The Capital Area Ground Water Conservation Commission decided Tuesday to double the water fee it charges in order to pay for wells to help track salt water in the aquifer under Baton Rouge, but residential customers will see an increase of only pennies to their bills.

The commission charges $5 per million gallons used to regulated users to help pay for commission work. On Tuesday, the board approved raising that to $10 per million gallons to the 58 regulated users in the parishes of East Baton Rouge, West Baton Rouge, East Feliciana, West Feliciana and Pointe Coupee.

The commission has the authority to raise fees to deal with saltwater intrusion in the Southern Hills Aquifer, which provides drinking and industrial water to Baton Rouge.

Commissioners decided against an option of paying for the test wells by splitting the cost among just the regulated users in the 2,000-foot sand instead of across the board. That option needed legislative approval, and the commission has found it difficult to find anyone to sponsor such a bill.

“Going back to the Legislature for a change is not the path we need to go down,” Commissioner Dale Aucoin said.

Commissioners voted 8-2 in favor of an across-the-board fee increase, with three commissioners abstaining from the vote.

Commission members representing the Baton Rouge Water Company, which along with West Baton Rouge Parish’s representative favored the 2,000-foot sand option, said it was difficult to give customers the exact amount their bills would increase. Other commissioners said residential customers currently pay 3 cents to 9 cents a month in water fees, so it’s unlikely anyone will even notice when that amount doubles.

The higher fee applies to any customer using 50,000 gallons or more water a day. Exemptions include users taking water out of the Mississippi River alluvial aquifer, those with wells of less than 400 feet in depth and agricultural customers.

The fees won’t be official until the commission holds public hearings and does other administrative work — likely to take five or six months.

The fee increase will raise the $250,000 a year needed for exploratory wells in the 2,000-foot layer of the Southern Hills Aquifer under downtown Baton Rouge. The wells will help the commission address saltwater intrusion into this part of the multilayered aquifer.

Aucoin said the commission’s master plan calls for a 3.5 million gallons a day reduction of industrial pumping from the 2,000-foot aquifer layer. The scavenger wells will be used to prevent salt water from moving farther north to other wells.

Industrial users already have accomplished the pumping reduction and “it’s time to move on with the next phase of this,” Aucoin said. New test wells are needed to provide more information about where the scavenger wells should be put to do the most good.

“We don’t feel industry should carry the full cost of these test wells,” said Aucoin, who is with ExxonMobil and represents industry on the commission. “Industries are ready to fund their share.”

Jeff Miller, Baton Rouge Water Company’s commissioner, said the second option requiring legislative approval was a better approach. At the technical committee meeting last week, Miller advocated for industrial users of the 2,000-foot sand to voluntarily pay for the needed test wells.

Aucoin said that wasn’t well received in the past because no company wants to be put on the hook for paying all of the cost and it was better for all to pay a part.

Follow Amy Wold on Twitter, @awold10.