The commission in charge of addressing saltwater intrusion in the aquifer that serves Baton Rouge on Tuesday approved well testing to determine just where that salt water is located.
The Capital Area Ground Water Conservation Commission approved spending $44,100 to sample for salt water in the 2,000 foot layer of sand in the portion of the Southern Hills Aquifer that runs through Baton Rouge.
For decades, increased pumping on the north side of the Baton Rouge fault — roughly along Interstate 10 through Baton Rouge — has pulled salt water closer to wells used for both residential drinking and for industry.
The commission, in cooperation with the U.S. Geological Survey, has been designing models of how that salt water is moving through different layers of sand in the aquifer.
The money approved Tuesday will go toward testing water in two wells, at Lafayette Street and Convention Street in Baton Rouge, in part to determine how closely those models match what’s really happening underground and to help guide future action.
The wells are owned by the private Baton Rouge Water Company, which has been planning to have both wells down for about a month for maintenance and agreed to the testing, said commission director Tony Duplechin.
The work involves much more than just pulling up a water sample and testing it. Pumping equipment has to be installed and removed, instruments need to be lowered into the well, then everything needs to be removed, and the well reassembled and chlorinated before it can be returned to service.
Duplechin said the water company saved the commission thousands of dollars by allowing the agency to test the company’s existing wells, since it can cost $200,000 to drill a new one. Initially, the commission thought it would have to drill three wells in order to get enough information on where to put in a scavenger well that draws out salt water before it gets to drinking or industrial wells. However, the commission now may just need to drill one additional well to make its decision.
A scavenger well pumps out salt water ahead of wells where fresh water is needed and is the solution the commission has chosen for addressing saltwater intrusion in the 2,000 foot aquifer layer.
Others, though, have maintained the solution is for industry to stop using groundwater and instead take their water from the Mississippi River as industries south of Baton Rouge do.
Duplechin emphasized that this is not another study but is the first step in addressing the saltwater intrusion.
The commission also is planning to include $250,000 in next fiscal year’s budget that would go toward additional well drilling if needed.
The work on the two well tests in downtown Baton Rouge will start within the next few weeks and will take about two weeks per well.
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