Dorchester County, SC Noise Ordinances: Decibel Limits (2026)

2 of the county's Zoning and Land Development Standards regulates noise as an externality that all land uses and development activities must mitigate to avoid adverse impacts on adjacent properties. The section first bars any noise that is objectionable due to intermittence, beat, frequency, or shrillness, then sets numeric maximums measured in decibels (dB) at the property line: 90 dB for industrial, mining, timbering, transportation, and warehousing uses; 80 dB for general commercial uses not specified otherwise; 70 dB for professional and personal service, office, and medium- and high-density residential uses; and 60 dB for low-density residential and agricultural uses.

m. , every one of those permissible continuous noise levels must be reduced by ten decibels (10 dB), effectively dropping the industrial ceiling to 80 dB at night and the low-density residential/agricultural ceiling to 50 dB. The ordinance also allows for brief loud events: sudden, peak noise levels may run up to five decibels (5 dB) above whatever continuous limit applies to that use group and time of day, recognizing that momentary spikes (a truck backing up, a door slamming) are different from a sustained hum or drone.

Because the limits are use-based rather than zoning-district based, a use is measured against the noise ceiling assigned to its category (industrial, commercial, office/mid-density residential, or low-density residential/agricultural) regardless of which zoning district it sits in, with compliance measured at the property line shared with the neighboring parcel.