Placer County, CA Data Centers & Crypto Mining: Data Center Noise Limits (2026)
Key Facts
- Daytime Limit
- 55 dB Leq (7am-10pm)
- Nighttime Limit
- 45 dB Leq (10pm-7am)
- Alternative Standard
- Ambient + 5 dBA
- Governing Code
- County Code Art. 9.36, Sec. 9.36.060
- Also Reviewed
- CEQA noise analysis
Summary
Placer County's Noise Code (County Code Article 9.36) caps stationary-source sound at a sensitive receptor's property line at 55 dB daytime and 45 dB nighttime hourly Leq, or 5 dBA over ambient, whichever is greater. A data center's cooling systems and backup generators must meet these limits.
Causes the exterior sound level when measured at the property line of any affected sensitive receptor to exceed the ambient sound level by five dBA or ... Exceeds the sound level standards as set forth in Table 1, whichever is the greater.
Full Breakdown
Placer County has no noise rule written specifically for data centers, so a facility's chillers, cooling fans, and diesel backup generators are held to the countywide Noise Code, Article 9.36 of the Placer County Code (Ord. 5280-B, 2004). Section 9.36.060 makes it unlawful to create sound exceeding the ambient level by five dBA, or exceeding the Table 1 standards, whichever is greater, measured at the property line of any affected sensitive receptor. Table 1 sets an hourly Leq of 55 dB daytime (7 a.m. to 10 p.m.) and 45 dB nighttime (10 p.m. to 7 a.m.), with maximum levels of 70 and 65 dB. Generator-testing noise is also analyzed in CEQA, which can require enclosures, barrier walls, or silencers.
Violations & Fines
Cooling or generator noise exceeding 55 dB by day or 45 dB at night at a sensitive receptor's property line violates Article 9.36. Placer County can require mitigation, and unmitigated impacts can condition approval under CEQA.
Frequently Asked Questions
How loud can a Placer County data center be?
Are data center backup generators regulated for noise?
Sources & Official References
Other rules in Placer County
California rules heatmap·Compare Placer County to another location·View the California data centers & crypto mining overview
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