The sinkhole in Assumption Parish is quite a bit larger. Natural gas has entered a nearby aquifer from the Texas Brine cavern. Cleanup continues, but it’s dangerous because of the instability of the cavern.
When originally measured in mid-August, the sinkhole near Bayou Corne was 370 feet wide. It’s now grown to 550 feet wide after a series of edge collapses. Cleanup is continuing on the surface of the water in the sinkhole, but no boats are allowed because of the unpredictability of the cavern underneath.
The cause of the sinkhole has been determined by the Louisiana Office of Conservation and their contractor Shaw Environmental and Infrastructure to be a collapse of the west wall of the Texas Brine Company’s cavern. As a result of the collapse, crude oil and natural gas from a naturally-occurring formation was able to reach the surface and contaminate a nearby aquifer.
The collapse likely happened when pressure in the cavern wasn’t high enough. Texas Brine Company is required by the Office of Conservation to monitor the pressure and report on any changes immediately. Texas Brine will also be required to continue to collect data to determine the exact structure of the cavern and how that will affect the surface and subsurface.
Texas Brine Company has started to pump brine into the cavern. This will keep the pressure at a level that will prevent the cavern from collapsing further. At the same time, it will remove the oil and gas from the cavern.
A flyover video from 15 Oct 2012 is below. The trees are no longer visible in the sinkhole. The yellow lines are booms to prevent oil from spreading into the water beyond the sinkhole.