Somerville, MA Noise from Specific Sources: Generator Noise (2026)

Sec. 9-116(7), titled 'Engine exhausts,' prohibits discharging the exhaust of any steam engine, gasoline engine, stationary internal combustion engine, or other kind of engine into the open air within the city except through a muffler or other device that effectively prevents loud or explosive noise, and it expressly lists stationary internal combustion engines alongside motor vehicles, so a backup power generator, a portable job-site generator, or a compressor is treated identically to a car's tailpipe. Because the ordinance defines 'noise disturbance' broadly in Sec. 9-115 as any sound that annoys, disturbs, injures, or endangers the comfort, repose, health, peace, or safety of others within city limits, a generator does not need to hit a specific decibel number to violate this section; an unmuffled or poorly muffled engine that a neighbor can reasonably say disturbs their peace is enough.

c. 90, § 16 for the fine that applies when the discharge involves a motor vehicle, but for a stationary engine the general municipal penalty in Sec. 1-11, a $300 fine per offense, applies instead, with each day of continued unmuffled operation counted separately. Enforcement runs through the chief of police and the superintendent of inspectional services under Sec. c. 40, § 21D rather than criminal prosecution.