White House declares emergency, pipeline planned as salt threatens drinking water - NOLA.com

White House declares emergency as salt threatens water | Environment | nola.com

The White House declared an emergency Wednesday for four Louisiana parishes threatened by salt intrusion in drinking water and officials warned that barges would be insufficient to deal with the problem on the east bank of New Orleans and Jefferson, prompting an urgent plan to build a pipeline.

The declaration was key since it frees up federal money for the response, which is shaping up to be a highly expensive proposition. New Orleans is preparing to deal with salt intrusion for a three-month period– meaning through January under current forecasts.

Still, officials from across the region urged residents not to panic, and stressed water in the New Orleans area remained safe to drink. Sufficient warnings would be issued should that change, and backup plans were being looked at, including providing bottled water and implementing water conservation methods, they said.

The emergency declaration specified Plaquemines, Orleans, Jefferson and St. Bernard parishes. Plaquemines has already been dealing with the problem by distributing bottled water for some areas and using water from Belle Chasse to blend with supplies further downriver.

Gary Sylvester with the Plaquemines Parish Flood Control drives a palate of bottled water into a shipping container in Braithwaite, Louisiana. He and his coworkers were stockpiling for, if and when, saltwater flows past their community just a few miles above the saltwater wedge that is slowly moving up river on Monday, September 25, 2023. (Photo by Chris Granger | The Times-Picayune | NOLA.com)

"We’re not in a doomsday situation by any means," Collin Arnold, New Orleans’ director of homeland security and emergency preparedness, said at a City Council committee meeting. He added later: “This is a manageable situation.”

One month away

But much remained unknown about the highly unusual dilemma facing New Orleans and its suburbs. Ultimately, enough rain must fall further north in the Mississippi River basin to flush out the salt water moving up from the Gulf of Mexico. But forecasts so far show that not happening soon, with the river’s flow staying well below the level required.

Under current forecasts, salt would reach New Orleans’ Carrollton plant, which serves the city’s east bank, around Oct. 28 and the East Jefferson waterworks the following day. The salt is currently located about six miles south of Belle Chasse, having overtopped a sill, or underwater levee, built by the Army Corps of Engineers on Sept. 20. The Corps is in the process of expanding that sill.

NO.sillwork

Because of the huge volume of water processed by the east bank plants for New Orleans and Jefferson Parish, barging water in to dilute the salt, as initially envisioned, will not be sufficient, officials said. Instead, the most viable plan is to quickly build a pipeline that would pump water from around Kenner downstream for use at the two plants.

That location would be used because of a natural feature at the river bottom that could stall the salt water, sometimes called the “Kenner hump.”

The temporary solution could then potentially be transformed into a permanent one, which may prove necessary if drought conditions in the Midwest become more frequent, limiting the flow of fresh water down the river.

But even the temporary pipeline will be hugely expensive. Steve Nelson, deputy general superintendent at New Orleans’ Sewerage and Water Board, said cost estimates range from $100 million to $250 million, “but the fact of the matter is we just don’t know exactly what that is at this point.”

A request with those estimates has been made to the federal government. Construction has not yet begun, but Arnold was hopeful it could start in seven to 10 days, and contractors were assuring it could be built in time given expedited processes allowed in emergencies.

The city was preparing for other solutions should there be a gap between when the pipeline is finished and the arrival of the salt. Those include the possibility of providing bottled water and taking measures to conserve water.

Nelson said the S&WB could not go ahead with the pipeline project on its own because of the high cost.

“It comes at a very high capital cost, greater than we at the Sewerage and Water Board would have the authority to pull the trigger on,” he said.

Barges were still part of the plan on the west bank of New Orleans and Jefferson, officials said. New Orleans’ Algiers plant processes 15 million gallons per day compared to the Carrollton plant’s 150 million gallons.

Officials noted that water would remain available regardless for non-drinking and non-cooking purposes, such as toilet flushing, bathing, washing clothes and firefighting.

'Not like a hurricane'

The advance of what is known as the saltwater wedge has posed a perplexing problem for the Corps. As it has done in the past, including last year, the Corps initially built a sill, or underwater levee, in July to block its advance, but it proved insufficient.

The sill was initially built to a height of about 55 feet below the river’s surface to continue to allow shipping along one of the world’s most important transportation lanes. But the salt water overtopped the sill built near Myrtle Grove.

In response, the Corps has begun heightening the sill to 30 feet below the surface, but with a 620-foot-long notch in the middle that will continue to allow shipping. The heightened sill will only slow the salt water’s advance.

Col. Cullen Jones, the Corps’ New Orleans district commander, said Wednesday that the river’s current flow was only about half of the 300,000 cubic feet per second needed to flush out the salt.

Jefferson Parish President Cynthia Lee Sheng assured residents that drinking water will be "readily available.”

"This is not like a hurricane where sometimes we get 120 hours to prepare. We have time to prepare," she said.

Merritt Lane, CEO of Canal Barge, said barge operators have been contacted by contractors for the Corps to determine their capacity to transport large tanks of freshwater to water intakes along the affected parts of the river.

"We still don't know what the scope will be, what equipment will be needed, what it will look like. It's all very fluid at present," Lane said.

Staff writers Mark Schleifstein, Marie Fazio and Stephanie Riegel contributed to this report.