Arapahoe County, CO Noise Ordinances: Decibel Limits (2026)

This is the county's Maximum Permissible Limit for industrial-source noise, but it is scoped narrowly: it governs Oil and Gas Facilities operating under an Administrative Use by Special Review or Use by Special Review inside unincorporated Arapahoe County, not incorporated cities like Aurora or Centennial and not general commercial or manufacturing uses. The standard requires a County-approved third-party consultant to run continuous noise monitoring in 15-minute increments near the well site from construction through the first six months of production, with records kept for two years and made available to the County on request.

Before applying, the Operator must complete an ambient noise survey no more than 90 days before submitting the application and run noise modeling for drilling and completion activity; the results feed a required Noise Mitigation Plan that documents sound walls, Tier 4 diesel engines, mufflers, or Quiet Fleet-style equipment used to hold emissions under the limit. 5. Facility signage must post a 24-hour contact number for noise complaints alongside the ECMC hotline. 6, up to $15,000 for an initial violation and $15,000 per day it continues, appealable to the Board of County Commissioners within 14 days.

Ordinary industrial-zoned uses outside the oil-and-gas program instead follow the more general I-1/I-2 district rule that noise 'shall not extend beyond property lines,' without a decibel figure attached.