Microsoft Fairwater 1 — Mount Pleasant
Mount Pleasant, Wisconsin Commissioning
Microsoft says most capacity uses a closed loop (pipes that reuse the same water), and the rest uses water “only during the hottest days”. It also acknowledges concerns about startup noise.
- Developer
- Microsoft
- Operator
- Microsoft
- Stage
- Commissioning, as of July 20, 2026
- Records as of
- November 11, 2026
- Scope
- A campus
Microsoft’s update of July 20, 2026 discusses steps to reduce sound (“mitigation”) after it brought equipment online. The listed records do not show whether the site is in full commercial service.
Source: Microsoft, Mount Pleasant sound investigation update, July 20, 2026.
Water
Does the disclosed design cool the whole campus this record covers without evaporating water?
Not knownCompany statement
Microsoft’s design post of September 18, 2025 says over 90% of capacity uses a closed loop. It says the loop needs water only once, during construction, and reuses it “with no evaporation losses”. It says the remaining 10% are traditional servers cooled by outdoor air. They switch to water “only during the hottest days”. The post does not say whether that water evaporates.
Source: Microsoft, Fairwater cooling design, September 18, 2025.
Is a number public for how much water the site or campus needs or consumes?
Not knownCompany statement
The announcement uses comparisons to a restaurant and a golf course. It gives no yearly or highest (“peak”) water demand for the campus as a number.
Source: Microsoft, Wisconsin project and cost commitments, September 18, 2025.
Power
Is clean power accounting for this project public, and does it clearly state the matching period?
Not knownCompany statement
On September 18, 2025, Microsoft said it “will match every kilowatt hour” of power it uses that comes from fossil fuels. It said each match is “one for one with carbon-free energy” that Microsoft puts back onto the grid. It named a new 250 MW solar project in Portage County to support this commitment. The solar project was being built at the time. The statement gives no matching period, such as yearly or hourly. It gives no accounting result.
Source: Microsoft, Wisconsin project and cost commitments, September 18, 2025.
Generators
Is a final air permit for this project public in the listed records?
Not known
The listed records do not answer this.
Noise
Do the listed records show enforceable noise limits, as numbers, for the site when it runs?
Not knownCompany statement
On April 15, 2026, Microsoft said the site’s noise levels “meet the requirements set by local ordinance” (a local law). Its updates do not name that law or give its limits as numbers. On June 18, 2026, Microsoft said its “independent monitoring” showed that its steps to reduce the sound had “fully resolved the issue”. The updates give no measured sound levels. On July 20, 2026, Microsoft said it was still working on short-term steps to reduce the sound.
Source: Microsoft, Mount Pleasant sound investigation update, July 20, 2026.
Costs
Do public records show an adopted tariff or agreement that says who pays the project’s power costs?
Not knownCompany statement
Microsoft says it pays in advance for the energy and electrical infrastructure it will use. The listed records do not include a signed agreement that applies.
Source: Microsoft, Wisconsin project and cost commitments, September 18, 2025.
Promises
Does a public record show a local land-use decision?
Not known
The listed records do not answer this.
What is public
Is there a public disclosure or a government record about this project?
YesCompany statement
Microsoft publishes design details for the project. It also publishes a dated update on its sound investigation.
Sources: Microsoft, Fairwater cooling design, September 18, 2025; Microsoft, Mount Pleasant sound investigation update, July 20, 2026.
Are measured environmental results for the site or campus public, with the dates they cover?
Not knownCompany statement
Microsoft’s sound updates run from 10 April to July 20, 2026. They describe work to reduce the sound. On June 18, 2026, Microsoft said its “independent monitoring” showed that this work had “fully resolved the issue”. The updates give no measured values and no time span for that monitoring. The listed sources show no other measured environmental data for a stated period.
Source: Microsoft, Mount Pleasant sound investigation update, July 20, 2026.
Limits of these records
- A design statement that covers most capacity cannot show how the whole campus gets rid of heat (its “heat-rejection” method).
- The sound update of June 18, 2026 described the matter as resolved. The later update of July 20, 2026 still described evaluation and short-term steps to reduce sound.
- Startup activity does not prove that all planned computing capacity is in commercial operation.