Some groups have raised concerns that per- and polyfluoroalkyl substances, or PFAS, may be used in the cooling process and later flushed into wastewater systems. Exposure to some "forever chemicals" has been linked with serious conditions, including certain reproductive health issues.
Job creation, land use, the vast amount of energy required to run the data centers that power artificial intelligence, and a multidimensional look at the water use behind AI were just some of the topics tackled at a Milwaukee, Wisconsin, town hall on the technology. More than $46 billion in data center developments have been proposed or are under construction in the state, according to the event's host, the Milwaukee Journal Sentinel.
On the topic of water used to cool the data center infrastructure that heats up when in operation, reporter Caitlin Looby noted in a prerecorded video that the "data centers currently proposed use closed-loop systems, a kind of cooling system where water circulates through the system over and over." This newer cooling system ostensibly reduces overall water usage, though some water may still be lost to evaporation and leaks.
Yet, it's noteworthy for those concerned about potential water contamination that some environmental groups have raised the concern that per- and polyfluoroalkyl substances, or PFAS, may be used in the cooling process and ultimately flushed into wastewater systems.
Exposure to this class of synthetic chemicals, commonly known as "forever chemicals" for their persistence in human bodies and natural habitats, has been linked to serious health conditions. These include certain cancers, decreased fertility, and higher blood pressure in pregnant people, according to the U.S. Environmental Protection Agency.
"If the water discharged to a wastewater treatment plant contained any chemical, like a coolant, that information would have to be disclosed to the wastewater treatment plant so it can be treated," Looby explained at the town hall. But the reporter went on to note that most treatment plants can't remove PFAS, which have been found in drinking water around the world. Experts suspect that much of the existing PFAS water contamination may be traced to agricultural and industrial sources.
In response to a question regarding myths about data centers, Melissa Scanlan — the Director at the Center for Water Policy at the University of Wisconsin, Milwaukee — noted what she's heard about closed-loop cooling systems.
"Last week, I heard a representative from Loudoun Water in Virginia," Scanlan said at the Milwaukee event. "They accept wastewater from almost 200 data centers. … they have received slugs of chemicals that they did not expect, and they've had to scramble to respond. So now they require chemical analysis of the wastewater at every data center before it is discharged to their system, to the municipal wastewater treatment system, because of that experience."
Proponents of AI note that numerous applications of the technology — improving energy efficiency, refining disease diagnosis, strengthening food security and extreme weather warnings — may have the potential to improve lives. But many are also pushing for regulations to protect the energy grid, water resources, and the public.
"First and foremost, you need transparency and disclosures of data in order to even entertain the thought of a scientific analysis," Scanlan said, noting that early in her team's research at the Center for Water Policy, much of the information researchers had to go on was from investigative journalists rather than scientists or the data center operators themselves.
"We really think that what's needed here is legislation that requires a cumulative impact analysis of all the existing and proposed data centers in the state and ideally for a regional area," Scanlan continued, arguing for an analysis that factored in not only water usage and treatment but also potential air pollution, energy usage, utility rates, potential job creation, and more.
Data centers have become a hot topic in the lead-up to the 2026 midterm elections in the U.S., where voters across the political spectrum have been pressing candidates at the local, state, and federal levels to speak to potential reforms with clarity.
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Keya Khandaker of Plan International told CG about the research documenting the lives of girls in Benin, Brazil, Cambodia, the Dominican Republic, El Salvador, the Philippines, Togo, Uganda, and Vietnam.
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