Proposals are zipping through the Louisiana Legislature to help residents who live near salt domes that are integral to the oil and gas industry.

Salt domes are natural formations prevalent along the Gulf Coast. Companies mine into the domes to extract brine that is piped to petrochemical companies. They also create caverns for the storage of natural gas, crude oil and other materials.

The state Department of Natural Resources has an online map showing the locations of domes and whether they are abandoned or active and whether they are producing brine or storing materials. The domes dip down as far as Clovelly Dome Storage Terminal, near Galliano, and as far north as the Arcadia Dome, between Grambling and Minden.

Scientists believe a company mined too close to the outer face of a dome near the Bayou Corne and Grand Bayou communities last year, causing a sidewall collapse that triggered tremors, created a 13-acre sinkhole and released gas and crude oil.

The collapse occurred at a depth of more than 5,000 feet and resulted in a months-long standing mandatory evacuation of 150 residences.

State Rep. Karen St. Germain, D-Pierre Part, told the Louisiana House Thursday that few residents realized what was happening on nearby property controlled by Texas Brine Co. LLC of Houston. They did not know when they bought their residences that their neighborhood was home to solution-mining injection wells, she said.

Now, St. Germain said, the homeowners live in limbo.

St. Germain filed legislation that would ensure homebuyers are warned about natural gas caverns near their new property. House Bill 494 would require the location of cavities and solution-mining injection wells to be part of property disclosure documents.

She also filed House Bill 493, which would require companies to report setback distances for new caverns from the edge of salt stocks, well inactivity and stability updates. The legislation is aimed at ensuring the state has a good handle on the operations.

Both bills breezed through the House with St. Germain keeping her remarks short.

“I promise not to take much of your time. I think there’s a lot of you that already know what my area’s been going through,” she said.

A day earlier, state Sen. Fred Mills sat down before the Senate Natural Resources Committee to talk about the salt domes underneath state lakes.

Mills, R-St. Martinville, filed Senate Bill 200 to nix storage expansion in the salt domes that have experienced structural failures.

On the face of it, his legislation would affect half a dozen salt domes. But the bill really targets just one: the Jefferson Island salt dome at Iberia Parish’s Lake Peigneur.

A drilling rig pushed through the top of the salt mine in 1980, opening a hole that drained the entire water body.

Decades later, a group called Save Lake Peigneur continues to monitor oil and gas activity at the site. Save Lake Peigneur claims to represent the concerns of 4,000 residents.

The latest battle is over expansion of a natural gas storage operation under the lake.

Save Lake Peigneur, the Louisiana Environmental Action Network and lake-area resident Roger Stelly filed suit. Mills filed legislation.

He and the oil-and-gas industry bickered Wednesday on the reach of his bill. Finally, Mills agreed to limit his ban on storage expansion to salt domes with manmade-caused structural failures — instead of extending it to problems caused by Mother Nature.

“I’m more than happy to take out natural because at Lake Peigneur, it was manmade,” he said.

Michelle Millhollon covers the Louisiana Legislature for The Advocate’s Capitol news bureau. Her email at the mmillhollon@theadvocate.