Contra Costa County, CA Data Centers & Crypto Mining: Data Center Noise Limits (2026)
Key Facts
- Stationary-Source Ordinance
- None yet adopted
- Residential Standard
- 60 dBA Ldn normally acceptable
- Industrial Standard
- Up to 75 dBA Ldn
- Governing Document
- 2045 GP Table HS-X
- Also Reviewed
- CEQA noise analysis
Summary
Contra Costa County has no codified decibel ordinance for stationary sources. A data center's cooling and generators are held to the 2045 General Plan land-use compatibility standard, a 60 dBA Ldn residential target, industrial normally acceptable to 75 dBA, enforced through CEQA and land-use-permit conditions.
the County's regulations are not comprehensive and there are gaps in coverage.
Full Breakdown
The unincorporated county has no stationary-source noise ordinance with fixed property-line decibel limits, so a data center's chillers, cooling towers, and backup generators are governed by the 2045 General Plan Health and Safety Element and CEQA. Table HS-X sets land-use compatibility: outdoor noise is 'normally acceptable' up to 60 dBA Ldn for residential uses and up to 75 dBA Ldn for industrial and manufacturing uses. Policy HS-P14.1 requires an acoustical analysis where a noise-sensitive use would sit above the normally acceptable level, and HS-P14.5 requires mitigation for projects raising long-term noise above set thresholds at a sensitive use's property line. The county is studying a dedicated stationary-source noise ordinance under Action HS-A14.1.
Violations & Fines
Cooling or generator noise that breaches a project's CEQA-based conditions or the General Plan compatibility standards can trigger mitigation orders, added permit conditions, or permit denial. Construction outside the HS-P14.7 hours near homes is enforced through the permit.
Frequently Asked Questions
How loud can a data center be in unincorporated Contra Costa County?
Does the county have a noise ordinance for cooling and generator noise?
Sources & Official References
Other rules in Contra Costa County
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