310 CMR 7.10  Noise

(1) No person owning, leasing, or controlling a source of sound shall willfully, negligently, or through failure to provide necessary equipment, service, or maintenance or to take necessary precautions cause, suffer, allow, or permit unnecessary emissions from said source of sound that may cause noise.

(2) 310 CMR 7.10(1) shall pertain to, but shall not be limited to, prolonged unattended sounding of burglar alarms, construction and demolition equipment which characteristically emit sound but which may be fitted and accommodated with equipment such as enclosures to suppress sound or may be operated in a manner so as to suppress sound, suppressible and preventable industrial and commercial sources of sound, and other man-made sounds that cause noise.

(3) 310 CMR 7.10(1) shall not apply to sounds emitted during and associated with:

1. parades, public gatherings, or sporting events, for which permits have been issued provided that said parades, public gatherings, or sporting events in one city or town do not cause noise in another city or town;
2. emergency police, fire, and ambulance vehicles;
3. police, fire, and civil and national defense activities;
4. domestic equipment such as lawn mowers and power saws between the hours of 7:00 A.M. and 9:00 P.M.

The DEP has established a Noise Level Policy for implementing this regulation. The policy specifies that the ambient sound level, measured at the property line of the facility or at the nearest inhabited buildings, shall not be increased by more than 10 decibels weighted for the "A" scale [dB(A)] due to the sound from the facility during its operating hours.

The ambient sound level is the sound from all sources other than the particular sound of interest; also known as the background sound level. The ambient sound measurement (A-weighted sound level) is taken where the offending sound cannot be heard, or with the sound source shut-off. The ambient sound level is rarely found to be constant over time, and is usually quite variable. The ambient sound level is considered to be the level that is exceeded 90% of the time that the noise measurements are taken. The ambient sound level may also be established by other means with the consent of the DEP.

The dB(A) unit of sound measurement is altered (or weighted) to reflect human sound sensitivity. For instance, for those frequencies of sound which humans hear very well, the actual reading is enhanced, or increased, in the weighting process. The "weighted" reading therefore emphasizes the frequencies best heard by humans, and likewise de-emphasizes those sound frequencies which are less well heard.

The guideline further states that the facility shall not produce a pure-tone condition at the property line (or at the nearest inhabited buildings). A pure-tone exists if the sound pressure level, at any given octave band center frequency, exceeds the levels of the two adjacent octave bands by three (3) or more decibels.

The Massachusetts Department of Environmental Protection (DEP) adopted this Noise Control Regulation, 310 CMR 7.10, under the authority of M.G.L. Chapter 111, Section 142B and 142D. The Noise Control Regulation is used to limit the sound impact of new stationary sources and to respond to complaints of certain excessive sound. The DEP Noise Control Regulation can be enforced by local officials under the authority of 310 CMR7.52

310 CMR 7.52  Enforcement Provisions

"Any police department, fire department, board of health officials, or building inspector or his designee acting within his jurisdictional area is hereby authorized by the DEP to enforce, as provided in M.G.L. c. 111, S 142B, any regulation in which specific reference to 310 CMR 7.52 is cited."
Noise is defined in the Regulations as "...sound of sufficient intensity and/or duration as to cause or contribute to a condition of air pollution."

A source of sound will be considered to be in compliance with the DEP noise regulation 310 CMR 7.10(1) if the source does not:

1. Increase the broadband sound level by more than 10 dB(A) above ambient, or
2. Produce a pure tone condition.