September 28, 2026

Deconstructing Data Centers: Air, Water, And Noise Concerns

Deconstructing Data Centers breaks down the often complex legal, energy, regulatory, and political issues associated with data centers.

By Tom McFeeley, Media Relations Specialist

In an earlier post we mentioned that data centers need “a lot of electricity, and a lot of water, to keep running.” In this post, we are  stopping to actually explain that sentence, because for the communities living closest to a new data center, water, air quality, and noise are often the very first concerns people raise, long before anyone starts talking about electricity bills or clean energy policy.

WHY DATA CENTERS NEED SO MUCH WATER

All those servers packed into a data center generate an enormous amount of heat, and heat has to go somewhere. Many data centers rely on evaporative cooling, essentially large-scale versions of a swamp cooler, an old-fashioned cooling device, common in hot, dry climates, that pulls warm air through water-soaked pads so the water can evaporate and carry the heat away with it, the same reason sweat cools your skin. It works well and it’s relatively cheap. It also uses a lot of water, and most of it doesn’t come back.

The numbers vary a lot depending on size and climate, but they add up fast. A medium-sized data center can use around 300,000 gallons of water a day, roughly what 1,000 households use. A large, hyperscale data center can use up to 5 million gallons a day, enough to match the daily water use of a small town of 10,000 to 50,000 people. And because evaporative cooling works by letting water evaporate into the air, up to 85% of the water a data center draws never returns to the local water supply at all.

That matters most in places already under water stress, but it’s worth remembering even here in the Midwest, where a single new hyperscale project can still represent a significant new draw on a local water system that residents, farms, and other businesses already depend on.

THE AIR QUALITY PROBLEM HIDING IN PLAIN SIGHT

Water isn’t the only environmental concern. Nearly every data center also keeps a fleet of diesel backup generators on-site, meant to kick in if the power ever goes out. They’re supposed to run rarely, mostly for testing. But even limited use adds up, and diesel exhaust contains a fine particulate matter and nitrogen oxides that are linked to asthma, heart disease, and other serious health problems.

Here’s the number that tends to stop people: industrial diesel generators can emit 200 to 600 times more nitrogen oxides than a natural gas plant producing the same amount of power. One analysis in Virginia, home to the country’s largest concentration of data centers, found that even limited backup generator use across the region could be associated with nearly $300 million a year in public health costs and roughly 14,000 asthma-related health impacts.

This isn’t just a Virginia problem. In Hilliard, Ohio, residents raised the same alarm this year after a proposed Amazon data center project included plans for 158 diesel backup generators. A February 2026 health impact report on the project concluded that the emissions could contribute to breathing problems and premature deaths for nearby residents, findings that one Hilliard resident brought directly to state regulators, testifying that the safety of this kind of facility, sited next to a neighborhood and an elementary school, simply hadn’t been studied enough. That’s not a hypothetical concern. That’s a resident showing up to a real siting hearing with a real question that, right now, doesn’t have a real answer.

THE NOISE THAT DOESN’T STOP

Water and air are only part of what neighbors notice first. Data centers run their cooling systems and backup power around the clock, and the result is a constant industrial hum that doesn’t let up at night, on weekends, or ever. Unlike a passing truck or a lawnmower, it’s there when residents wake up, and it’s still there when they go to bed.

This isn’t a hypothetical for the Midwest either. In Dowagiac, Michigan, residents living across from a data center say the noise runs between 50 and 62 decibels around the clock, spiking as high as 84 decibels, loud enough to compare to a passing jet or a running vacuum. More than 1,300 nearby households are now part of a federal class-action lawsuit, with residents describing sleepless nights and an inability to sit outside or open their windows.

Part of the problem is that most local noise ordinances were written for block parties and barking dogs, not a facility that runs 24/7, and low-frequency industrial hum is often hard to capture on a standard decibel meter even when it’s loud enough to disrupt sleep. In Virginia, home to the country’s largest concentration of data centers, nearly a third of them sit within 200 feet of a home, because zoning rules often treat data centers the same as an ordinary office building rather than an industrial facility.

THE CONNECTION BACK TO CLEAN ENERGY

Wind, solar, and battery storage don’t need diesel backup generators running emergency tests, and they don’t pull millions of gallons from a local water system to stay cool. Solar and battery storage don’t hum the way fossil-fueled backup power does, and even wind, which has a noise profile of its own from the blades, produces sound far below what a diesel generator or gas turbine running around the clock puts out. When we say data centers should be required to bring new clean energy, we’re not only talking about who pays for the grid. We’re talking about what actually gets built next door to a neighborhood, and what that neighborhood breathes, drinks, and hears as a result.

That doesn’t mean every data center powered by clean energy is silent or uses zero water, servers still generate heat and noise that has to go somewhere. But it does mean the harshest costs, diesel exhaust, heavy water withdrawal, and around-the-clock industrial noise tied to fossil-fueled backup power, aren’t inevitable. They’re a choice being made in how these facilities get built and permitted, which means they’re also a choice regulators and lawmakers can change.