THE SINKHOLE - THIS IS NOT GOOD

 

Texas Brine Co. LLC suspended cleanup work at a large sinkhole in northern Assumption Parish after the southwestern edge of the slurry area collapsed Thursday morning, company and parish officials said.

Two workers with Texas Brine’s cleanup contractor, Clean Harbors of Norwell, Mass., were rescued from their small aluminum boat by a co-worker in an airboat shortly before the workers’ boat sank into the sinkhole along with the collapsing earth, the officials said.

Assumption Parish Sheriff Mike Waguespack said the boat was tied to a leaning tree on the shoreline. The workers saw the tree begin to move and managed to get out the way, escaping with their equipment at about 8:30 a.m., the officials said.

Waguespack said an area of earth collapsed that extended from the shoreline to about 50 feet inland. The sheriff said bubbling in the sinkhole intensified after the collapse.

Texas Brine and the civil authorities expected the sinkhole to expand, but, despite their reassurances, I wonder about the unexpected that could happen.  I fully understand that the authorities don't wish to alarm people unnecessarily, but still...

In an earlier post on the sinkhole, one of my readers speculated that the butane stored in the salt cavern might be in barrels, but I see no mention of barrels thus far.

Crosstex also submitted a revised worst-case scenario analysis in its risk management plan Wednesday at the request of DEQ Secretary Peggy Hatch.

In a statement Thursday, DEQ officials noted that the cavern, which is a half-mile underground and far below the bottom of the sinkhole, cannot release its liquid butane contents without water being pumped into the cavern to push out the butane. The butane is also being held in the absence of oxygen. (My emphasis)

“While it is easy to simply convert the known quantity of butane into a blast scenario, that does not mean this scenario is possible,” DEQ officials said in a statement.

My inner pessimist which, though buried, occasionally rises and now thinks of oxygen somehow getting into the mix in one of those who-would-ever-have-expected...scenarios.  Surely my inner pessimist is way off base.

UPDATE: My inner pessimist is not the only one concerned.

Assumption Parish Sheriff Mike Waguespack said Thursday he is now concerned the sinkhole is close to a well containing 1.5 million barrels of liquid butane, a highly volatile liquid that turns into a highly flammable vapor upon release. A breach of that well, he said, could be catastrophic.

 

Map from International Business Times.

SINKHOLE, SALT CAVERN, BUTANE UNDER PRESSURE

The Louisiana Department of Environmental Quality has asked the operator of a salt cavern near a sinkhole in northern Assumption Parish to describe what would happen if all butane that could be held in the underground storage facility were released to the surface, state officials said Tuesday.

DEQ Secretary Peggy Hatch asked for the updated worst-case scenario from Crosstex Energy LP of Dallas by close of business Wednesday after reviewing the company’s current risk management plan for the cavern, state officials said in a news release.

The Crosstex salt cavern, which holds 940,000 barrels of liquid butane under pressure, is 1,600 feet from the sinkhole on the adjacent Texas Brine Co. LLC property south of La. 70 south.

DEQ says the Texas Brine is in compliance, but the what-if ramifications if the salt dome has failed are sobering, indeed.

DEQ officials said Tuesday there are “a lot of dynamic things” happening around the butane cavern, including expected well drilling, and community concerns have arisen.
....

DNR scientists suspect the Texas Brine cavern may have been carved too close to the edge of the Napoleonville Dome and failed, releasing its brine contents and causing the sinkhole.
....

DEQ officials said Crosstex’s updated plan submitted in January considers risks for butane, natural gas and other gases and suggests a full release might lead to windows being broken at two-thirds of mile. Piehler said two-thirds of a mile is close to the Bayou Corne community, which has about 150 residences, but does not actually include it.

Jill McMillan, spokeswoman for Crosstex said:

“Based on these findings to date, we believe our facilities have not been impacted by the slurry-filled sinkhole, and there has been no indication their integrity has been compromised,” she said in the email.

