Residents of St. Petersburg – on Florida’s central west coast – were temporarily without clean drinking water after a water main break occurred during Hurricane Milton.

City officials said the outage caused them to shut off drinking water supplies at noon ET Thursday until repairs could be made.

“Residents and businesses should prepare for this temporary closure, which is expected to last until necessary repairs can be completed,” the city said in a press release.

“Water line repairs will begin as soon as it is safe for crews to be outdoors. The affected areas may already experience low water pressure or service interruptions,” the statement continues.

On Thursday afternoon, officials said drinking water supplies were back but pressure may be low.

In addition, officials said a helicopter from the sheriff’s office in Pinellas County, where St. Petersburg is located, helped search for water leaks in the main.

Typically, water distribution systems are under sufficient pressure to prevent dirty water and contaminants from entering, even if there are cracks. However, when a water pipe breaks, system pressure drops and pathogens can enter.

“If the water main breaks, we can see water leaking and think, ‘Oh, we’re losing water.’ But what’s happening in other areas of the system is that the pressure is easing,” said Dr. Sandra McLellan, a distinguished professor at the University of Wisconsin-Milwaukee’s School of Freshwater Sciences, told ABC News.

“Whatever is in the soil can seep into the pipes. … If there’s a water main break and there’s a lot of flooding or a lot of storm water, then all that wastewater that’s around those pipes and in the ground can seep into our drinking water systems,” she continued.

Some of the contaminants may be visible to the naked eye and may simply cause discoloration or cloudy water. Other containments may not be visible and can lead to serious illnesses such as E. coli or norovirus.

McLellan said people may not realize their drinking water is contaminated until they experience symptoms of illness.

“There is no real way to easily test the water for pathogens because the concentration is rather low,” she said. “So it’s not like everyone is going to get sick, but if 100 people drink the water, there’s a good chance that one or two people are drinking some of the water that contains these pathogens.”

Dr. Norman Beatty, an assistant professor of medicine at the University of Florida College of Medicine and an infectious disease physician, told ABC News that ingesting bacteria found in storm surge water can cause diarrheal illness, but can also lead to sepsis in some Hospitalization.”

The city has issued a boil water advisory for drinking, cooking and brushing teeth, saying it will remain in place during repairs.

Beatty recommends using bottled water until the water is safe to drink, or boiling water.

“When boiling water, start the timer once you reach a steep boil and allow the water to cool naturally after a minute. If the water is cloudy, let it settle and then filter it through a clean coffee filter paper or cloth,” he said.

McLellan said after a main break, crews would dig up the road, repair pipes and restore pressure. She added that clean drinking water should be restored after pressure is restored by flushing the pipes.

If people are concerned about their water supply, she recommends using a pitcher with a household water filter before drinking tap water.

“I think people think, ‘Oh, if my water is turned off, of course there’s a problem. But if my water is connected, the water is safe,'” she said. “But we really have to keep in mind that in areas where there are hurricanes there is definitely potential for damage, so it’s better to be on the safe side.”

On Wednesday evening, St. Petersburg officials also shut off power to two wastewater treatment plants in the northeast and southwest of the city to protect employees and facilities from possible storm surges.

By Thursday morning, sewer lines were back online and city crews were en route to inspect and restore power to both power plants.

Hurricane Milton made landfall on the west coast of Florida on Wednesday evening as a Category 3 hurricane.

Gov. Ron DeSantis said Thursday morning that the hurricane had “fortunately” saved the state from the “worst-case scenario,” but that flooding is expected to continue for the next few days.