Immunologist Boris Donsky explained whether it is safe to drink water after prolonged power outages

After prolonged water service interruptions, tap water may change color and develop an unpleasant odor due to its prolonged stay in the pipes. At the same time, the water’s clarity and the absence of an unusual odor do not guarantee its safety.

Immunologist Boris Donsky explained why it’s important to let the water run for a while after the water supply is restored, whether boiling helps remove contaminants, and whether you can test water quality on your own.

According to the doctor, water quality depends on the amount of impurities that may enter the water either at the intake stage or while it flows through the pipes. After sitting in the water supply system for a long time, its condition can deteriorate, particularly due to contact with sediment and rust.

“There are certain standards regarding what substances water may contain, and levels exceeding these limits are considered hazardous to health. As you can see, this is a matter of quantity—the purer the water, the better it is. Certain impurities are added to the water; it picks them up as it flows through the water system,” explained Boris Donsky.

The immunologist noted that after water outages, the water can take on a distinctive color and odor due to contact with the inner surfaces of the pipes. Therefore, once the water supply is restored, it is important to pay attention to its appearance and not to use water with obvious signs of contamination.

“Have you often noticed this after a water outage—even one lasting just a few hours—where you turn on the faucet and rusty water comes out? This happens because a pocket of air has passed through the pipes; the water has sat in them, picked up this rust, and needs to be flushed out at first. If the water has been sitting in the pipes for an even longer period, it may become even less clean and more contaminated,” the expert said.

Therefore, after the water supply is restored, you should let it run out if it has an unusual color or other signs of contamination. At the same time, draining the water does not in itself guarantee its safety if the contamination is of a different nature.

Boris Donsky noted that the risk of infection through intact skin is not the same as when consuming contaminated water. However, during hygiene routines, water can enter the mouth, eyes, or mucous membranes. Therefore, if contamination is suspected, it’s best not to use it for brushing teeth or other procedures during which water can enter the body.

“I don’t think it can be contaminated enough to pose a risk through the skin. But if the water sits in the pipes and plumbing for a week, it’s possible that it will contain more harmful microorganisms and be more heavily contaminated,” the immunologist noted.

At the same time, boiling helps disinfect water and destroy many pathogenic microorganisms, but it does not eliminate all possible contaminants. In particular, it does not make water safe if it contains excessive amounts of heavy metals or other chemical impurities.

“Boiling disinfects water. But if the water is also rusty and has a high concentration of heavy metals, then whether you boil it or not, it will still remain contaminated. That’s why it’s worth at least running it through household filters,” explained Boris Donsky.

It’s important to note that household filters have varying capabilities: their effectiveness depends on the type of filter and the specific contaminants. Therefore, filtration is not a universal guarantee of water safety either.

According to Boris Donsky, it is impossible to determine whether water is safe based solely on its color, smell, and taste. Even clear water with no noticeable odor may contain substances that cannot be detected without specialized testing.

“You can determine on your own that the water is unfit for consumption. But you shouldn’t try to determine on your own that it’s definitely safe to drink, because you don’t have the means to do so. There are agencies in charge of this; they’re supposed to regularly test water quality. And we hope they’re doing so,” said the immunologist.

Therefore, if the water has an unusual color, odor, or other signs of contamination after the water supply is restored, you should not drink it until the cause is determined. Appropriate tests are required to assess water quality, and if you have any doubts about the safety of the water, you should follow the announcements from local water utilities and the recommendations of health authorities.

The immunologist also cautioned against attempting to determine on one’s own the cause of feeling unwell after coming into contact with potentially contaminated water. Symptoms depend on the nature of the contamination: microorganisms can cause intestinal infections, while chemicals can cause other health issues.

“You shouldn’t try to diagnose yourself. Any deterioration in your health may indicate that something has entered your system. If the water is contaminated with microorganisms, it will result in intestinal infections. If it contains heavy metals, the symptoms will be completely different,” the expert emphasized.

According to Boris Donsky, some toxic effects may not manifest immediately but rather as certain substances accumulate in the body. Therefore, you shouldn’t judge the safety of water based solely on how you feel.

If unusual symptoms develop after coming into contact with suspicious water, you should see a doctor.

In Kyiv, utility workers have stabilized the power supply situation following a massive Russian attack. On Thursday, October 15, rolling blackouts resumed in the capital. 

As a result of a massive nighttime Russian strike on critical infrastructure in Kyiv, the Kyiv region, and Kharkiv, at least 600,000 consumers were left without power. Ukrainian President Volodymyr Zelenskyy reported that the attack damaged 26 power facilities and four oil and gas facilities.

As a result of the Russian attack, parts of Rivne and the Rivne district were left without power. Information regarding the extent of the power outages and the causes of the damage to the energy infrastructure has not yet been specified.