NEW ORLEANS — Highly anticipated and controversial cleanup operations will begin this week at a 15-year-long oil leak in the Gulf of Mexico, the U.S. Coast Guard confirmed Wednesday.

A Taylor Energy oil and gas production platform that toppled in a mudslide during Hurricane Ivan in September 2004 has been leaking ever since, about 10 miles from the mouth of the Mississippi River.

The Coast Guard issued a waterway restriction on vessels, forbidding anyone from getting within 500 yards of the supply vessels Ocean Patriot and Ross Candies while they are at the leak site, carrying and deploying the oil spill containment equipment. As of early Wednesday afternoon, both vessels were in Port Fourchon, according to the vessel tracking website MarineTraffic.com. That's about 75 miles from the spill site.

The Federal Aviation Administration also issued a restriction, forbidding any aircraft from flying less than 1,500 feet above the leak site starting Wednesday and on through March 15.

“Containment installation operations are anticipated to begin later this week and continue into March,” Coast Guard Chief Petty Officer Lauren Jorgensen said in response to questions from WWL-TV. “Due to the dangerous lifting and hoisting of extremely heavy equipment from the deck of a rocking vessel, the temporary flight restriction and the safety zone will ensure safety of response personnel by eliminating unexpected distractions overhead and on the surface.”

New Orleans-based Taylor stopped all its oil and gas operations in 2008 and has existed since then solely to deal with the 2004 leak. Taylor drilled so-called intervention wells to intercept and plug nine of the 25 wells that had been connected to its downed platform. Those were the nine wells it determined could be leaking. In consultation with the Coast Guard and hired scientists, Taylor determined the other 16 wells that had been connected to the platform were dry.

But the slow leak continued to leave a sheen on the water’s surface every day. Taylor claimed it was coming from oil that had already escaped from its wells and was trapped under a 100-foot pit of mud on the seafloor.

Taylor and the Coast Guard worked together under what’s called a Unified Command for spill response. They agreed that the leak was minor and conditions on the seabed were precarious. They tried to use containment domes, boxlike structures lowered 450 feet under the water to trap oil at the source of the leak and funnel it into a collection system. But that failed because the mushy sediment from the 2004 mudslide clogged the devices.

But in recent months, the federal government has totally changed its position on the spill, prompted by a series of scientific surveys that found there is still at least one actively leaking well and estimating the amount of oil is potentially 1,000 times larger than what Taylor had estimated.

One report the U.S. Interior Department cited in a lawsuit against Taylor put the rate of the spill at 10,000 to 30,000 gallons of oil leaking into the Gulf every day, a far cry from the 10-gallon-a-day rate offered by Taylor’s hired scientists and previously accepted by the Coast Guard.

Other, independent experts have come up with more moderate estimates of how much oil is leaking. Ian MacDonald, an oceanography professor at Florida State University, was instrumental in correcting BP's vast under-reporting of the size of its massive oil spill in 2010 and has consistently found oil companies underestimating their spills, but he estimates the Taylor spill rate is about 4,200 gallons a day.

He has warned that the spill could have significant environmental impacts and testified as an expert witness for environmental groups when they sued Taylor in 2012. But at the same time, he expressed concern about the uncertainty surrounding this spill.

"Experience shows that controlling the (Taylor) oil spill is very difficult," MacDonald told WWL-TV. "Over $200 million has been spent by Taylor trying to stop it, but the oil is still flowing. I'm concerned that we lack a complete scientific picture of how the oil is being released and what its impact is. Previous attempts at containment domes have failed, (so) I guess we just have to hope that the this time around the dome will hold."

In October, the Coast Guard’s federal on-scene coordinator, Capt. Kristi Luttrell, ordered Taylor to construct new, larger containment domes and deploy them quickly. Taylor offered a proposal that Luttrell rejected. In November, Luttrell seized partial control of the response operations and hired Belle Chasse-based Couvillion Group to construct the new containment devices, at Taylor’s expense.

Taylor complained that the Couvillion proposal could cost it $1 billion, about twice as much as the company has spent over the entire 15 years on spill response. It tried to fight back with negotiations and lawsuits, but that was met with disdain from the Coast Guard.

“I now find that your attempts to engage in further negotiations with Couvillion Group as to contracting terms and pricing … only serves to delay containment activity and could compromise the proposed operations of Couvillion Group, which I have determined is best suited to perform the removal operations,” Luttrell wrote in a Nov. 16 notice to Taylor.

Taylor has also sued Couvillion Group to try to stop it from going on its lease site. Taylor’s president, Will Pecue, says any new efforts on the sea floor or new drilling operations could release a lot more oil and cause more damage to the environment.

But others have raised doubts. David Pritchard, a consultant for global oil and gas companies who studied the causes and impacts of the BP disaster, said Taylor should be drilling intervention wells to plug the remaining 16 wells, rather than suing the government to get back $435 million set aside in a trust for that purpose.

"They just did not want to spend the money," Pritchard told WWL-TV. "It would be very expensive. They know the bottom hole locations of each and every well within reason and the technology exists to find the precise ... source.”

WWL-TV reporter David Hammer can be reached at dhammer@wwltv.com; Follow him on Twitter at @DavidHammerWWL