Napa County, CA Data Centers & Crypto Mining: Data Center Noise Limits (2026)
Key Facts
- Nighttime Limit
- 45 dBA (10pm-7am)
- Daytime Limit
- 50 dBA (7am-10pm)
- Measured At
- Neighboring residential property line
- Tonal-Noise Penalty
- Minus 5 dBA
- Governing Code
- Section 8.16.070
Summary
Napa County caps exterior noise at 45 dBA at night and 50 dBA by day at a neighboring rural home's property line, under Code Section 8.16.070. A data center's cooling equipment and generators would be held to these limits through permit and CEQA review.
The standard limits set forth in this table shall be reduced by 5 dB, but not to lower than 45 dB, for any offensive noise that contains a steady, audible tone such as a whine, screech or hum, or that is a repetitive noise such as hammering or riveting, or that contains music or speech.
Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: Code of Ordinances: Supplement 48 | General Policies and Bylaws: ? | Fees and Archived Fees: ?).
Full Breakdown
Napa County Code Section 8.16.070 sets maximum exterior noise limits enforced against stationary sources such as mechanical equipment. At a rural residential property line the limit is 45 dBA from 10 p.m. to 7 a.m. and 50 dBA from 7 a.m. to 10 p.m.; suburban residential limits run 45 to 55 dBA, and industrial areas 75 dBA anytime. Any steady tonal or humming noise, precisely the sound of data-center chillers and cooling fans, triggers a 5 dBA reduction, tightening the nighttime limit toward 45 dBA. A data center's equipment and backup-generator testing would be conditioned to meet these standards during use-permit and CEQA review.
Violations & Fines
Operating equipment that exceeds the Section 8.16.070 limits at a neighboring property line violates the county noise ordinance and any project conditions of approval. The county can require added mitigation, issue notices of violation, and pursue enforcement.
Frequently Asked Questions
What is the noise limit for data-center equipment in Napa County?
Where is data-center noise measured in Napa County?
Sources & Official References
Other rules in Napa County
California rules heatmap·Compare Napa County to another location·View the California data centers & crypto mining overview
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