A state legislative committee is scheduled to hold a public hearing Thursday in New Iberia to explore concerns that the expansion of a natural gas storage facility in Iberia Parish could affect drinking water in the region.

AGL Resources has applied for a state permit to expand its Jefferson Island Storage & Hub facility at Lake Peigneur, where billions of cubic feet of natural gas are stored underground in hollowed salt domes.

The company’s plan has met strong opposition from residents who say they worry about the safety of the site and about impacts to the Chicot Aquifer, the region’s main source of water for drinking and agricultural irrigation.

The topic of the Thursday hearing is the groundwater issue.

“We have been trying to impress on local officials that if this goes through, we will have major problems with the aquifer,” said Nara Crowley, president of the advocacy group Save Lake Peigneur.

The possible impact to the Chicot Aquifer is not directly related to the storage of the natural gas but rather to the process of creating the massive underground storage caverns.

AGL is proposing to pump as much as 3 million gallons a day from the Upper Chicot Aquifer over about three years to scour out the salt dome and create two new storage areas under Lake Peigneur.

The Upper Chicot Aquifer is the layer of the aquifer that contains fresh water used for drinking and irrigation.

Opponents argue that using so much water will pull down levels in the aquifer so far that saltwater from farther south will begin creeping northward to fill in the void.

Louisiana Water Company, which supplies water to New Iberia, has also raised concerns about possible arsenic contamination to its wells related to the drawdown of the aquifer at the AGL site.

LAWCO officials have said that arsenic from a contaminated area near New Iberia could be pulled into the city’s wells as water migrates underground to recharge the portion of aquifer that AGL plans to tap.

AGL Senior Director of Governmental Relations Richard Hyde said the company’s research has found no anticipated problems with the aquifer, adding that the state Department of Natural Resources is obligated to evaluate groundwater impacts before granting the permit.

“At the end of the day, we are not trying to harm water sources,” Hyde said.

The withdrawal of 3 million gallons a day from the Upper Chicot Aquifer represents less than 1 percent of all daily withdrawals for the region, according to figures from AGL.

The hearing in New Iberia follows a similar hearing in May before the state Senate Environmental Quality Committee in Baton Rouge.

The most vocal concerns at that hearing came from state Sen. Fred Mills, R-Parks, who is not a member of the committee but sat in on the hearing.

Mills suggested that AGL “throttle back” its plans to allow time to carefully study impacts to the aquifer “and just maybe make sure that we are not missing anything in the process.”

The hearing of the House and Senate Joint Environment Committee is scheduled for 5:30 p.m. Thursday at the Sliman Theater, 129 East Main St. in New Iberia.