Giant Louisiana sinkhole grows to 4 acres

Giant sinkhole grows to 4 acres

By Amber Stegall | October 15, 2012 at 2:03 PM CDT - Updated June 28 at 9:47 AM

Source: Assumption Parish Office of Homeland Security and Emergency Preparedness

Map of the salt dome that is linked to the giant sink hole (Source: Assumption Parish Office of Homeland Security and Emergency Preparedness)

BAYOU CORNE, LA (WAFB) - Issues continue to pile on crews working on the growing sinkhole in Assumption Parish.

Texas Brine, the company that owns a failed salt cavern blamed for the sinkhole says it will comply with new orders.

Texas Brine continues clean up Monday, but is limited to skimming as boats will not be allowed in the sinkhole due to the activity of removing hydrocarbons from the cavern. This is for the safety of workers as the removal of the hydrocarbons may cause pressure changes that could affect the sinkhole.

The current size of the sinkhole is just under four acres.

State officials are ordering further testing along with monitoring and removal of natural gas trapped underground.

Residents are still evacuated; they left their homes in early August.

Below is a summary of the directives that Texas Brine was ordered to perform in DNR's Third Amendment to the Declaration of Emergency & Directives (issued on 10/11/2012).

On or before Tuesday, October 16, 2012:

Texas Brine must provide Dept. of Conservation with a plan for installing and monitoring additional Geoprobe wells to monitor water quality/ pressures in the Bayou Corne community; install & monitor permanent elevation benchmark at each Geoprobe well location by a professional licensed surveyor;
Texas Brine must provide Dept. of Conservation with a plan to install a continuous pressure monitor on Oxy Geismar #3- to monitor pressure and provide for telemetry monitoring of this pressure. This telemetry shall be reported in real time to the Assumption OEP , the Assumption Parish Sheriff's Office, and the Office of Conservation to notify them if any rapid pressure changes that indicate changing conditions in the cavern;

On or before Friday, October 19, 2012:

Texas Brine must provide Dept. of Conservation with a plan to install a permanent continuous water level monitoring station near the edge of the sinkhole. This station shall include a sensor and recording system for monitoring and recording the water levels and a staff gauge for visual observation of water elevation or depth. The data from this station shall be downloaded weekly and forwarded to Dept. of Conservation on a weekly basis;
Texas Brine must provide Dept. of Conservation with a plan to evaluate the alluvial aquifer water production, groundwater flow, sinkhole chlorides, TDS (Total Dissolved Salinity) and hydrocarbon migration and to mitigate adverse impacts to aquifer sustainability from use of Texas Brine Company LLC's water wells;

On or before Thursday, October 25, 2012:

Texas Brine must provide Dept. of Conservation with a plan to implement a seismic monitoring and notification system to allow for real time data processing and interpretation of micro-seismic data. The current array should be expanded as necessary to assess the current stability of the collapse zone. The seismic data shall be reported in real time to the Assumption OEP , the Assumption Parish Sheriff's Office, and the Office of Conservation to notify them of sudden changes in the cavern or surrounding the sinkhole;
Texas Brine must begin installing the groundwater observation/vent well in the vicinity of the core-hole where the ten-feet of gas in the aquifer was observed;

On or before Tuesday, November 13, 2012:

Texas Brine must provide Dept. of Conservation with a plan to collect, interpret, and report geophysical data that will determine the nature and extent of the collapse structure from the base of the original cavern to the ground surface. This geophysical data may include (but not is limited to) vertical seismic profiling, cross-hole seismic and tomography, and 3D seismic.