5:15 p.m. Update from the Office of Conservation

Bayou Corne/Grand Bayou Response Activity

Following confirmation of the new bubble site on Grand Bayou, north of its crossing of La. 70, Assumption Parish Incident Command and the coordinated state agencies have made initial investigations and begun taking action to ascertain the source, including determination of whether scientific evidence supports the likely assumption that it is linked to the gas released by the failure of Texas Brine’s Oxy Geismar 3 cavern, and to ensure public safety.

The bubbling is occurring directly above the area where Acadian Gas recently drilled a horizontal boring under the Bayou as part of its effort to re-route a pipeline to replace pipeline capacity lost when the sinkhole formed. Acadian has already tested its two existing pipelines in service at the same crossing, and found no indication of leaks.
The Office of Conservation and its contracted agent CB&I have taken gas samples at the bubble site to “fingerprint” the gas and help in determining its origin.
DEQ has added the new site to its community air monitoring protocol, and DOTD will include the nearby roadway in its monitoring program for potential road deterioration.

Tuesday, Feb. 25 work-
Sinkhole Activity Code 1 – indicating work is allowed on sinkhole and within containment berms. Seismic monitoring indicates continued low levels of subsurface activity near sinkhole/Oxy 3.

Air Monitoring/Sub-slab Sampling and Ventilation
– Conducting ventilation system inspections

– Continuing ORW 21 pump test (north of Sauce Piquante, west of Crawfish Stew)
– Conducting pump test on ORW 16 (west of containment berm) in preparation for de-watering

Containment Berm/Roads/Sinkhole
– Surveying north containment berm and original south containment berm
– Conductinig geotechnical borings near new south containment berm route
– Preparing new driveway area at 1439 La 70 (south of La 70) and placing limestone
– Installing turbidity curtain along Bayou Corne side of new south containment berm
– Collecting sinkhole in-flow water samples
– Monitoring industrial water wells
– Conducting water sampling of aquifer