Water used to cool the Sewerage & Water Board’s heavy equipment has for many decades then been pumped out to customers across New Orleans’ east bank because of archaic engineering that violates public health regulations, officials said Tuesday.

While city and state officials say the design of the Carrollton water treatment plant has not caused any known problems, it raises concerns that the water sent to tens of thousands of homes and businesses could become contaminated.

“This is the way the plant has been for over 100 years. The water has been safe to drink, and there are reinforced testing requirements going forward,” said Dr. Joseph Kanter, an assistant state health officer and former director of the New Orleans Health Department.

The design “is a known potential source of contamination," but based on all evidence available to officials, "there has not been any actual contamination,” he said. 

The S&WB publicly disclosed the problem Tuesday, and the state Department of Health, which had already been briefed about it, formally issued a notice of violation later in the day.

The revelation has prompted stepped-up water monitoring by the S&WB, and officials promised an aggressive push to upgrade or sideline the turbines and pumps now being cooled with drinking water.

In the end, the problems could be the final catalyst that leads the S&WB to move away from generating its own power and turn to relying on Entergy New Orleans for the power to keep its systems running. That move has been contemplated for years and generated renewed interest in the wake of flooding in 2017, but it has always been seen as a long-term goal.

“This (revelation) is speeding up and emphasizing the need for getting rid of that (self-generated) steam power,” said S&WB Executive Director Ghassan Korban, who joined the agency five months ago. “There’s always a silver lining, and that’s what I’m seeing it as.”

New Orleans residents have grown used to questioning their drinking water during pressure drops that result in boil-water advisories — the latest of which, covering large parts of the 9th Ward — was lifted on Tuesday. But the revelation about the water treatment plant’s machinery introduces a new concern over how contaminants could get into the system.

Under the current system, water that has been treated to make it safe for drinking is kept in a “clear well” before being pumped out across the east bank.

But copper pipes also draw off millions of gallons of water a day from that well to cool four of the S&WB’s five power turbines and the two pumps that push the clean water across the east bank. After the water has cooled off that equipment, it is then dumped back into the well to be distributed to customers.

Such a set-up has been prohibited by state regulations for as long as they have existed, said John Williams, the deputy chief engineer for the state Department of Health. Those rules, however, would have been issued long after the cooling system was put in place around 1906.

While the pipes prevent the water from coming in direct contact with the machinery they’re cooling, a breach could allow potentially dangerous impurities — either chemicals or metal particles from the equipment or bacteria from the air — into the water supply.

It’s not clear why the arrangement did not cause concern in the past.

“This cross-connection is not something that is immediately visible. It was uncovered by a very thorough investigation by the Jacobs Engineering Group,” Kanter said.

Jacobs was initially hired to determine why one of the S&WB’s turbines was having trouble staying cool enough to operate at full capacity. In the course of that investigation, the firm discovered how the water was being recirculated.

For now, the S&WB has put in place more stringent monitoring to check the water supply for impurities as it leaves the Carrollton plant. Testing now is occurring four days a week, and the utility is moving toward constant monitoring of the water, Korban said.

The utility will also move to either convert its equipment so that it can be used without water cooling or else decommission it over the next five years, he said.

That would force the utility to stop relying on Turbine 4, which was just brought back online last year after $30 million in repairs, as its main power source, since that turbine uses the most water, Korban said. Instead, it will use another turbine that requires far less water, he said.

Turbine 4 could eventually be returned to service after being upgraded so that it no longer needs water for cooling. 

Two other turbines will be sidelined in favor of electrical generators that were purchased to bolster the S&WB’s power capacity in the wake of the 2017 flooding. And a third could be replaced by purchasing energy converters that would allow power from Entergy to be changed over to the unusual standard used by much of the S&WB’s equipment.

The turbines to be taken out of service would be kept on standby in case they are needed, Korban said.

Longer term, the utility will take steps to depend on Entergy to power its entire system. Such a move would save money in the long run, since Entergy can provide power at about a quarter of what the S&WB now pays to generate it, but the changeover would have a substantial price tag, likely about $50 million, Korban said.

“We are going to save a tremendous amount of money and maintenance by taking that expensive equipment offline,” he said.

Until then, it’s unclear where the cash-strapped utility can find the money to make the changes, though S&WB officials suggested some assistance could come from state or federal coffers.

Mayor LaToya Cantrell, who serves as president of the S&WB, also used the opportunity to once again push her plan to redirect some tax revenue from tourism and hospitality groups to fund infrastructure needs in the city.

“We’re going to need an additional infusion of resources that will benefit everybody,” Cantrell said.

Follow Jeff Adelson on Twitter, @jadelson.​