Once again, residents across a swath of New Orleans were told to avoid drinking water from their taps after pressure dropped in the 9th Ward while Sewerage & Water Board workers were testing a valve Monday morning.

The public utility issued a boil-water advisory for parts of the Upper 9th Ward, from Almonaster Avenue east to the Industrial Canal, and the entirety of the Lower 9th Ward.

The affected area included portions of the St. Claude, Bywater, Florida and Desire neighborhoods but not New Orleans East. 

Residents were urged to boil tap water for at least one minute before drinking it or using it to brush their teeth, make ice or cook or clean food. 

Residents have long grown weary of the pressure drops and accompanying warnings that have plagued the S&WB’s water system. Including the incident on Monday, there have been 17 advisories covering all or parts of the city since 2012.

On Monday, a political action committee tied to Mayor LaToya Cantrell — who sits as president of the S&WB — sought to seize on that frustration to continue her push to rededicate tax revenues from tourism and hospitality groups to an infrastructure fund.

Boil advisories are intended to ensure that potentially harmful microbes have not made their way into the pipes that carry the city’s water while the pressure is low. It typically takes about 24 hours for officials to conduct the tests needed to verify that the water supply remains uncontaminated.

Tests during each of the 15 previous advisories came back without any sign the pressure drop had caused contamination.

The warning on Monday came while crews were testing valves related to work being done on the Southeast Louisiana Urban Flood Control Project on Florida Avenue, part of a massive regional drainage project overseen by the U.S. Army Corps of Engineers, S&WB spokesman Curtis Elmore said. During the test, pressure dropped unexpectedly, he said.

The workers immediately suspended the test and restored pressure, and S&WB teams are still investigating the exact cause of the drop, Elmore said.

Water pressure in the area dropped to 17 pounds per square inch starting about 10:08 a.m. Pressure was restored about 10 minutes later, Elmore said.

The advisory was sent out about 90 minutes later.

State Department of Health guidelines call for a boil-water advisory anytime pressure drops below 20 psi under a new standard implemented last summer. Under the previous standard, which only called for an advisory when pressure fell below 15 psi, a boil-water advisory would not have been required Monday.

Councilman Jay H. Banks, who was appointed to the S&WB at the end of last year, said he understood residents’ frustrations with the advisories. But even though he said there was a sense of urgency at the S&WB to fix the problems, he warned this would likely not be the last time New Orleanians were told to turn to bottled water.

“This stuff is bad, there’s no qualifying that,” Banks said of the repeated warnings. “And it’s going to break again before it gets fixed.”

Though he said solving the problems with the S&WB’s water system is “going to be a long process,” he added that “the one piece of shining light in this, is that we get it and we’re working to make this the exception and not the rule.”

Meanwhile, Action New Orleans, a group formed to support Cantrell, seized on Monday’s advisory to once again push for the mayor’s plan to redirect some of the hotel tax money that now goes to the Ernest N. Morial Convention Center, the Mercedes-Benz Superdome and tourism promotion groups to pay for infrastructure upgrades.

An email sent to the organization’s supporters Monday declared that “boil water advisories are not normal” — a sentiment that many in the city likely wish was true in New Orleans.

“Tired of having to boil water? More of our tourism taxes get diverted away from city services than (in) any other destination city in the United States,” the email stated before encouraging readers to contact their legislators in support of Cantrell’s infrastructure plan.

During a boil-water advisory, healthy adults should avoid drinking tap water that has not been brought to a boil for a full minute, though they can continue to bathe or shower as long as they don't ingest any water.

Precautions should be taken to ensure young children do not ingest water.

People with open wounds, chronic illnesses or weakened immune systems are advised to use only boiled or bottled water for any purpose until the advisory is lifted.

Editor's note: This story was updated on Feb. 5, 2019 to correct the number of boil water advisories that have been issued in New Orleans since 2012. Monday's boil water advisory was the 17th time an advisory has been issued for all or part of the city.

Follow Jeff Adelson on Twitter, @jadelson.​