66B L
Estimated direct U.S. data-center water consumption in 2023, according to Lawrence Berkeley National Laboratory.
Why now?
Because the buildout is happening now, and water rules written after the infrastructure is locked in will be too late.
Evaporation
DOE describes evaporation as the basic heat-rejection mechanism of conventional cooling towers — water is intentionally transferred to the atmosphere.
Already possible
Closed-loop, direct-to-chip and air-cooled designs can reject heat without routine cooling-water evaporation. This is an engineering choice, not a law of nature.
The Water Custody Standard
One principle: a data center does not gain a consumptive right to community water merely because it can pay for the withdrawal.
CLEAN RETURN ≥ FRESHWATER WITHDRAWAL
1
Take it under custody.
Every source-water withdrawal crosses a certified inlet meter. Cooling makeup, sanitation, cleaning, landscaping and commissioning all count.
2
Clean what you used.
Wastewater is captured and treated on site or through a dedicated treatment system. Closed-loop coolant remains equipment inventory rather than disposable community water.
3
Return it now.
Certified clean liquid water crosses a return meter during the same operating period. Storage may buffer treatment time; long-term promises and distant offsets do not count.
What counts — and what does not.
The standard is deliberately physical. If the water is not clean, liquid, local and measured, the community has not been made whole.
✓ Volume parity
Returned liquid volume must equal or exceed metered freshwater withdrawal.
✓ Quality parity
Returned water must meet a defined quality standard appropriate to the receiving system, with continuous monitoring plus laboratory verification.
✓ Thermal parity
Water cannot simply be returned dangerously hot. Heat must be rejected before discharge or reuse.
✓ Real-time accountability
A hydraulic balance tracks intake, on-site inventory and certified return. Persistent deficits restrict additional withdrawal.
✕ No evaporation credits
Water intentionally evaporated into the atmosphere is consumed water, not returned water.
✕ No distant offsets
A project somewhere else, sometime later, does not replace the water taken from the local system today.
Primary sources
The campaign's factual claims should be easy to audit.
Lawrence Berkeley National Laboratory — 2024 United States Data Center Energy Usage Report
Reports 66 billion liters of direct U.S. data-center water consumption in 2023 and discusses projected growth.
U.S. Department of Energy — Cooling Water Efficiency Opportunities for Federal Data Centers
Explains conventional cooling-tower evaporation, blowdown and water-use mechanisms.
Microsoft — closed-loop cooling without operational water evaporation
Useful evidence that zero-water-evaporation cooling is already technically deployable for modern data-center designs.