NEW ORLEANS (AP) — Utility companies have warned for years about the hazards of Mylar balloons and that message was resounding Thursday across New Orleans as most of the city’s nearly 370,000 residents remained under a boil water advisory after a wayward balloon hit power lines near a treatment plant.

The metallic, film-coated balloons are pretty, shiny things when they leave one’s hand. Balloon releases are a popular way to celebrate big events. But they are litter when they come down. And environmentalists have long complained about the dangers they pose to wildlife. And, as New Orleans was reminded this week, they can be a big problem for utilities.

What happened in New Orleans?

Entergy New Orleans, which supplies electricity in the city, said a floating Mylar balloon struck a power line near the water plant Tuesday night. It just caused a momentary “flicker” of power at the facility. But the head of the agency that runs the city’s drinking water, sewerage and street drainage systems said that was enough to knock out four key pumps that keep the water flowing.

An unspecified injury to one of the workers tasked with getting pumps started again caused a delay that allowed water pressure to drop. Low pressure can allow bacteria to enter leaks in the system, so, as a precaution, a boil-water advisory was issued Tuesday night. Officials lifted the advisory for a small area on the west bank of the Mississippi River on Thursday. But test results showed possible contamination on the east bank where the advisory remained in effect for the majority of the city’s nearly 370,000 people.

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Does this happen often?

It happens often enough that many utility companies have been taking note for years.

“They are a very big hazard to our system,” said Shelton Hudson, director of reliability for Entergy. “Typically in the seasons of folks having graduations and birthdays and different things like that.”

St. Louis-based Ameren Corporation, which provides electrical service in Illinois and Missouri, said there were 582 balloon-related outages nationwide last year, affecting 800,000 customers. Public Service Electric & Gas, New Jersey’s largest utility, reported in 2020 that it had experienced a 26% increase in outages caused by Mylar balloons over a five-year period.

Entergy and other utilities have safety tips on their websites that include keeping Mylar balloons indoors, tying them down with weights or anchoring them to secure objects and deflating and disposing of them once the celebration is over.

Other concerns

Utility lines aren’t the only worry. Environmentalists and the U.S. Fish and Wildlife Service say balloon remnants are a hazard to wildlife. Birds, turtles and other animals sometimes try to eat the remnants, causing injury or death, according to the USFWS.

Remedies

Some communities have gone so far as to ban balloon releases. Galveston, Texas, for instance, outlawed outdoor balloon releases in 2021, Texas news outlets reported. But there has been pushback from business interests. The Balloon Council, an industry group, says on its website that it endorses a California law passed in 1990 that regulates helium-filled Mylar balloons. But the group has been critical of other laws in recent years that it says have been too restrictive and harmful to business.