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Tag: Reclaimed Water

  • Amazon’s 7x Water Claim Rests on Hotter Servers, a Test for AI-Era Cooling

    Amazon’s 7x Water Claim Rests on Hotter Servers, a Test for AI-Era Cooling

    TL;DR · 30-second read

    The Short Version

    Amazon says the buildings that run its websites, apps and artificial intelligence services use about one-seventh the water of a typical facility of their kind.

    The main trick is letting the computers run warmer. Outside air cools the buildings about 90% of the time. Water is used only when it is hotter than about 85 degrees Fahrenheit outside.

    This matters because these buildings are multiplying, and their neighbors want to know how much local water they take. The open question is whether the newest artificial intelligence chips, which Amazon says needed a new kind of liquid cooling, will let that approach last.

    Amazon said in a June 11, 2026 post on its About Amazon site that its global data center operations used 0.12 liters of water per kilowatt-hour (L/kWh) in 2025. The company puts that at more than seven times better than an industry average of 0.84 L/kWh and says it is a 52% improvement since 2021. It withdrew about 2.5 billion gallons of water across its global data center footprint in 2025.

    Amazon credits two things for the result. The first is free-air cooling, which it uses about 90% of the time. The second is higher server temperature limits, so that evaporative cooling runs only when outside air is above roughly 85°F. The company also said it is 75% of the way to its 2030 water-positive goal and that it runs 26 facilities on 100% reclaimed water, with 130 more contracted.

    Executive Summary

    Amazon has published a headline water-efficiency figure for its data centers: 0.12 liters of water for every kilowatt-hour of energy in 2025. It set that against an industry average of 0.84. The company explains how it got there. It relies on outside air for most cooling, uses evaporative cooling only in the hottest hours, and has spent several years raising the temperatures its servers are allowed to run at. It says this cut water use without raising hardware failure rates.

    The figure matters because water has become one of the main local questions asked of new data center campuses. Amazon’s explanation also shows that water efficiency is a set of engineering trade-offs, not a fixed property of a building. The company chose to use some water on hot days rather than run chillers, which it says need 25% to 35% more electricity at the moments the grid is most stressed.

    Two things are harder to assess. One is the comparison itself: Amazon did not publish how the 0.84 average was built or on what basis each peer’s figure is measured. The other is the future. Amazon says denser AI chips already required a custom liquid cooling system, so the air-first approach behind the 7x figure now has to hold up as AI capacity grows.

    The Water Number Is Really a Temperature Number

    Amazon’s 0.12 liters per kilowatt-hour did not come from a new water technology. It came from deciding how rarely to use water at all. About 90% of the time, Amazon says, its data centers use free-air cooling. Outside air is drawn past the servers and pushed back out, with no water involved. Water comes into play only through evaporative cooling. In that process, hot air passes through a water-soaked medium and cools by five to 10 degrees as the water evaporates. Amazon now switches that on only when outside air exceeds roughly 85°F.

    That threshold is the lever. Every degree of heat the servers can tolerate removes hours from the evaporative season, so raising operating temperatures cuts water use directly. Amazon’s own evidence is specific:

    • Two identical data centers on the same campus, one running hotter, differed by about 50% in water use.
    • Northern Virginia, its largest region by IT load (the power drawn by the computing equipment itself), cut water use 42% year over year while demand grew.
    • Thousands of hours of campus data showed no increase in failure rates at the higher temperatures.

    Those results fit the 52% efficiency improvement Amazon reports since 2021.

    The same logic is why this is a test for AI-era cooling. The approach depends on air being able to carry heat away from the servers. Amazon itself says denser, more powerful AI chips required a completely custom liquid cooling system. It has not said how much of its fleet now runs that way, whether those systems rely on evaporative water on hot days, or how a growing share of AI capacity will move the 0.12 figure. The air-first playbook behind the 7x gap was proven on the fleet Amazon has run since 2021. Whether it carries over to high-density AI halls is the next data point to watch.

    Water or Watts: The Trade Behind the Ratio

    Amazon is explicit that a low water number is partly a choice about electricity. The alternative it names is chillers, which work like giant air conditioners and, by Amazon’s figures, typically need 25% to 35% more electricity. The timing of that extra load is the problem. It arrives in the hottest hours, when household air conditioning is already straining the grid. Amazon concluded it is better to spend some water on those days than to add power demand at the peak.

