Demand for cloud services and AI continues to drive new data center builds, including hyperscale sites capable of reaching 50 to 200 megawatts or more. Meanwhile, more communities are pushing back. Two concerns show up most often. Water use. Water quality.
Do these concerns have merit? Yes. In many locations, a large data center can materially affect local water demand, and some cooling systems generate wastewater streams that require careful controls. The key is variability. Water outcomes vary by cooling design, climate, and the water source used by a facility.
Why Data Centers Use Water
Servers turn electricity into heat. Operators must remove that heat from the building every hour of every day. Many facilities rely on cooling towers or other evaporative systems because they reduce the electricity used for cooling. Evaporation consumes water. That is different from withdrawing water and returning most of it to a river or aquifer. The U.S. Department of Energy highlights Water Usage Effectiveness (WUE) as a way to track water use relative to IT energy use. The Green Grid introduced WUE as a standard metric for the industry.
How Much Water Are We Talking About
Public estimates vary widely. The Environmental and Energy Study Institute reports that a medium-sized data center can consume up to about 110 million gallons of water per year for cooling, and that very large facilities can reach up to 5 million gallons per day in some cases.
Those “mega” numbers are not typical across every site. Uptime Institute’s analysis of survey data reports that only 14 percent of respondents with water-cooled data centers used more than 16 million gallons per year. That reflects a reality that communities feel on the ground. A few large projects can dominate local concern, even when the industry average looks smaller.
Direct Water And Indirect Water
Community debate often focuses on the water piped to the site, but the water footprint can extend upstream. Bluefield Research estimates that in 2025, U.S. data centers directly withdrew about 107 million gallons per day and consumed about 60 percent of that, largely through evaporative cooling.
Electricity has a water footprint, too. DOE’s best practice guide describes a “source-based” WUE that includes off-site water used to generate the on-site energy. In grids that rely on water-intensive generation, a design choice that saves direct water by using more mechanical cooling can shift water impacts upstream.
What About Water Pollution
Three pathways drive most of the water quality discussion.
Cooling tower blowdown: In a cooling tower, water evaporates, but dissolved solids stay behind. Operators discharge a portion of the circulating water, called blowdown, to control mineral buildup. Technical references describe blowdown streams with elevated total dissolved solids, treatment chemicals such as biocides and corrosion inhibitors, and metals from corrosion.
Glycol leaks and disposal from closed-loop systems: Many data centers use a glycol and water mix in closed loops for freeze protection, especially in outdoor piping, dry coolers, and some liquid cooling loops. These loops are designed to stay sealed, so glycol is not supposed to discharge during normal operation. This method reduces water runoff. However, it raises community concerns about accidental release.
Both ethylene glycol and propylene glycol can create high oxygen demand if they reach surface waters, thereby lowering dissolved oxygen and harming aquatic life. Ethylene glycol also carries higher toxicity concerns, so some operators prefer propylene glycol where feasible. When systems are drained during maintenance or decommissioning, an ITAD provider can coordinate documented, compliant removal of spent glycol and related cooling hardware through licensed recyclers or hazardous waste partners.
Discharge route and permitting: Many facilities discharge blowdown to a sanitary sewer and a publicly owned treatment works. Local pretreatment programs can set discharge policies and best practices to protect the wastewater plant. Jacksonville Electric Authority’s pretreatment program is an example of a published cooling-tower blowdown policy for sewer discharges. If blowdown discharges to surface waters, Clean Water Act permits can apply. EPA permit fact sheets list pollutant limits for cooling-related discharges, including total residual chlorine.
So, is “water pollution” a fair concern? The concern is real. The risk is usually managed through standard treatment and permitting, not ignored. The bigger local question is capacity. A large new blowdown stream can strain a small wastewater plant, especially if salinity or treatment chemicals approach the plant’s limits.
Why Pushback Is Growing
Growth is fast, and many projects cluster in the same corridors. That creates cumulative demand. Recent reporting has highlighted rising community concern across several U.S. regions, including Texas.
