A huge sinkhole in southern Louisiana that has already forced hundreds of residents out of their homes continues to expand and buck local efforts to prevent it from contaminating other areas. The Bayou Corne sinkhole, a 15-acre-wide hole that opened up last year in rural Assumption Parish, swallowed a berm on Tuesday that was intended to stave off contamination.

The sinkhole, which first gained attention in 2012, hasn't received much notice beyond local Louisiana newspapers, but some concerned environmentalists have dubbed it an “unprecedented environmental disaster.” As of December, io9 reported that cleanup efforts had failed to prevent pollutants in the sinkhole from spreading to nearby waterways. And the sinkhole has only continued to be plagued by problems.

According to OpEdNews.com, residents of Assumption Parish first became concerned last spring when they noticed unusual bubbling in the Grand Bayou. They also reported that the water smelled of fuel and sulfur. Months later a sinkhole “the size of three football fields” appeared, eventually forcing some 150 families to pack up their belongings and evacuate. Almost a year since its sudden appearance, the sinkhole now measures roughly 15 acres.

The Louisiana Office of Conservation recently ordered Texas Brine, the company that owns the abandoned underground salt dome that likely caused the disaster, to install a berm in the sinkhole so that brine rising from the bottom of the sinkhole would not contaminate bordering swamps. However, much of that berm was also swallowed up by the hole earlier this week following a cave-in on the sinkhole’s south side. The Assumption Parish Police Jury, the town's governing body, reported that on Tuesday that 400 to 500 feet of the berm had sunk underwater. They wrote in a report that, "the depth to the top of the berm is 3'9" at it's deepest point. Also, the trees on the Southwest side are showing signs of sinking, some up to 10' in depth [sic]."

Residents who were forced to evacuate have been receiving weekly checks from Texas Brine, the Associated Press reported. The company, which describes itself as the country’s largest independent brine producer, recently offered to buy out some of those residents.

The sinkhole has prompted many worried residents and environmentalists to share news of the disaster on Twitter as well as a community Facebook page and blog site. Many concerned parties have singled out Texas Brine for not taking responsibility for the sinkhole sooner, and for not doing more to prevent it from affecting the surrounding land. According to the Advocate of Baton Rouge, environmental activist Erin Brockovich is involved in the case and has urged residents to take legal action. Lawyers working with Brockovich filed a class action suit on behalf of 57 individual plaintiffs and three local businesses.

View video of a flyover of the sinkhole below.