    That is a defensible engineering position, and it cuts against a simple reading of water metrics. An operator could report a lower water ratio by running chillers, which shifts the burden onto the grid and, depending on how that electricity is generated, onto water used off site. Conversely, a site that uses more water may be sparing a stressed grid. For utilities and local planners, the useful question is how much water and how much power a campus uses together at the peak hour, not either one in isolation.

    Amazon did not quantify the grid side of its trade. It has not said how much peak demand evaporative cooling avoids across its fleet, or how many hours a year its sites in hot regions exceed 85°F. Without those figures, the argument rests on the chiller penalty range alone.

    Why 0.12 and 0.84 Are Hard to Line Up

    Liters per kilowatt-hour is the industry’s standard water-efficiency ratio, often called water usage effectiveness. It divides the water used for cooling by the energy consumed by the IT equipment. Amazon describes it as water per unit of compute, but the denominator is energy, not work done. A fleet running more efficient chips gets more computing out of each kilowatt-hour, and the metric does not capture that in either direction.

    The 7x claim depends entirely on the 0.84 industry average. Amazon’s chart cites sustainability reports and blogs from Microsoft, Google and Meta alongside its own report. The company did not publish how 0.84 was derived: which operators it covers, how they were weighted, or whether each figure measures water withdrawn (taken from a source) or water consumed (evaporated and not returned). Large operators do not all report water the same way, so a like-for-like reading requires knowing which basis each number uses.

    Scope matters too. Amazon’s absolute figure, about 2.5 billion gallons in 2025, is a withdrawal number for its global data center footprint. The 2% year-over-year decline it cites applies only to sites it owns and operates directly. The company did not say whether the 0.12 ratio is based on withdrawal or consumption, or whether leased facilities are included. None of that makes the claim wrong. It does mean the 7x multiple is Amazon’s own calculation rather than a figure a reader can reproduce from peers’ reports.

    Replenishment and Reclaimed Water Carry the Local Story

    Efficiency is only half of Amazon’s water case. The company has committed to being water positive by 2030, meaning it returns more water to communities than its data center operations use. It says it is 75% of the way there, returning 3 gallons for every 4 used in 2025. It has announced more than 50 projects that are expected to return over 5.8 billion gallons a year once fully implemented, which is more than twice its 2025 withdrawals. Examples include:

    • storing Columbia River winter flows in an aquifer in Hermiston, Oregon;
    • a runoff pipeline in Pina del Ebro, Spain;
    • watershed restoration near Guadalajara, Mexico.

    Replenishment is an accounting balance. Its value to a given town depends on whether the returned water lands in the same basin the data center draws from. Reclaimed water addresses the local question more directly, because it replaces drinking water with treated wastewater at the site itself. Amazon says 26 facilities already run on 100% reclaimed water, more than any other cloud provider, and 130 more are contracted. It has also funded infrastructure and helped with permitting for programs in Mississippi, Hong Kong and Indonesia. If those 130 facilities come online, reclaimed supply may matter as much to neighbors as the headline efficiency ratio.

    Background

    Amazon operates one of the world’s largest data center fleets, mostly to run Amazon Web Services (AWS), its cloud computing business. Data centers convert nearly all the electricity they use into heat, and removing that heat is where most of their water goes. The industry commonly measures water efficiency as liters of water per kilowatt-hour of IT energy, a ratio known as water usage effectiveness, or WUE.

    Amazon has committed to being water positive by 2030 and has expanded its use of reclaimed water from wastewater treatment plants. Amazon says data centers account for less than 0.5% of global industrial water use. Still, where a campus draws its water matters to the surrounding community, and Amazon says its water team is particularly focused on water-scarce areas.

    Sources

    Source: Amazon’s data centers are 7x more water-efficient than the industry average. Here’s how we do it. (About Amazon): Amazon’s account of its 2025 data center water efficiency, cooling methods, and progress toward its water-positive goal.

  • Veolia and Amazon Partner on Reclaimed-Water Cooling for AWS Data Centers

    Veolia and Amazon Partner on Reclaimed-Water Cooling for AWS Data Centers

    Veolia, one of the world’s largest water and environmental services companies, announced on April 27, 2026 that it is working with Amazon to develop a reclaimed-water cooling system for data centers. The collaboration targets Amazon Web Services (AWS) facilities, aiming to substitute treated, recycled water for the potable water that many data centers currently draw for cooling.

