By Mike Ludwig / TruthOut

For residents in Assumption Parish, the boiling, gas-belching bayou, with its expanding toxic sinkhole and quaking earth is no longer a mystery; but there is little comfort in knowing the source of the little-known event that has forced them out of their homes.

Located about 45 miles south of Baton Rouge, Assumption Parish carries all the charms and curses of southern Louisiana. Networks of bayous, dotted with trees heavy with Spanish moss, connect with the Mississippi River as it slowly ambles toward the Gulf of Mexico. Fishermen and farmers make their homes there, and so does the oil and gas industry, which has woven its own network of wells, pipelines and processing facilities across the lowland landscape.

The first sign of the oncoming disaster was the mysterious appearance of bubbles in the bayous in the spring of 2012. For months the residents of a rural community in Assumption Parish wondered why the waters seemed to be boiling in certain spots as they navigated the bayous in their fishing boats.

Then came the earthquakes. The quakes were relatively small, but some residents reported that their houses shifted in position, and the tremors shook a community already desperate for answers. State officials launched an investigation into the earthquakes and bubbling bayous in response to public outcry, but the officials figured the bubbles were caused by a single source of natural gas, such as a pipeline leak. They were wrong.

On a summer night in early August, the earth below the Bayou Corne, located near a small residential community in Assumption, simply opened up and gave way. Several acres of swamp forest were swallowed up and replaced with a gaping sinkhole that filled itself with water, underground brines, oil and natural gas from deep below the surface. Since then, the massive sinkhole at Bayou Corne has grown to 8 acres in size.

On August 3, Louisiana Gov. Bobby Jindal declared a statewide emergency, and local officials in Assumption ordered the mandatory evacuation of about 300 residents of more than 150 homes located about a half-mile from the sinkhole. Four months later, officials continue to tell residents that they do not know when they will be able to return home. A few have chosen to ignore the order and have stayed in their homes, but the neighborhood is now quiet and nearly vacant. Across the road from the residential community, a parking lot near a small boat launch ramp has been converted to a command post for state police and emergency responders.

“This place is no longer fit for human habitation, and will forever be,” shouted one frustrated evacuee at a recent community meeting in Assumption.

The Bayou Corne sinkhole is an unprecedented environmental disaster. Geologists say they have never dealt with anything quite like it before, but the sinkhole has made few headlines beyond the local media. No news may be good news for Texas Brine, a Houston-based drilling and storage firm that for years milked an underground salt cavern on the edge of large salt formation deep below the sinkhole area. From oil and gas drilling, to making chloride and other chemicals needed for plastics and chemical processing, the salty brine produced by such wells is the lifeblood of the petrochemical industry.

Geologists and state officials now believe that Texas Brine’s production cavern below Bayou Corne collapsed from the side and filled with rock, oil and gas from deposits around the salt formation. The pressure in the cavern was too great and caused a “frack out.” Like Mother Nature’s own version of the controversial oil and gas drilling technique known as “fracking,” brine and other liquids were forced vertically out of the salt cavern, fracturing rock toward the surface and causing the ground to give way.

“In the oil field, you’ve heard of hydraulic fracturing; that’s what they’re using to develop gas and oil wells around the country …”What is a frack-out is, is when you get the pressure too high and instead of fracturing where you want, it fractures all the way to the surface,” said Gary Hecox, a geologist with the Shaw Environmental Group, at a recent community meeting in Assumption Parish. Texas Brine brought in the Shaw group to help mitigate the sinkhole.

As the weeks went by, officials determined the unstable salt cavern was to blame for the mysterious tremors and bubbling bayous. Texas Brine publically claimed the failure of the cavern was caused by seismic activity and refused to take responsibility for the sinkhole, but the United States Geological Survey (USGS) has since determined that the collapsing cavern caused the tremors felt in the neighborhood, not the other way around.

According to Hecox and the USGS, the collapsing cavern shifted and weakened underground rock formations, causing the earthquakes and allowing natural gas and oil to migrate upward and contaminate the local groundwater aquifer. Gas continues to force its way up, and now a layer of gas sits on top of the aquifer and leaches through the ground into the bayous, causing the water to bubble up in several spots. Gas moves much faster through water than oil, which explains why the bubbles have not been accompanied by a familiar sheen.

Documents obtained by the Baton Rouge newspaper, The Advocate, revealed that in 2011, Texas Brine sent a letter to the Louisiana Department of Natural Resources (DNR) to alert its director, Joseph Ball, that the cavern had failed a “mechanical integrity test” and would be capped and shut down. The DNR received the letter but did not require any additional monitoring of the well’s integrity.

Despite this letter, regulators apparently did not suspect the brine cavern to be the source of the bubbles until a few days before the sinkhole appeared, The Advocate reported. The letter raised ire among local officials, who did not hear about the failed integrity test until after Bayou Corne became a slurry pit.

Texas Brine spokesmen Sonny Cranch told Truthout the company has not officially taken responsibility for the sinkhole disaster, but has “acknowledged that there is a relationship” between the collapsed cavern and the sinkhole.

Read more from TruthOut: http://truth-out.org/news/item/13136-bayou-frack-out-the-massive-oil-and-gas-disaster-youve-never-heard-of