Let's hope and pray that none of the worst-case scenarios happen, nor a scenario that none of the experts have thought of, and we hear the lament, "Who would ever have expected...?"  That amount of butane under pressure sounds quite dangerous to me, and I hope the authorities are not playing down the seriousness of the situation as authorities are wont to do.

For those of you who may be concerned about us, we are about 30 miles away from the site and presumably safe.

Thanks to MM for his concern.  I planned to post on the situation yesterday but never got around to it.

TREMORS, BUBBLES IN THE BAYOU, AND A SINKHOLE

 

A 381-foot-deep sinkhole that emerged last week near the Bayou Corne community is filled primarily with salt water mixed with traces of diesel fuel, while the muck and vegetation visible at the surface is only six inches deep, Assumption Parish [Louisiana] officials said Monday.

A nearby 20-million-barrel Texas Brine Co. LLC of Houston salt cavern, which was plugged in 2011, was filled with brine, a water-salt mixture, for structural integrity, company officials have said.

Some closed salt caverns also have diesel fuel at the top as a “pad” to prevent erosion of the salt from the brine, said John Boudreaux, director of the Assumption Parish Office of Homeland Security and Emergency Preparedness.

The disclosures Monday may further point to Louisiana Department of Natural Resources officials’ suggestions Friday that the sinkhole, which has a diameter of 372 feet, was caused by the possibly failed cavern.

“It’s suspect,” Boudreaux said.

In an earlier story in the Baton Rouge Advocate, people who lived in the area of Bayou Corne reported  tremors and gas bubbles in the bayou, as in the photo above.  You may or may not know that earthquakes are extremely rare occurrences in Louisiana.  Gas bubbling up in a Louisiana bayou is also an unusual event.  So what's going on?

Assumption Parish emergency officials have asked to meet with an expert from the U.S. Geological Survey and for portable seismic equipment to get a better understanding of new tremors reported in the Bayou Corne and Grand Bayou areas, officials said Friday.

The earth tremors are being reported by residents in a swampy area of northern Assumption Parish where venting streams of natural gas have been roiling the surface of waterways for about a month.

The source of the natural gas remains uncertain and is not an explosive risk but detailed tests to fingerprint the source of the leaking gas are pending, said John Boudreaux, director of the parish Office of Homeland Security and Emergency Preparedness.

The word from the state at that time was that tests show the gas was not explosive, and no connection has been made between the tremors and the gas bubbles.
  

Then comes the sinkhole. Who would ever have expected...?  But wait! Maybe the sinkhole should not have been so much so much of a surprise to state officials.  

In a Jan. 21, 2011, letter, Mark J. Cartwright, Texas Brine Co. Saltville LLC president, informed DNR about a failed integrity test of the cavern and company officials’ subsequent suspicion that the cavern may have breached the Napoleonville Dome’s outer wall, possibly explaining a loss of pressure in the cavern during the test. (Read letter.)

“One obvious concern is the cavern’s proximity to the edge of salt,” Cartwright wrote to DNR’s Joseph “Joe” S. Ball Jr. “There have been several studies in this regard, and Texas Brine has mapped the salt boundary near the cavern applying available well log data, seismic data, and most recently, vertical seismic data gathered during the workover. At this time, a breach out of the salt dome appears possible.”

Ball is the director of the DNR Injection and Mining Division, which oversees salt caverns.

Neither parish officials nor the public was informed that the integrity of the salt cavern may have been compromised.  Over 300 people have been evacuated from their homes, and more may have to go.  In addition to concerns about natural gas and diesel leaks, we learn that some years ago, Texas Brine was allowed to pump radioactive waste into the cavern which may now be leaking.

As I read the Advocate story linked at the beginning of the post yesterday morning, I noted another story on the same page of the announcement by the governor's office that Scott Angelle, Secretary of the Department of Natural Resources, resigned, no reason given.  We could maybe take a guess as to the reason.

I've been trying to post about the story since there was only one report, but I have not had time.  Now I have four links expanding the story, and I could probably find more.  The story grows and grows, and the situation looks grimmer and grimmer.

Question: If we extract large amounts of materials from beneath the ground, why are we surprised, when the ground collapses?