Cass County, MO Data Centers & Crypto Mining: Data Center Noise Limits (2026)

662(E)(5)(a) ties the facility's setback directly to noise: a greater setback than the base 1,000 feet may be required so that sound pressure level (SPL) attributable to data center infrastructure does not exceed 50 dBC at the subject property lines. Subsection E(10)(d), covering generators, restates the same 50 dBC ceiling measured at all data center property lines, and adds a stricter trigger for sensitive neighbors: where the facility sits within 500 feet of any allowed residential use or district, a place of worship, daycare, park, lodging establishment (including bed and breakfast, campground, RV park, hotel, motel, nightly rental or timeshare unit), or an educational facility, the SPL attributable to the facility still cannot exceed 50 dBC at the property line.

Substations carry the identical 50 dBC limit under Subsection E(8)(c). , and no more than once per week, and outdoor generators need a concrete sound barrier extending at least two feet above the unit or ten feet high, whichever is greater. Subsection E(16) requires the permit holder to submit an on-site sound monitoring affidavit to the county before a certificate of occupancy issues, wet-stamped by a Missouri-licensed professional engineer, listing equipment, NIST-traceable calibration certificates, measurement locations at each property line, SPL readings, and a guarantee the facility will never run louder than what was measured; the county can independently verify readings.