Louisiana lawmakers are meeting with state Department of Natural Resources officials, Texas Brine officials and others Monday, a day after another burp and edge collapse at the gradually growing sinkhole in northern Assumption Parish.
The burp and slough-in followed a period of increased seismic activity last week, parish officials said in a blog post.
The slough-in, or edge collapse, happened in swamps just west of a pipeline corridor that at one time formed part of the once-smaller sinkhole’s far western edge.
The sinkhole is believed to have been caused by the failure of a Texas Brine Co. LLC cavern in the Napoleonville Dome. Residents of the Bayou Corne and Grand Bayou communities near the sinkhole have been evacuated more than seven months.
The joint meeting of the state House and Senate Natural Resources and Environment committees was announced last week.
The burp was recorded shortly after 3 a.m. Sunday, surfacing oily hydrocarbons and debris from the 140-foot-deep sinkhole, which has had widely varying depths since it first emerged, parish officials said.
Parish officials noted that a similar period of an increased number of tremors preceded a belch on Jan. 19. The tremors and belch led to the closure of the failed cavern’s surface well pad after it began cracking and part of it sank about six inches.
Parish officials reported that DNR’s Office of Conservation’s contracted experts noted the deep tremors around the sinkhole and the failed cavern have subsided considerably since last week.
But shallow tremors remain, these experts said, probably indicating the sides of the sinkhole falling in and water movement in the sinkhole and below it.
Parish officials reported that the sinkhole continues to be monitored.
“And (the Office of) Conservation will advise the public of significant changes in subsurface conditions,” parish officials reported on the blog post.
State Office of Conservation officials, Texas Brine officials and experts have said the sinkhole is gradually finding a stable size and shape as the failed salt dome cavern, which had a sidewall collapse deep underground, fills with rock flowing in from outside the cavern.