Data centers have dominated headlines and social feeds lately. In a four-part series, WVXU is delving into some of the issues surrounding them. For this story, WVXU talked to experts, watched testimony before state lawmakers, and reviewed research to explore some of the environmental issues around data facilities.
The rapid pace of large, new data center projects proposed or breaking ground in Ohio, Kentucky and Indiana has sparked a lot of anxiety among some people about how they will affect the natural world.
Ted Smith is an environmental health researcher at the University of Louisville. He says much of a data center’s environmental impact depends on where it is sited, the kind of cooling system it uses, where it gets its power from, and a number of other complex factors.
He says data centers can bring economic benefits but also anxiety, especially as there's a dearth of epidemiological research on the health effects of emissions, noise, water quality and more.
"Everything is moving so fast, we’re asking people to work without the evidence. And that can be really uncomfortable. I don’t know what the health effects are of living next a hyperscale data center. Unfortunately, I don’t know anyone who knows the effects of living next to a hyperscale data center," he says.
Ohio State University Sustainability Institute Associate Research Director Jeff Bielicki suggests using some of the computing power data centers make possible to study their effects on human health and the environment.
“When we think about data centers, we need to try to find a middle road, and increasingly put more effort into using the capacity of the AI enabled by the data centers to help address environmental and human health problems — [such as] new materials discovery, new innovation on energy technologies, new understandings of pathways of respiratory disease, and so on,” he said.
The region’s data center boom
Ohio has more than 200 planned or existing data centers, according to the Ohio Consumers’ Council. The governmental organization says that puts Ohio fifth in the nation for its concentration of the tech facilities.
The Columbus area — driven by the suburb of New Albany — leads the state in the number of data centers, followed by Greater Cincinnati and the Cleveland area, according to Data Center Map, a website that tracks data centers for companies looking to buy or sell computing power.
Kentucky has fewer data centers — around 60 — mostly clustered around Louisville, and Indiana has about 125, almost all of them around Indianapolis and South Bend.
In all three states, data centers range from small sites with negligible electricity and water usage to extremely large facilities. More of the large sites are coming, including a 10-gigawatt data campus in Pike County, Ohio, being developed by the U.S. government and Japanese tech firm, SoftBank.
When all phases of that facility are finished, it will be significantly larger than the current median 100 megawatt capacity of a data center in Ohio. It could become one of the largest data centers in the country.
About $55 billion in data center projects are proposed or underway in Ohio currently, according to research by Industrial Information Resources, a publication that tracks data center and energy development. That number will continue to grow, representatives for the industry say.
“We are likely still at the early stages,” Data Center Coalition (DCC) Vice President for State Policy Dan Diorio told the Ohio House and Senate Select Committee on Data Centers earlier this year. DCC is the trade association for companies that develop data centers, including Amazon, Google, Meta and more than three dozen others.
“There is still significant development to go as we see continuous projects seek to develop in the state,” he said.
Diorio says the increase is driven by demand for computational power — from credit card processing to data storage on the cloud to geolocation and AI.
Diorio says smaller data centers date back to the late 1990s. The current increase in hyperscale (more than 50 megawatts) data centers started in about 2020. That’s kicked off a big increase in demand for power.
Energy
According to the Ohio Consumers’ Council, data centers across the U.S. used about 176 terawatt hours of electricity in 2023. That's about the same amount the entire state of Ohio used that year, and about 4% of all the electricity used in the U.S. That share is expected to increase to 9% by 2030.
The production, movement and sale of electricity is accomplished via a complex network of agencies, power providers and transmission infrastructure. PJM Interconnection is a nonprofit that manages the transmission and wholesale market for electricity across 13 states and the District of Columbia, including Ohio and parts of Kentucky and Indiana. That role makes the Pennsylvania-based organization well-situated to track the impact of data centers on electricity usage.
The organization recently said the data center boom has been “the primary driver” of growth in demand for electricity. That, in turn, has driven up prices for consumers, according to the Ohio Consumers’ Council.
PJM Executive Vice President of Governmental and Member Services Asim Haque told Ohio lawmakers earlier this year that the organization has seen a “generational increase in demand” both in the present, and in projections for the future.
“Hyperscalers can range from 50 megawatts to 10 gigawatts down in Portsmouth,” Haque said, referring to the Pike County project. “A hyperscaler that is 50 or 100 megawatts, you’re looking at the size of Mansfield. A gigawatt, if you go to the New Albany data center campus for Meta, that is the size of Cleveland in terms of their consumption.”
Right now, all that extra demand hasn’t outrun supply in the region. Last year, PJM managed about 185,000 megawatts of power across its network. So far in 2026, peak power demand has been about 156,000 megawatts.
In 15 years, however, PJM predicts peak demand will reach more than 220,000 megawatts, well beyond the grid’s current capabilities.
Diorio, with the data center trade group, says the centers are responsible for roughly 50% of the increase in power demand across PJM’s network.
Haque said the main concerns with the spike in power demand are reliable energy supply and price increases for consumers — issues that state lawmakers, PJM and the Public Utilities Commission of Ohio are trying to iron out.
Haque and some policy makers believe the best path is to push data centers to supply their own power “behind the meter,” meaning they wouldn't be reliant on the existing energy supply.
Air quality
Bielicki says air pollution caused by fossil fuel power plants providing electricity to data centers can cause respiratory illnesses and contributes to global warming.
“The emissions from the power plants and generators providing electricity are not inconsequential,” Bielicki says. “They have known effects on the environment, known effects on human health. That’s well understood, from local, regional, national to international communities.”
Emissions from fossil fuel power plants contribute to global warming and are linked to higher rates of illnesses from asthma to lung cancer.
