The saltwater wedge moving up the Mississippi River has cities downriver of Baton Rouge on high alert to keep supplied with fresh drinking water.
New Orleans and Jefferson Parish officials are planning to build multi-million-dollar temporary pipelines to tap river water miles upstream of their treatment plants and away from the salt, while other locales are relying on or are planning to rely on imported fresh water.
Baton Rouge has its own issue with salt water invading its fresh water supply, experts and water providers say, a slow-motion problem decades in the making.
Though the dry conditions have increased demand and consequently pumping enough to test the system of local water provider, Baton Rouge Water Co., the saltwater intrusion isn’t related to a low-flowing Mississippi River spurred by months of dry conditions across the Midwest.
For drinking water, Baton Rouge and most of the parishes in its suburbs count on the Southern Hills aquifer, a deep underground water source that is disconnected from the Mississippi and is largely protected from the river’s current temporary increases in salinity.
Stretching from just west of the Mississippi River across the Florida Parishes to the boot toe of Louisiana, the aquifer is recharged by rainfall in the southwestern corner of the state of Mississippi.
Over years, however, heavy groundwater pumping in the Baton Rouge area has slowly drawn salty groundwater that exists south of the city across a protective fault into the ample freshwater stocks. The salt movement has gradually gone north toward the city’s and industry’s drinking water and supply wells, experts have said.
Facing requests to drill new wells in recent months, a state regulatory district and oversight panel that manages the aquifer is considering a temporary moratorium on new well drilling in parts of Baton Rouge. The group learned in May that the saltwater intrusion has continued to worsen over the past two decades.
Gary Beard, director of the Capital Area Groundwater Conservation District, said a pre-existing U.S. Geological Survey model of the aquifer and a newer one being refined by LSU researcher Frank Tsai and the Water Institute of the Gulf have recently reached the same conclusion.
“They both indicated the same thing, that if we did nothing, status quo, everyone pumping the same amount right now and added no new production, the saltwater intrusion is going to get worse, which is past the point of equilibrium. It’s going to continue to get worse,” Beard said.
A technical panel of the commission overseeing the district has already recommended the temporary moratorium to give researchers time to refine their work, he said.
Beard said the moratorium area would exist between the Baton Rouge fault and two others to the north known as the Scotlandville and Denham Springs faults.
These three faults roughly run in the same east-west line as the two Mississippi River bridges at Interstate-10 and north at U.S. 190, Beard said. The area covers a region where many water production wells are located.
Some commissioners, however, weren’t ready for such a serious step.
The commission held off last month on acting on the idea to study it further, possibly for a meeting in November.
In the interim, the panel also delayed action on two new wells recently proposed in East and West Baton Rouge parishes.
The stalled wells would supply drinking water to West Baton Rouge Parish and to Baton Rouge Water Co., which has more than 190,000 customers in East Baton Rouge Parish and northeastern Ascension and Iberville parishes.
Kellie McNamara, deputy director of the six-parish district and its commission, said the two wells would have a “detrimental impact” on areas “of known saltwater intrusion.”
McNamara said the panel has asked the applicants for additional modeling to find drilling depths and pumping rates to withdraw water “without worsening the saltwater issue.”
Calling the moratorium premature, Patrick Kerr, president and CEO of Baton Rouge Water Co. and a former chairman of the groundwater commission, said the panel is acting without any underlying regulatory rules to enact the moratorium.
He added that the commission and its staff haven’t done the advance political work they should be doing by speaking to local officials to explain the regulatory step.
Kerr said saltwater intrusion is real and the company is trying to move its infrastructure north and away from the salt as quickly as possible but contends it isn’t an emergency either.
“I think we’re doing our part. I think more work needs to be done before they declare a moratorium,” he said.
In a meeting last month on the moratorium and well deferral, Kerr also warned the commission that delaying its new well could eventually endanger fire protection and the saving of the life of “some child who is stuck in a bedroom,” according to a transcript.
Kerr told the panel the well would be used for backup emergency supply in times of need.
Commissioners objected to what one of them termed “almost a threatening characterization,” though Kerr said it wasn’t intended to be that but more a reflection of the possibility.
The delay on Baton Rouge Water’s well comes amid a bristling legal fight between Baton Rouge Water and the commission.
Under fire from the state Legislative Auditor’s Office and state Office of Conservation for not doing enough to halt intrusion over its nearly 50 years of existence, the commission was refashioned in recent years with new leadership and has pursued real-time metering of the region’s major production wells.
Tsai, the LSU researcher, has said that level of detailed pumping data was needed to create more-accurate models of the impact of well pumping and long-term forecasts of water demand.
Baton Rouge Water, however, has countered the metering plan is too expensive and redundant because the company is willing to provide its own metering data. The two sides are headed to state court later this month for a key hearing.
According to the USGS’s latest findings, between 2003 and 2022, underground salt has continued to spread out or salt concentrations have continued to rise in seven of the 10 drinking water-bearing sand layers of the Southern Hills aquifer.
The rising salt concentrations have included areas around some existing drinking water supply wells, the analysis shows.