Marin County, CA Data Centers & Crypto Mining: Data Center Noise Limits (2026)
Key Facts
- Daytime Limit
- 50 dBA Leq (7am-10pm)
- Nighttime Limit
- 45 dBA Leq (10pm-7am)
- Measured At
- Receiving-use property line
- Impulsive Max Level
- 65 / 60 dBA
- Governing Standard
- Countywide Plan Figure 3-43
Summary
Marin County caps new stationary-source noise at 50 dBA Leq daytime and 45 dBA Leq at night, measured at the property line of the affected home. A data center's cooling and generators would be held to these Countywide Plan Noise Element benchmarks through permit and CEQA review.
The Benchmarks for Allowable Noise Exposure from Stationary Noise Sources in Figure 3-43 shall be used as a guide for establishing allowable noise levels produced by stationary noise sources. These standards shall apply to new residential projects and other noise-sensitive land uses proposed near stationary noise sources.
Full Breakdown
The Marin Countywide Plan Built Environment Element sets the noise benchmarks applied during permit and CEQA review. Program NO-1.a and Figure 3-43, Benchmarks for Allowable Noise Exposure from Stationary Noise Sources, set an exterior hourly Leq of 50 dBA from 7 a.m. to 10 p.m. and 45 dBA from 10 p.m. to 7 a.m. at the property line of the receiving land use, with maximum-level tiers of 70/65 and 65/60 dBA for impulsive noise. The standard rises to match a neighborhood that is already louder. A data center's chillers, cooling fans, and generator testing would be conditioned to meet these limits. The county's Municipal Code noise chapter (6.70) mainly addresses construction and nuisance noise, not a numeric stationary cap.
Violations & Fines
Cooling or generator noise exceeding the Figure 3-43 benchmarks at a neighboring property line violates a project's conditions of approval. The Community Development Agency can require added mitigation, issue notices of violation, and withhold or condition permits under CEQA.
Frequently Asked Questions
How loud can a data center be in unincorporated Marin County?
Where is data-center noise measured in Marin County?
Sources & Official References
Other rules in Marin County
California rules heatmap·Compare Marin County to another location·View the California data centers & crypto mining overview
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