A report earlier this year by Ohio University’s Voinovich School of Leadership and Public Service cites modeling suggesting the average data center in the state is responsible for 39.2 million kilograms of greenhouse gas emissions annually. For context, Ohio emitted roughly 186 billion kilograms of greenhouse gases in 2024, according to the U.S. Energy Information Administration.
How much future data centers add to those emissions depends on what kind of power they will rely on.
Haque says PJM currently has greenlit about 10 gigawatts of new power production projects in Ohio and is studying proposals for another 3.7 gigawatts. More than 80 of those proposed projects are solar power, while only 12 are gas-powered.
It’s unclear how large individual projects are and how much power each will generate. Haque told lawmakers only about 10% of proposals the organization fields end up as actual power plants, and that renewable energy like solar and wind has an even lower batting average.
Right now, OSU’s Bielicki says, the Buckeye State relies mostly on power that emits greenhouse gases.
“In Ohio, about 80% of the way we generate electricity for our economy is undermining the environment upon which our well-being depends,” Bielicki says. “Well-being is not just economic well-being. It’s also health and environmental well-being.”
Backup diesel or natural gas-powered generators data centers have onsite in case their main power source temporarily fails are another concern for air quality. Centers often test those generators monthly.
“We’ve heard the horror stories about big diesel generators and gas turbines, things that are polluting and noisy,” says Smith, the U of L researcher. “But there are alternatives that are now coming onto market like battery backup systems are quiet and don’t have emissions.”
It’s not entirely clear which direction the scales will tip. There have been proposals to recommission older coal-fired or gas power plants to fill the nation’s energy gaps — in part created by the upsurge in data centers — which would increase greenhouse gas emissions.
“We do see advanced developments of data centers using mixtures of technologies, experimenting with hydrogen cells. There’s a big push now for small nuclear,” says Smith.
Nuclear power is one possibility floated for the large Pike County site. It brings its own environmental questions, from disposal of nuclear waste to fears of radiation exposure, especially in a community that has dealt with grave health concerns involving radiation in the past. However, experts point out that nuclear power emits almost no greenhouse gases.
Water usage
Historically, data centers have used large amounts of water to cool electrical components, which heat up as data processing occurs. The report by OU’s Voinovich School identifies water usage as the most significant local environmental concern for individual data facilities.
“A single large Ohio facility draws on the order of 2.7 billion kilograms of water per year — comparable to the annual water use of roughly 24,500 people,” the report states. “Aggregated across the state's roughly 205 facilities, collective withdrawals are on the order of the annual water use of about 5 million people, though this comparison includes indirect water embedded in electricity generation.”
Water usage is a huge question for groups like the Miami Conservancy District (MCD). The century-old organization is charged with stewardship of the 10-county watershed in Southwest Ohio, including the Great Miami Buried Valley Aquifer. The underground water source stretches from just north of Dayton to the Ohio River and provides water for millions in Southwest Ohio.
“There is no reasonable alternative if the aquifer is no longer available, either by degradation of quality or loss or misuse of the quantity,” MCD Director of Communication, Outreach and Stewardship Sarah Hippensteel Hall told lawmakers earlier this year. “This resource has supported our region for generations. It is our greatest regional asset. It is also a resource that requires careful stewardship. We have a lot of water, but only if we use it properly.”
Hall says there is a lot to consider when it comes data centers and their water usage:
- projected water demand from centers
- impact on groundwater and aquifers
- the effects of wastewater discharge
- what could happen if multiple large volume water users are built in the same watershed
- water-usage efficiencies
- using other cooling technologies to conserve water.
Data centers can also release a lot of water back into the surrounding landscape or water system, sometimes at temperatures many worry are disruptive to ecosystems.
Hall says the MCD is currently conducting a study of the vulnerability of the Great Miami Buried Valley Aquifer.
The Ohio EPA, the Ohio Department of Natural Resources and the Ohio Water Development Authority are also conducting a study of Southwestern Ohio’s water resources. It follows a similar, recently completed study looking into water availability in central Ohio, as large developments like a new Intel facility and dozens of data centers spring up there.
The study will use water data, population growth forecasts and other information to model how much water the 20-county region will have in coming years.
“[Water is] something that the industry takes very, very seriously,” Diorio, with the data center trade group says. “The technology is moving at a rapid pace and it’s achieving significant efficiencies.”
Newer data centers are moving toward hybrid systems that use air to keep equipment cool during cooler months in colder climates, he says. Some data centers also use closed-loop systems, in which water is recycled through the same system over and over again; or immersion systems, where processing equipment is stored in a liquid cooling solution, cutting down on both water consumption and wastewater release.
These conserve water, but at a trade-off. Generally, the less water a system uses, the more electricity it will use instead. That can circle back around to water usage.
“One of the factors there is that the majority of the water use isn’t actually at the data center, it’s at the power plant providing the electricity,” Bielicki says. “If it’s a coal, natural gas or nuclear plant, it needs to be cooled. Actually, water use for the electricity is about 80% of the water demand for a data center.”
Global issues, local details
Hall, with the Conservancy District, says communities and planners should consider water at the very beginning of the decision-making process about data centers, and should keep in mind the long-term implications of their decisions on water sources like the Great Miami Buried Valley Aquifer.
“Understanding local conditions is extremely important,” Hall said. “A one-size-fits-all approach across Ohio will not fully reflect the differences between sites, watersheds or water resources. We see what happens other places when water is an afterthought.”
The balance between economic growth, broad environmental impacts and the effect on local communities is a delicate one, experts say.
Smith, the University of Louisville researcher, says it’s important communities are able to weigh the costs and benefits and have a say in how they are built.
“We need good design requirements for the kinds of facilities we’re building and we need buy-in that they’re not going to be negatively impacting the populations that live there from a health perspective,” he said.
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