Corps rushes to address pump corrosion ahead of storm season

Aerial view of the London Avenue Canal Permanent Canal Closure and Pump Station, where corrosion has resulted in a major pump taken out of service for repairs. The Army Corps of Engineers and a joint venture of contractors that built the station are repairing the pump, and smaller temporary pumps will be installed to take the place of the failed pump while it is being repaired. (Google Earth)

With the beginning of hurricane season less than two weeks away, the Army Corps of Engineers and its contractors are rushing to complete temporary repairs of a corrosion-damaged pump at a key New Orleans site.

The Corps again pledged Wednesday to have more than enough pumping capacity in place to handle the upcoming hurricane season, but it remains stumped on what caused the corrosion in the first place, and that investigation is continuing.

"First off, I’d like to reiterate that every level of the Corps of Engineers is engaged in ensuring that these systems are fit to fight for hurricane season 2023, and number two, we remain committed to delivering these systems to meet the 35-year design life specifications" of the pumps, said Col. Cullen Jones, commander of the Corps' New Orleans district office.

The heavily corroded pump is located at the mouth of the London Avenue outfall canal, part of what is known as a Permanent Canal Closure and Pump Station.

The station is one of three at the ends of major drainage canals in New Orleans that include gates to keep out Lake Pontchartrain water in advance of tropical storms. When the gates are closed during storms, the pumps are needed to move rainwater from the canals into the lake.

In July 2021, the Southeast Louisiana Flood Protection Authority-East, which operates the lakefront pump stations, found a pump overheating in the London Avenue station during a routine maintenance check. The cause was determined to be corrosion in February of this year.

This graphic outlines steps the Army Corps of Engineers is taking to assure repairs are completed at the London Avenue Permanent Canal Closure and Pump Station, as the 2023 hurricane season approaches. (Army Corps of Engineers)

Since then, the Corps has inspected all 17 pumps in the three stations, finding corrosion in several other pumps. The joint venture contractor that built the stations is overseeing repair of the London Avenue pump and also repairing corrosion found at several pumps in other stations, though those pumps were not as badly damaged and will be operable on June 1.

Updating the state Coastal Protection and Restoration Authority board at its monthly meeting in Baton Rouge, Jones said that 19 small temporary pumps will be delivered to the London Avenue canal station on Friday, and will be installed and ready to operate by June 1 to make up any difference in pumping capacity while the broken pump is being repaired.

This graphic shows the expected placement of 19 temporary pumps adjacent to the London Avenue Permanent Canal Closure and Pump Station, which will take the place of a pump at the station undergoing repairs, as the 2023 hurricane season begins. (Army Corps of Engineers)

The temporary pumps will be able to move 1,000 cubic feet per second of water from the canal to the lake, about 200 cfs more than the broken pump. While the broken pump is out of service, the station's other five pumps can move 7,200 cubic feet per second from the canal.

Drainage pumps operated by the city's Sewerage & Water Board can deliver a maximum 7,980 cfs into the canal, and the Corps estimates a 10-year rain event would result in 5,211 cfs in the canal.

"Our intent is to keep these pumps in place until Pump #1 has been returned to operation and the full design capacity of the station has been restored," he said, adding that Corps employees have delivered information about the temporary pump installation work door-to-door to residents near the London Avenue canal.

"We want to send out our apologies to the residents in the immediate area as we install and maintain these pumps," he said. "However, it is important to be on the side of caution, rather than to not have this additional capacity."

This photo shows corrosion in a diffuser that is part of a pump at the London Avenue permanent canal closure and pump station. The pump has been out of service since May 2022. (Army Corps of Engineers)

Jones also assured coastal authority chairman Chip Kline that any expenses involving temporary and permanent repairs will be the responsibility of the Corps, and not the state. He said the Corps could also turn to the joint venture company that built the stations for $760 million for some of the repair costs.

Corrosion is obvious in this view of a bearing housing in a pump at the London Avenue permanent canal closure and pump station. (Army Corps of Engineers)

The joint venture that built the stations, which were declared complete in 2018, includes Kiewit Louisiana Co., based in Omaha, Neb.; Traylor Bros. Inc., based in Evansvillle, Ind.; and the M.R. Pittman group, located in St. Rose. The manufacturer of the pumps used in each station was Patterson Pump, based in Georgia.

"Over the last several months, we’ve recognized some of the issues that we’ve had with the pumps and we’ve been working hand in hand with the Corps of Engineers, the pump manufacturer, and our design team to come up with the temporary repairs to assure that we’re ready for the 2023 hurricane season," said Doug Glaser, an executive vice president with Kiewit.

Glaser said the plan is to complete work on the London station pump in 45 to 60 days, and then come up with a long-term plan to assure all the pumps meet their design life requirements.

This closeup of corroded equipment shows that bolts are missing. It's part of a pump at the London Avenue permanent canal closure and pump station. (Army Corps of Engineers)

Jones said all eight pumps at the 17th Street Canal pump station are considered operable. However, stoplogs that block the flow of water are in place around two of the pumps while additional investigations are under way to determine whether they need further repairs.

The continued inspections there are not likely to disrupt that station's pumping capacity, he said. The six remaining operating pumps can move 10,800 cfs of water into the lake, which would increase to 12,600 cfs when the other two pumps are returned to service.

Severe corrosion was found in the pump bearing housing of a pump at the London Avenue permanent canal closure and pump station. (Army Corps of Engineers)

But the maximum amount of water that can be pumped into the canal by the Sewerage & Water Board is only 10,330 cfs, and the required capacity for a 10-year rain event is 9,527 cfs.

All three pumps at the Orleans Avenue canal station are operable. Repair work there included cleaning, coating and the installation of grease shields.

Jones said the longer-term review of the pumps for potential replacement or additional repairs includes having representatives from several of the Corps’ centers for expertise to assist in determining what's causing the erosion. That could include a review of the metals used in building the pumps, the paint or primer, and the effectiveness of electrochemical cathodic protection on metal parts.

One team of experts from the Engineer Research and Development Center, based in Vicksburg, Miss., was arriving this week to conduct testing for microbiologically induced causes of the corrosion.

Jones said his office would mobilize a team by Dec. 1, the day after the end of the hurricane season, to begin work on the longer-term corrective action for the pumps. In the meantime, he’ll be waiting for the joint venture's proposed engineering solution for the problems, which will be discussed with Corps, coastal authority, and levee authority officials before a final plan is approved.

This work is supported with a grant funded by the Walton Family Foundation and administered by the Society of Environmental Journalists.

NOAA is forecasting a hurricane season with a normal range of storms compared to previous years, it announced Thursday.