MoCo Code Chapter 31B sets decibel limits by zone in Rockville. Residential: 65/55 dBA day/night. Commercial: 67/62 dBA. Industrial: 75/70 dBA.
Montgomery County Code Chapter 31B establishes quantitative decibel limits measured in A-weighted decibels (dBA) at the property line of the receiving property. For residential receiving properties, the maximum is 65 dBA during daytime (7 AM to 9 PM weekdays, 9 AM to 9 PM weekends and holidays) and 55 dBA during nighttime (9 PM to 7 AM weekdays, 9 PM to 9 AM weekends and holidays). Commercial receiving properties allow 67 dBA daytime and 62 dBA nighttime. Industrial receiving properties allow 75 dBA daytime and 70 dBA nighttime. Measurements are taken at the location on the receiving property where noise from the source is greatest. Background noise, traffic, and other ambient sounds are factored into enforcement decisions. The Maryland Environment Article also establishes state-level environmental noise standards through COMAR 26.02.03, which sets maximum allowable noise levels at residential property boundaries. Montgomery County DEP uses calibrated sound-level meters for enforcement. Noise waivers may be granted for specific activities that temporarily exceed these limits.
Exceeding decibel limits results in fines of $100 to $500 per violation. The DEP may require noise mitigation measures and can seek injunctive relief for persistent violators.
See how other cities in Montgomery County handle decibel limits.
See how Rockville's decibel limits rules stack up against other locations.
Quick Compare
Help us keep this page accurate. If you notice an error or outdated information, let us know.