m. ET), former Coast Guard Adm. Thad Allen said in a statement issued Sunday morning.

“With this development, which has been confirmed by the Department of the Interior’s Bureau of Ocean Energy Management, we can finally announce that the Macondo 252 well is effectively dead,” Allen, the federal government’s point man on the disaster, said in the statement.

The disaster saw oil patch jargon like “junk shot,” “static kill” and “blowout preventer” join the American lexicon, triggered shakeups in government and industry, and left residents of the Gulf Coast frustrated and worried for their livelihoods.

The disaster began with an April 20 explosion aboard the oil rig Deepwater Horizon, about 40 miles off the coast of Louisiana. The blast claimed the lives of 11 workers aboard the platform, which sank two days later in nearly a mile of water.

The rig’s blowout preventer, a massive fail-safe device at the seabed, failed to operate after the blast. Efforts to activate it using remote submarines failed. An effort to plug it with heavy drilling fluid and cement failed. A bid to jam it shut by pumping it full of debris also failed.

The well spewed an estimated 4.9 million barrels (206 million gallons) of crude into the Gulf of Mexico before it was temporarily capped July 15. It was permanently sealed only when BP drilled a separate relief well into the sea floor, intercepting the original well and allowing workers to fill it with cement from below.

The spill struck hard at some of the pillars of the Gulf Coast’s economy as oil washed up on beaches in Louisiana, Mississippi, Alabama and Florida, federal and state authorities shut down Gulf fisheries, and a temporary federal ban on deepwater drilling idled oil workers. More than a third of the Gulf was closed to fishing at the height of the disaster, and tourists stayed away from the region’s white sands in droves.

At the White House, President Barack Obama hailed the “final termination” of the well but said the federal government will continue to do “everything possible to make sure the Gulf Coast recovers fully from this disaster.”

Have you checked out YWN Radio yet? Click HERE to listen!

(Source: CNN)