Saltwater from the gulf impacts Plaquemines Parish’s water system

NEW ORLEANS (WVUE) - Plaquemines Parish issued a drinking water advisory late Wednesday afternoon (Sept. 23) due to a saltwater wedge that is moving up the Mississippi River. Earlier in the day, the U.S. Army Corps of Engineers held a press conference to discuss how it plans to address the saltwater intrusion that is impacting Plaquemines Parish.

Like a lot of things, the Mississippi River can be inconsistent.

David Ramirez is the Corps’ Chief of the River Engineering Branch.

“Right now the Mississippi River is in what we call a low-flow condition, so the water from upstream, it’s the lowest it’s been in about 10 years, 10 or 11 years and when the river water, the flow gets slow salt water from the Gulf of Mexico moves its way upstream into the river channel because salt water is denser than freshwater,” said Ramirez.

And that situation can threaten municipal and industrial water systems.

“In Plaquemines Parish, there’s many freshwater intakes for municipal, industrial uses and the salt water can cause corrosion to pipes and can cause a change in the taste of the water for municipal use, so we try to, that’s why we’re involved to mitigate that,” said Ramirez.

So the corps will construct an underwater barrier.

Health Jones is the Corps’ Emergency Manager for the New Orleans District.

“We have reached a trigger to install an underwater sill on the bottom of the Mississippi River, at about mile 63. We expect construction to begin in about three weeks and be done by early November,” he said.

The saltwater wedge is said to be located just above Pointe-a-la-Hache. And the levee is going to be built 12 river miles below Belle Chasse in Plaquemines Parish.

“It’s basically like an underwater levee. We select a section in the river, and we use a dredge, and they borrow material from a portion of the river that has like plenty of material, and they build an underwater, like a levee basically to stop it, because that saltwater moves below the fresh water so that underwater sill or levee stops the progression of that saltwater upstream,” said Ramirez. “Wherever we build the sill that saltwater will stop there.”

The levee will be high.

“We build the sill up to from -95 to -45, so it’s about 50 feet high, 50-foot-high levee in the bottom of the river to stop that salt water,” said Ramirez.

Plaquemines Parish President Kirk Lepine says they have a plan to ensure there is enough water supply.

“We have secured two reverse osmosis machines that will run at the Boothville plant and at the East Pointe-a-la-Hache plant. They will produce 1 million gallons of water, what they’re doing now,” he said. “These plants are there to take out the chloride that’s in the water and produce the water that continues to be produced every day, so we will not lose water function in those systems.”

Lepine says the two reverse osmosis machines $40,000 each per month. “So, we will tackle that payment later but we have secured two machines, they are coming out of Kentucky, they should be here by Friday,” he said.

And on the drinking water advisory, the parish’s press release said it is recommended that people who are on dialysis or on a low-sodium diet check with their health care providers related to the levels of chloride and sodium in their drinking water.

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