Large data centers are being proposed and built across the Great Lakes region, including Illinois. Without comprehensive protective planning, pollution prevention, and water use reporting, they could irreversibly drain huge amounts of water that Illinoisans rely on every day for drinking water, agriculture, and business purposes. Without stronger guardrails, they could expel wastewater that’s contaminated with pollutants, putting local communities at risk and damaging our lakes and rivers.
Illinois communities are raising concerns about the pace and lack of transparency as data center plans rapidly expand across the state. In fact, a recent poll of Illinois voters found that 96% agreed that the state should “ensure data centers pay their fair share of water infrastructure costs,” while 92% support requiring “an analysis that a data center won’t increase harmful health, water, and environmental impacts on vulnerable communities before a project moves forward.”
The Alliance for the Great Lakes supports the POWER Act, an Illinois bill that establishes transparent reporting and consumer protection requirements for data centers to help ensure Illinois’ water resources are used responsibly.
At a recent hearing on the bill, Helena Volzer, Senior Source Water Policy Manager, testified about data centers’ water impacts and how the POWER Act would support sustainable growth while ensuring thoughtful stewardship of Illinois’ water.
The testimony below was submitted to the Illinois House Executive Committee on SB4016/HB5513, the POWER Act, on April 22, 2026, on behalf of the Alliance for the Great Lakes:
Chairperson Ann M Williams, Vice Chairman Robert Rita, Republican Spokesperson Ryan Spain, and esteemed members of the House Executive Committee, my name is Helena Volzer, and I am the Senior Source Water Policy Manager at the Alliance for the Great Lakes. On behalf of the Alliance, thank you for the opportunity to provide subject matter testimony on data center impacts and in support of SB4016/HB5513, the POWER Act. For over fifty years, the Alliance for the Great Lakes has been working to protect our region’s most precious resource: the fresh, clean, natural waters of the Great Lakes for today and generations to come.
We would like to thank Majority Leader Robyn Gabel and Senator Ram Villivalam for sponsoring this critically important legislation SB4016/HB5513, the POWER Act, will establish a framework and common-sense guardrails that will support sustainable growth while ensuring thoughtful stewardship of Illinois water, transparency, accountability, and protection for communities and ecosystems from water overuse and preventable pollution. The Alliance for the Great Lakes urges support and the swift passage of the POWER Act as a critical and timely framework to address quickly evolving challenges and protect our region’s water for generations to come.
As you may know, the Great Lakes are a globally significant, finite, and precious resource. They hold 22% of the world’s fresh surface water and provide drinking water to over 40 million people in the US and Canada. Perhaps less well known is the Lakes’ essential connection to groundwater. Between 20 and 40% of the water flowing into and out of the Great Lakes system originates as groundwater. In Illinois, 40% of residents rely on groundwater for their drinking water.
Yet as I speak, groundwater is becoming increasingly vulnerable to overextraction, especially during peak summer months that are growing hotter and drier due to climate change. The connection between groundwater and surface water means surface water resources can become stressed if groundwater becomes depleted. With simultaneously competing demand for water from agriculture, industry, data centers, and residential use, communities in Illinois are facing complex trade-offs in managing finite water supplies.
Nevertheless, large water users such as data centers are being proposed and sited in Illinois before there has been any comprehensive evaluation of whether the watershed can handle it. Currently, factors such as groundwater recharge rates, whether existing supplies can meet demand, including the data center’s water use at peak capacity, potential impacts to ratepayers, and the cumulative effects of increased water use are not being factored into the decision-making process and they should be.
What happens when water supplies aren’t sustainably and responsibly managed?
- Conflict. Increased water stress creates potential for intensified groundwater conflicts that Illinois’ groundwater law is currently ill-equipped to resolve.
- Ecosystem impacts. When groundwater is pumped out faster than it can recharge, water levels drop. This can cause wells to run dry, reduce flow to streams, and degrade wetlands.
- Increased costs. Increased water scarcity means increased costs; if well owners or water systems have to drill deeper, they incur not only additional expense; it risks contaminating aquifers. Drilling deeper may not even be an option if the aquifer is depleted – potentially necessitating a costly connection to another water system that can supply water. Furthermore, if water systems aren’t prepared to handle data centers at their peak capacity, it can cause drops in water pressure for customers and lead to water main breaks- introducing additional contamination to the system that must be treated for. All of these costs could easily trickle down to water and wastewater ratepayers.
- Unsafe polluted water: Illinois regulations are not designed to sufficiently monitor and regulate pollutants in data center wastewater discharge. After decades of remediating Illinois waterways from the last centuries’ industrial pollution, it is critical to prevent any future pollution at the source. We simply don’t know enough about the contents of data center wastewater discharge and there is a need for more comprehensive monitoring and effluent limitations to safeguard water quality.
- Increased pressure on the Great Lakes system. When groundwater levels decline, so does the natural flow to our streams, rivers, and lakes. Over time, that cumulative pressure increases – ultimately causing communities to have to look elsewhere for water. We can already see this happening as Joliet and neighboring communities turn to Lake Michigan for water.
How does the POWER Act help? The POWER Act helps establish a framework for more sustainable data center water use. It does so by creating transparent water use reporting, a permitting system to manage water resources sustainably and accountably to reduce the potential for groundwater conflict, and consumer protection requirements to ensure that data centers pay their fair share of water and wastewater infrastructure.
Technology changes quickly – just a few years ago, we had no AI and no hyperscale data centers. But right now, the Great Lakes region hosts nearly one-fifth of all U.S. data centers, with growth expected to exceed national averages through the end of the decade. Illinois needs a state-level framework that adapts to the times and provides a comprehensive way to ensure water is available right now and for future generations. Consistent rules that monitor water use, ensure transparency, and prevent pollution are necessary to equip the state with the tools it needs to make sure that clean, fresh, water is available for all. Because if there is no clean safe water, there won’t be any data centers or economic development either.
Protecting the Great Lakes requires aligning economic development strategies with hydrologic reality and preventing future pollution. The POWER Act provides a critically important framework that supports sustainable growth by ensuring managed water use, transparency, accountability, and protection for communities and ecosystems from preventable pollution or water overuse.
The POWER Act establishes an evidence-based regulatory framework and a long-term planning approach that helps prevent the disastrous consequences of unsustainable water use. At the same time, we recognize the challenging and multifaceted nature of this issue and stand ready to work with all interested parties and levels of government to ensure we build a framework that can both adapt to the rapidly changing economic landscape while preventing irreversible adverse water resource impacts.
We again wish to thank Majority Leader Robyn Gabel and Senator Ram Villivalam for protecting our state’s precious water resources and introducing this bill and thank you to the Chair and the committee for allowing us to provide testimony today.