Water stress is also part of the story. A Houston Advanced Research Center analysis, reported by the Houston Chronicle, projects that Texas data center water use will rise sharply by 2030 and frames it as a planning gap in existing water forecasts.
Disclosure remains inconsistent. Bluefield Research argues that limited transparency into data center water use makes community planning more difficult and fuels mistrust.
What Responsible Developers Are Doing
Communities are not only asking “how much water” but also “what kind of water” and “what happens after use.” There are practical steps that reduce risk.
Cooling design choices: Hybrid approaches can reduce water use during hot periods without forcing year-round air cooling. Liquid cooling can efficiently remove heat with less evaporation in many designs, especially in high-density AI racks.
Alternative water sources: Treated wastewater and reclaimed water can reduce competition with drinking water supplies when local water quality and treatment allow it.
Better cooling tower operation: DOE guidance explains that increasing the number of concentration cycles can reduce both make-up water and blowdown volumes. DOE’s cooling tower management guidance says raising the number of cycles from three to six can cut make-up water by about 20 percent and blowdown by about 50 percent.
Blowdown treatment and reuse: Research and industry reports describe the recovery and reuse of a large share of blowdown, thereby reducing intake and discharge volumes.
Clear commitments and local investment: Some developers pair projects with water infrastructure spending. Reuters reports Amazon is committing hundreds of millions of dollars toward local water infrastructure alongside new data center buildouts in Louisiana.
Questions Communities And Customers Can Ask
Better questions lead to better projects.
- What is the site’s expected annual water consumption, and what cooling system drives it?
- What share of that water is potable, and what share is reclaimed or non-potable?
- What is the facility’s WUE, and will you report it annually, with context on climate and operating load?
- Where will blowdown and other wastewater streams go, and what pretreatment controls will you use?
- What happens under drought restrictions? Are there hard caps or staged reductions?
- What will you invest in locally? Water infrastructure, watershed restoration, or both?
Where HOBI Fits
HOBI’s data center ITAD services address the needs of liquid-cooled data centers and servers. We support organizations that build, operate, and refresh large technology estates. Water is one ESG risk factor in digital infrastructure. Another is the water, glycol, energy, and materials embedded in the hardware itself. Extending device life through redeployment and resale, and recycling responsibly at the end of life, reduces the need for new manufacturing and reduces upstream resource use. HOBI provides IT asset disposition and data center asset management services with certifications focused on environmental management and secure handling.
Takeaway
Concerns about data centers increasing local water demand and creating wastewater streams are grounded in real engineering. The impact size varies widely by site. Communities, utilities, and developers get better outcomes when water use, discharge plans, and drought contingencies are visible early, and when projects commit to specific controls rather than broad statements.
Frequently Asked Questions
Do data centers really use a lot of water?
It depends on the cooling system and the climate. Sites that use evaporative cooling can consume meaningful volumes, especially during hot periods. Air-cooled or hybrid designs can reduce direct water use, often at the expense of higher electricity use for cooling.
What water quality risks come from data center cooling?
The most common routine stream is cooling tower blowdown, which can carry concentrated minerals and treatment chemicals. Good facilities manage this through pretreatment, sewer acceptance limits, and permits, plus monitoring tied to local wastewater capacity.
What is glycol, and should communities worry about it?
Glycol and water mixes support freeze protection in closed-loop cooling. Under normal operation, glycol stays contained. The main risk is an accidental release to stormwater or surface water, where it can reduce dissolved oxygen. Communities can ask what glycol type is used, how much is stored, and what containment and leak detection measures are in place.
What can a community ask for before approving a project?
Ask for annual water consumption estimates, the share of potable versus reclaimed water, a WUE target with annual reporting, a blowdown routing plan, and a drought plan that states clear operating limits. Also, ask the utility if water and wastewater capacity can support the full buildout, not only phase one.
Where does ITAD fit into water and coolant concerns?
During refresh cycles, retrofits, or decommissioning, systems may be drained and removed. An ITAD partner can help coordinate documented, compliant handling of spent glycol and removal of cooling-related equipment through qualified recycling and waste partners, thereby reducing spill risk and improving audit readiness.