Local flood-protection officials in New Orleans are locked in a disagreement with the U.S. Army Corps of Engineers over its refusal to coat steel pilings destined for new levees around communities demolished by Hurricane Katrina.
At issue are completely conflicting professional opinions over the corrosion protection and future structural integrity of 50,000 steel sheet pilings now being used to build about 23 miles of new levee that will encircle St. Bernard Parish, which suffered the worst of New Orleans’ devastation by Hurricane Katrina.
It is an enormously emotional debate and follows years of bad blood between St. Bernard Parish and USACE officials. During Katrina, the levee system built by the USACE catastrophically failed, flooding the entire parish and claiming at least 34 lives.
The current dispute involves a three-segment, 23-mile continuous stretch of flood wall that is part of 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.
USACE decided last fall not to apply protective coatings to the pilings in that section, opting 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.
Coating the pilings would have driven the project well past schedule, the Corps says. Although isolated individual sections of the overall levee project are using uncoated steel and steel components, this is the longest continuous segment in the system that will do so, USACE said.
Construction of the disputed segment is well underway, and the Corps says it is under presidential, congressional, state and local pressure to make a completion deadline of June 1, 2011.
However, the Southeast Louisiana Flood Protection Authority-East, which is overseeing the flood project, wants the steel coated, saying it will extend the levee’s life and reduce maintenance. Opposition to the plan has consumed months of the Authority’s meetings.
At the panel’s request, Col. Robert Sinkler, Commander of the USACE Hurricane Protection Office (HPO), attended an Authority meeting in July to defend the Corps’ decision.
Sinkler reviewed the six corrosion-inhibiting measures being used in various locations throughout the Hurricane and Storm Damage Risk Reduction System outside the disputed area:
• Over-sized cross-sections of piles (addition of a corrosion allowance)
• Coal tar epoxy or other coating
• Application of a polyethylene sleeve (on steel pipe piles)
• Zinc coating
• Electro-chemical (cathodic) protection
• Casting in cement, mortar or concrete
Sinkler said that the current HSDRRS design guidelines did not specifically address corrosion, according to the meeting minutes. The guidelines include a chapter on painting using only coal tar epoxy; however, it does not say that other measures cannot be used to inhibit corrosion, he said.
Still unsatisfied, the state Office of Coastal Protection and Restoration and the Southeast Louisiana Flood Protection Authority-East have initiated an independent peer review of the practice.
‘Substantial Scheduling Advantages’
Dr. John Grieshaber, Chief of Execution Support for the Hurricane Protection Office, U.S. Army Corps of Engineers, said in an interview Tuesday (Sept. 21) that the Corps consulted with its contractors on the corrosion issue before work on the three segments began.
“All three said that trying to put some kind of coating on the piles was going to have some tremendous impact on the schedule,” Grieshaber said. “If they could eliminate the coatings, there would be substantial scheduling advantages.”
Coating the pilings also “would have overwhelmed the coatings industry,” Grieshaber added.
He contended that the “sacrificial steel” approach is an appropriate option in the agency’s Engineering Manual 1110-2-2504: Design of Sheet Pile Walls.
Grieshaber said sacrificial steel would not shorten the levees’ life, increase maintenance, or affect the project’s cost. Overall, more than 100,000 tons of additional steel will be used in the system to compensate for potential corrosion, the Corps says.
“We consider it possibly to be a longer life than the coating option,” he said. “Post-Katrina, we pulled a lot of [uncoated] steel out of the ground, and we saw no corrosion. Some still had mill scale on it.”
‘An Imprudent Decision’
Local authorities strongly disagree. "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," said levee commissioner Steve Estopinal, an engineer and surveyor, who introduced a successful resolution last week to fast-track the peer review, according to the Times-Picayune.
"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."
Neither Estopinal nor commission chairman Tim Doody could be reached Tuesday for comment.
The peer review will be led by the scientific nonprofit group Battelle. However, construction could be complete—or nearly so—by the time the review process plays out. USACE has not yet given Battelle its documentation, Grieshaber said Tuesday. After that, Battelle will have to recruit experts to conduct the review. Only then can the actual review begin.
Meanwhile, construction is well underway on each of the three segments, known by their project prefix of LPV (Lake Pontchartrain & Vicinity):
• LPV 145: All of the steel is expected to be driven by early October, USACE said. The contractor is Chalmette Levee Constructors, a joint venture group of three Midwestern contractors.
• LPV 146: All of the sheet piles are already in, as well as 40% of the H piles. The contractor is a partnership called St. Bernard Levee Partners.
• LPV 148: Construction on this segment has just begun. The contractor is Cajun Constructors Inc., of Baton Rouge, LA.