Last week, the Coast Guard recovered 4,167 pounds of matted tar that officers believe to be from the 2010 BP oil spill. The vast tar mat was found by crews inspecting the Louisiana coast at Port Fourchon following Tropical Storm Karen, the Times-Picayune reports.

The exact size of the tar mat has not been determined, but Petty Officer 1st Class Michael Anderson told the Times, “We’re expecting a significant amount of product.”

The Coast Guard does not expect that the new mat will be as extensive as the one found earlier this year. In June, shortly after BP ended its cleanup efforts in 3 states, the Coast Guard discovered a 40,000 pound tar mat under the surf off Isle Grand Terre, Louisiana.

Workers have been recovering oil that was buried under little more than a foot of sand, HoumaToday notes.

BP ceased cleanup efforts in Alabama, Florida, and Mississippi this summer, though environmental groups said the decision was premature. “We don’t want the nation to think this disaster is over when oil washes ashore somewhere along Alabama’s 53 miles of beach every day,” Casi Callaway, executive director of Mobile Baykeeper, told CNN.

At the time, the director of the National Wildlife Federation’s Gulf of Mexico Restoration Campaign, David White, said that “As much as one million barrels of oil from the disaster remains unaccounted for, and tar mats and tar balls from the spill continue to wash up on the coast.”

“We cannot just accept oiled material on our beaches and in our marshes as the ‘new normal,’” he added.

Contrary to past incidents, BP does not seem to be contesting that the tar mat is a result of their 2010 disaster.

A BP PLC spokesman, Jason Ryan, said the most-recently uncovered tar mat is located in an “active area,” where authorities “knew the storm might expose residual oil,” according to The Republic. Today, patrolling and maintenance takes place on just 26 miles of Louisiana coastline. Fifty-two additional miles are in “various stages of inspection, periodic monitoring or the approval process,” Ryan said.

During the week following Tropical Storm Karen, cleanup workers found more than 500 pounds of tar balls and nearly 400 pound of oiled debris.

Just last week, researchers at Auburn University released new findings that tar balls “are reservoirs for a multitude of dangerous bacteria, including at least one pathogen that can and has caused life-threatening sickness and death in some humans,” The Locust Fork News-Journal reports.

“What matters is that people be aware that tar balls can be hazardous to their health and that the more tar balls you encounter, the higher the risk,” said Cova Arias, Auburn aquatic biologist and the study’s leader.

As early as months after the spill occurred in April 2010, BP was sponsoring advertising campaigns claiming that Gulf Coast beaches were safe. The newest tar mat surfaced even as BP has been fighting in a federal court in Louisiana, attempting to downplay the damage from their Deepwater Horizon disaster.

Alisha is a writer and researcher with Ring of Fire. Follow her on Twitter @childoftheearth.