April 15, 2026

Over the past several weeks, as we have begun to bring equipment online at the Mount Pleasant “Fairwater 1” datacenter, community members north of the datacenter have noticed a tonal humming sound and shared their concerns directly with us. Although the facility noise levels meet the requirements set by local ordinance, we take this feedback seriously and understand the impact this has had on our neighbors.

Our engineering team and consultants on site have investigated the source of the sound. They have discovered that it comes from cooling fans that are currently operating at high speeds. We anticipated that our systems would need adjustments and create some noise as part of the datacenter startup, but we did not expect the tonal quality of the sound to travel as far as it has.

What we are doing about it
We are taking immediate steps to address the sound concerns. We are manually adjusting the cooling fans while we complete the remaining startup activities to reflect typical operating conditions. Initial testing has shown positive results, and we expect this change to address community concerns about the tonal humming by Monday, April 20. We will set mechanical operating limits to ensure fan speeds remain in the appropriate range moving forward.

Over the next several months, we will also install additional sound reduction components on the cooling equipment. This work will provide even further reductions in measured sound levels.

Our commitment
Microsoft is committed to being a good neighbor and a responsible member of our local communities. We appreciate the opportunity to operate in Wisconsin, and we take the concerns raised by our neighbors seriously. We appreciate our neighbors’ patience and feedback as our team conducted investigations.

Addressing this sound issue is a priority for us, and we are dedicating the necessary resources and technical focus to resolve it. While bringing a new facility of this scale into its long-term operating condition requires careful adjustment and monitoring, we are actively working through these steps and will continue to do so until the issue is properly addressed.

April 10, 2026

Microsoft prides itself on being a good neighbor in the communities where we operate. We’re aware of the noise concerns raised about our Mount Pleasant facility, we’re investigating the root cause, we’re in contact with our neighbors, and are fully committed to addressing these concerns.