Under pressure from local officials, the U.S. Army Corps of Engineers has agreed to coat the steel sheetpiling that will be used to upgrade a New Orleans canal that breached during Hurricane Katrina.
USACE has awarded a $17.9 million contract to shore up the London Avenue Canal floodwalls and levees—a project that will now include applying protective coating to 6,000 feet of sheetpile, at the request of the Southeast Louisiana Flood Protection Authority-East.
The Authority and USACE have been locked in a bitter dispute for a year over whether to apply protective coatings to the steel sheetpiling that is being used to rebuild and repair New Orleans’ levees.
‘An Imprudent Decision’
Local and regional officials have demanded that the steel be coated, saying their experts insist that coating will extend the levee’s life and reduce maintenance.
"We have counseled them for months that ... the use of untreated steel in the marine environment was an imprudent decision, and we asked people with more expertise to look at it, and they agreed it was imprudent," levee commissioner Steve Estopinal, an engineer and surveyor, told the local newspaper over the summer.
Estopinal sponsored a successful resolution to fast-track an external peer review of the situation. That review has not yet begun.
"We want future steel coated, and if the external peer review comes back and agrees with us . . . the federal government should be required to pay for the [monitoring] and maintenance of those walls." Estopinal called the use of untreated pilings "a design flaw."
No Time for Coatings
The Army Corps, however, decided last year to forego protective coatings on 50,000 steel sheetpilings used to build about 23 miles of new levee encircling St. Bernard Parish, which was hit hardest by Katrina.
To speed up the project, USACE opted instead to use oversized pilings with an extra 1/8-inch layer of “sacrificial steel” that can corrode and, the Corps says, still maintain specifications.
The Corps contends that the sacrificial steel method offers better corrosion protection than coatings at about the same cost. The Corps said the project deadline did not allow time for coating the St. Bernard levee sheetpile.
The debate continues years of bad blood between the locals and the Army Corps. The Corps built the levee system that failed during Katrina, flooding the parish and killing dozens of people.
Currently, the Corps is racing against a June 1, 2011, deadline to complete the entire project: a $14.4 billion, 100-year Hurricane and Storm Damage Risk Reduction System (HSDRRS) for southeast Louisiana. The system includes five parishes, 350 miles of levees and floodwalls, and 73 pumping stations.
Canal Pilings to Be Coated
But coatings will be used in the London Avenue Canal project, USACE spokeswoman Nancy Allen confirmed Thursday (Dec. 9).
That project contract, awarded Tuesday (Dec. 7), calls for driving steel sheetpile through the sand layer on the berm side of the floodwalls to prevent seepage, and for adding embankment at the crown of the levee to reduce “floodwall stick-up.”
Two of the three major breaches during Katrina occurred on the 15,000-foot-long London Avenue Canal, with much of the problem later traced to seepage, Allen said. London Avenue is one of three “outfall” canals that drain water from the city into Lake Ponchartrain.
The goal of the six-month canal project is to repair and shore up the weakest sections of floodwall and levee to increase the “safe water” level in both channels to eight feet. The current elevation at London Avenue is capped at five feet.
The project will be done by New Orleans-based Integrated Pro Services, LLC. Construction is expected to begin in January.
‘Just a Different Plan’
Allen said the decision to use coatings on the London Avenue Canal project did not signal a change for the Corps. She noted that the agency had used a variety of corrosion-protection measures throughout the HSDRR System.
In this case, she said, the Corps was acceding to a specific request from local officials—a request that this project is small enough to accommodate, she added.
“The three projects in St. Bernard were extraordinarily large,” Allen said. “The contractors told us we could not finish within our deadline if we used coating.
“In this particular case, it’s a very small amount of work; it’s pretty minor and it did not have an impact on our deadline.
“It’s not that we changed our mind; it’s just a different plan.”
Corrosion Control Options
In July, Col. Robert Sinkler, Commander of the USACE Hurricane Protection Office (HPO), attended an Authority meeting to defend the Corps’ decision and review the corrosion-inhibiting measures being used on the project. They are, he said:
• Over-sized cross-sections of piles (addition of a corrosion allowance)
• Coal tar epoxy or other coating
• Application of a polyethylene sleeve
• Zinc coating
• Electro-chemical (cathodic) protection
• Casting in cement, mortar or concrete
Sinkler said that the system’s design guidelines did not specifically address corrosion.
A USACE official told PaintSquare News in September that coating the pilings “would have overwhelmed the coatings industry."
The cost difference between coating and sacrificial steel is “negligible,” said Allen, but she would not provide specifics.
“I don’t think that’s something we can discuss,” she said. “It is protected information, proprietary information."
But she added: “Cost did not factor into it. Time was the important factor.”
Flood Protection Authority officials could not be reached for comment Thursday.
Contracts to upgrade the other two canals have not been awarded, but coatings are expected to be part of those specs, Allen said.