    Executive Summary

    The announcement pairs the operator of some of the world’s largest water-treatment networks with the world’s largest cloud provider on one of the industry’s most scrutinized problems: how much drinking-quality water data centers consume to stay cool. Reclaimed water — wastewater that has been treated to a standard fit for industrial reuse, though not for drinking — can displace that potable draw, easing pressure on municipal supplies in the communities where hyperscale campuses cluster.

    For Amazon, the partnership supports its publicly stated goal of becoming “water positive” by 2030 — returning more water to communities than its operations consume — and, just as practically, it addresses a growing source of friction in siting and permitting new capacity. For Veolia, it signals a move to position water expertise as core infrastructure for the AI-era data center buildout. The release, however, is light on specifics: no named sites, volumes, timelines, or financial terms were disclosed.

    Why Water Is the Data Center Industry’s Quiet Constraint

    Power gets most of the headlines, but water is increasingly the constraint that shapes where data centers can be built. Many large facilities use evaporative cooling, which chills servers efficiently by evaporating water — often millions of gallons per year per site, much of it drawn from the same municipal systems that supply homes. In drought-prone regions, that draw has become a genuine permitting and community-relations issue, with local opposition to new campuses increasingly citing water alongside electricity and land.

    The industry measures this through water usage effectiveness (WUE) — water consumed per unit of computing energy delivered — and operators face growing pressure from regulators, investors, and neighbors to disclose and reduce it. A credible, scalable alternative to potable water is therefore worth real money: it can be the difference between a project that clears local approval and one that stalls.

    What Reclaimed Water Solves — and What It Doesn’t

    Reclaimed water is municipal or industrial wastewater treated to a quality suitable for non-potable uses such as irrigation and industrial cooling. Using it for data center cooling substitutes a resource that would otherwise be discharged for one that communities drink. That is a genuine improvement, and it is proven ground: power plants and heavy industry have run on recycled water for decades. The engineering challenge is real but tractable — reclaimed water’s chemistry can promote scaling, corrosion, and biological growth in cooling loops, which is precisely the treatment problem a company like Veolia exists to solve, along with the pipeline infrastructure needed to move recycled water from treatment plants to campuses.

    What reclaimed water does not do is reduce total water consumption. Evaporative cooling still evaporates the water, whatever its source. It changes which water is used, not how much — a meaningful distinction in water-stressed basins, where hydrologists note that treated wastewater returned to rivers also supports downstream flows. The release, as summarized, does not address consumption volumes or how the system compares with closed-loop and other low-water designs.

    The Strategic Logic for Both Sides

    For Veolia, hyperscale data centers represent a growth market adjacent to its core business: the company already operates treatment plants and industrial-water services worldwide, and packaging that capability for cloud providers moves it up the value chain from utility contractor to strategic infrastructure partner in the AI buildout. A named relationship with Amazon is also a powerful reference for selling similar systems to other operators.

    For Amazon, the calculus spans sustainability accounting and siting pragmatism. Progress toward its water-positive pledge requires exactly this kind of substitution at scale, and demonstrating a reclaimed-water pathway gives AWS a stronger story in front of the councils and water authorities that approve new capacity. If the partnership produces a repeatable template rather than a single showcase, it could modestly widen the map of viable data center locations — and put competitive pressure on other hyperscalers, some of which have taken the different route of designs that eliminate evaporative water use entirely.

    Background

    Data center water use moved from an engineering footnote to a public issue over the past several years, as hyperscale construction accelerated to serve cloud and AI demand and communities in water-stressed regions began scrutinizing how much potable water evaporative cooling consumes. The major cloud providers have responded with public commitments — Amazon’s is a pledge to be water positive by 2030 — and with a mix of recycled-water sourcing, more efficient cooling designs, and replenishment projects.

    Veolia, formed from more than a century of French municipal water operations and now one of the world’s largest environmental-services groups, has built its industrial business on exactly this kind of problem: treating and delivering non-potable water for cooling and process use. The April 2026 announcement extends that franchise into hyperscale computing, an infrastructure market whose growth currently outpaces most of the industrial sectors Veolia has traditionally served.

    Source: Veolia Works With Amazon to Develop Reclaimed Water for Cooling System for Data Centers — Veolia press release, April 27, 2026, announcing a collaboration with Amazon on reclaimed-water cooling for AWS data centers.