Bristol, CT Noise Ordinances: Decibel Limits (2026)

Section 15-21(b) sets a full nine-cell table crossing three emitter zones (industrial, business, residential) against three receptor conditions (industrial, business, residential daytime, residential nighttime). Industrial-to-industrial tops out at 70 dBA, industrial-to-business at 66 dBA, and industrial-to-residential at 61 dBA by day and 51 dBA at night. Business and residential emitters share the same receptor limits: 62 dBA to an industrial receptor, 55 dBA to a business or daytime-residential receptor, and 45 dBA to a residential receptor at night. Night-time hours run 10:00 p.m. to 7:00 a.m.

Sunday through Friday nights and 10:00 p.m. to 9:00 a.m. on Saturday night, per section 15-17. Section 15-21(c) adds a background-noise rule: a source that exceeds the surrounding background level by 5 dBA is a violation, and no source may ever exceed 80 dBA, with impulse noise capped at 80 dB peak at night and 100 dB peak at any hour. Trained personnel using an ANSI S1.4 sound level meter take readings about one foot beyond the emitter's boundary inside the receptor's property under section 15-20.

Exemptions under section 15-19 cover daytime property-maintenance and construction equipment, city-sanctioned events, permitted daytime blasting, refuse collection between 6:00 a.m. and 10:00 p.m., and short-duration fire or intrusion alarms. A property owner may seek a variance from the mayor under section 15-22 by filing at least 20 days ahead; failure to rule within the review period is deemed approval.