Methuen, MA Noise Ordinances: Decibel Limits (2026)

The numeric decibel figures in the Methuen Comprehensive Zoning Ordinance attach to facility types and measurement points rather than to zones or hours of the day. The wireless rule sits in § 11.20, Personal wireless service facilities, added in 1999 by Ord. No. 665, under Subsection E, Environmental standards. Ground-mounted equipment shall not generate noise in excess of 50 decibels at the property line. Roof-mounted or side-mounted equipment shall not generate noise in excess of 50 decibels at ground level at the base of the building closest to the antenna. The Community Development Board retains the right to commission an acoustical engineer to study noise at a proposed site, and the applicant bears the cost.

The application must carry a noise statement listing existing and maximum future projected noise measurements in decibels Ldn, a logarithmic scale accounting for greater sensitivity at night. The statement covers the existing or ambient noise and the existing noise plus the proposed facility, and it must be certified and signed by an acoustical engineer. After the facility is operational, the applicant submits engineer-signed noise measurements within 90 days of the issuance of the special permit and at annual intervals from the date of issuance.

Wind energy conversion facilities have a separate standard in § 11.9(G)(3). They must conform with the Department of Environmental Protection noise regulations at 310 CMR 7.10 unless the Department and the special permit granting authority agree otherwise. A source violates the standard if it increases the broadband sound level by more than 10 dB(A) above ambient, or produces a pure tone condition when an octave band center frequency sound pressure level exceeds the two adjacent levels by three decibels or more. Ambient is the background A-weighted sound level exceeded 90% of the time during equipment hours, and compliance is measured at the property line and at the nearest inhabited residence.