Rain reveals gas bubbles

Advocate staff photo by ADAM LAU -- One of a few, small bubble sites percolates up through floodwaters inundating a formerly dry patch of swamp off Crawfish Stew Street in Bayou Corne on Friday.  Methane gas is trapped under the Bayou Corne area, leading to gas seeps in area waterways, in a nearby sinkhole and around water wells. These much smaller sites are situated on normally dry land, sites now revealed only after flooding from recent rains. Show caption
Advocate staff photo by ADAM LAU -- One of a few, small bubble sites percolates up through floodwaters inundating a formerly dry patch of swamp off Crawfish Stew Street in Bayou Corne on Friday. Methane gas is trapped under the Bayou Corne area, leading to gas seeps in area waterways, in a nearby sinkhole and around water wells. These much smaller sites are situated on normally dry land, sites now revealed only after flooding from recent rains.

High water from recent heavy rains revealed small sources of natural gas venting in the Bayou Corne community, a swampland settlement that has been evacuated for more than five months since the formation nearby of a large sinkhole, residents and officials said.

The high water inundated a formerly dry patch of wooded swampland across Crawfish Stew Street from a handful of homes in a neighborhood north of La. 70 South, residents said.

Nick Romero, 64, said Friday he noticed the bubbles sometime last week after the high water came in and thinks more bubble sites emerged since then in the woods.

“I’m seeing more little spots,” he said, looking out at the woods across Crawfish Stew from his house.

The failure of a Texas Brine Co. LLC salt cavern is believed to have caused the 8.5-acre sinkhole south of the neighborhood, released crude oil and allowed methane gas to enter the shallow aquifer underlying the community.

The underground gas, amounting to an estimated 50 million to 100 million cubic feet, previously has been identified as spawning bubble sites in area bayous, from the sinkhole and from sites around land-based water wells.

But a variety of community air monitors, an aerial overflight this summer and in-home testing have not found methane coming from land or in homes, officials have said.

Bubbles could be seen Friday in shallow water left by the storms this month. Bubbles also appeared sporadically in spots in the wooded swamp. The most consistent bubble site, though still small, was near a metal stake driven in the ground for a utility pole guy wire.

Bubbles could also be seen, though less active, in a puddle around another guy wire stake a few just down from Romero’s house.

Romero said he is concerned what the bubble sites might mean in regard to how close the underground gas is to the surface of the ground.

“To me, I’m thinking the gas is closer to the surface than they think,” Romero said.

John Boudreaux, parish Office of Homeland Security and Emergency Preparedness director, said Friday the bubble sites have been tested, but they were not emitting enough gas to be detected by the instruments.

Boudreaux said the bubbles near Romero’s house are closer to homes than almost any of the other bubble sites and that is a concern.

Scientists working for the Louisiana Office of Conservation fear that the methane, a colorless, odorless gas that can explode at high-enough concentrations, could accumulate in homes, leading the state agency to order Texas Brine to install in-home monitor devices and wells to burn off the gas.

That fear also reinforced the need for the parish’s standing evacuation order issued Aug. 3. The parish has not required residents to leave, and some have remained behind, such as Romero.

Patrick Courreges, spokesman for the Louisiana Department of Natural Resources, said in a statement Friday that the guy-wire stake is driven several feet into the ground and had become a likely conduit allowing shallow natural gas to reach the surface.

Several weeks ago, contractors working on the sinkhole response attempted to install an elevation benchmark in the same area.

Piping driven into the ground to support the benchmark needed to measure elevations in the area released gas that could not be controlled, so the benchmark had to be removed to permit the hole to be filled with cement to stop the gas flow.

Courreges pointed out that Shaw Environmental and Infrastructure Inc. scientists working for the Office of Conservation have previously noted that natural gas in the aquifer “could push methane in low concentrations into near-surface soils.”

He said Conservation and Shaw officials are continuing “to analyze the situation as part of the ongoing response effort to ensure public safety and return the Bayou Corne community to normal.”

Some took the discovery of the latest bubble sites as a sign of an inadequate response by state officials and called for federal intervention.

Nara Crowley, president of Save Lake Peigneur, distributed an email this week about the new bubbles and asked residents to sign an online petition to the White House calling for a federal emergency declaration.

“This entire situation is a travesty. The people who suffer the most consequences are the residents,” Crowley wrote.

Her advocacy group opposes the expansion of a salt dome storage facility at Lake Peigneur in Iberia Parish but has gotten involved in the Bayou Corne incident.

Romero said Texas Brine has installed methane monitors in his house, metal shed, boat shed and outside his house and no gas has been detected.

“I’m just playing wait and see what happens,” Romero said. “If these monitors go off and they get a hit, I may have to get out.”