Noise Control

Montgomery County’s noise control law does not contain any specific sound limits applicable to internal noise. The sound limits established in the law are for external noise measured outside at the property line.

Issues involving routine sounds associated with living in a multifamily setting, such as loud voices, heavy footsteps, doors slamming, dropping objects on the floor, children playing, or running pets are the responsibility of the building manager or property management company to resolve.

Please refer to your lease or the covenants for your condominium or cooperative housing association to understand the conditions related to the entitlement of peace and quiet enjoyment of your living space. Failure of the building manager or property management company to provide a living space without recurring sound-related disruptions may constitute a breach of the lease or association covenants.

The Montgomery County Office of Landlord-Tenant Affairs, 240-777-0311, can help with questions regarding your reasonable expectation of peace and quiet enjoyment of your living space.

Outdoor amplified sound can be a pleasurable experience at a restaurant, music event, or party, but it can create noise problems for surrounding neighbors if not adequately controlled. Other forms of amplified sound, such as an outdoor PA system used at a place of business or sporting event, can be another source of unwanted noise, which can sometimes carry a considerable distance from the source.

All outdoor amplified sound must comply with the decibel limits established in the Noise Control Law, which are measured at the nearest residential receiving property line. The established limits are:

The Montgomery County Noise Control Law limits the hours of the day during which power tools and lawn and garden equipment may be operated.

All residential yard care and landscaping activities and commercial equipment operation may not begin until 7 a.m. weekdays and 9 a.m. on weekends and holidays.

Leaf Blower Noise

The primary noise concern related to landscaping and yard care is the use of leaf blowers.

A leaf blower is defined as any portable device designed or intended to blow, vacuum, or move leaves or any other type of debris or material by generating a concentrated stream of air. Leaf blowers include devices or machines that accept vacuum attachments.

In July 1989, after extensive discussion, testimony, and public hearings, the Montgomery County Council amended the County Noise Law (Chapter 31B, Section 31B-11, Montgomery County Code) to specifically regulate noise from leaf blowers. The amendment became effective July 1, 1990. It was reconfirmed and included in the comprehensive revision of the Noise Control Law that became effective March 13, 1996. On September 27, 2023, the County Noise Law was amended to ban the sale and use of combustion engine-powered leaf blowers and vacuums.

Leaf Blower Standard

A person must not sell, buy, offer for sale, or use a leaf blower at any time that has an  average sound level exceeding 70 dBA (A-weighted decibels) at a distance of 50 feet. This requirement is in addition to any other noise level or noise disturbance standard that applies under the Noise Law. The Department of Environmental Protection (DEP) must apply the current leaf blower testing standard of the American National Standards Institute (ANSI) to determine the noise level at 50 feet.

After  July 1, 2024 handheld, backpack, or walk behind gas-powered leaf blowers and vacuums may not be sold in Montgomery County and after  July 1, 2025 handheld, backpack, or walk behind gas-powered leaf blowers and vacuums may not be used in Montgomery County. Retailers will be required to provide notice to customers on the forthcoming ban on the sale and use of gas-powered leaf blowers. The County’s Department of Environmental Protection will provide the notice signs for retail businesses to use in their stores. Learn more about the new regulations on the Leaf Blowers page.

DEP may inspect—and on its request a person must produce—any leaf blower that is sold, offered for sale, or used in the County, to determine whether the leaf blower complies with the law. Until July 1, 2025, a person who relies in good faith on a manufacturer's written representation of the sound level for a combustion engine-powered handheld, backpack, or walk-behind leaf blower that has not been modified is not subject to a penalty for violation.

It is the intention of DEP to facilitate voluntary and amicable compliance with this Law among all concerned. However, upon conviction,  violators are subject to a civil fine of $500 for the first offense, $750 for subsequent offenses, and other relief as allowed by law.

Commercial buildings are required to have emergency standby generators to operate emergency lights, elevators, fire alarms and fire pumps during power outages. Also, in recent years it has become increasingly popular for homeowners to install emergency standby generators. Consequently, the number of noise complaints related to emergency standby generators has been steadily increasing.

Problems may be avoided through careful planning, design, equipment selection and installation. Almost all manufactured products, including generators, have noise performance specifications. Potential noise sources that can operate on a 24-hour basis, such as  standby generators, are required to meet Montgomery County's more restrictive nighttime standard of 55 dBA (A-weighted decibels) at the nearest receiving residential property line.

Things to Consider when Planning for the Installation of an Emergency Standby Electric Generator:

1. Purchase the quietest generator available. It is much easier to start with equipment that can meet the standard than try to retrofit equipment with noise suppression features later.
2. The physical location of the generator should be chosen to minimize noise impacts to both on-site occupants and all nearby neighbors.
3. The general rule of thumb is every time you double the distance from a point noise source you get a corresponding 6 dBA drop in sound pressure. Therefore, if the level is 62 dBA at 7 meters it would be 56 dBA at 14 meters, and 50 dBA at 28 meters, and so on. Noise measurements are typically taken from a complainant’s closest property line.
4. Schedule the recommended periodic testing of generators to occur at times when building occupants and nearby neighbors are least likely to be disturbed.
5. The regulations grant a 2.5 dBA allowance for any possible inaccuracies in the sound meter or the operator. The actual nighttime standard is therefore 57.5 dBA or lower.
6. If distance is a restricting factor, consider constructing a noise barrier to reduce the sound. Several commercial "noise attenuation" or "acoustic enclosure" solutions are available.

DEP works with the Department of Permitting Services to distribute noise information with applications  for permits to install electric generators.  Ultimately it is the property owner’s responsibility to ensure the noise from their generator is in compliance with the nighttime decibel standard.
DEP does not make recommendations for makes and models of equipment that comply with the current nighttime decibel standard.
Questions about Electric Generators and Air Quality? Visit our outdoor air quality page.

Trash companies and their employees are not allowed to collect solid wastes and recyclables in Montgomery County before 7 am (9 am on federal holidays and Sundays) or to collect after 9 p.m. on any day (Monday through Sunday, including federal holidays). However, collections may be made at any time from business establishments such as commercial, industrial, institutional, or other nonresidential use structures provided that there is no residential structure within 500 feet of the collection point.

The Solid Waste Ordinance allows trash collection to begin at 7 am on Saturday, however please be aware the Quiet Hours mandated by the Montgomery County Noise Control Ordinance are in effect until 9 am on Saturday. Therefore, trash collection between 7 am and 9 am on Saturday can result in creation of a noise disturbance, which can be a noise violation. Therefore, it is highly recommended that commercial trash collection be delayed until 9 a.m. when there are residences located within 500 feet of the collection point.

If you experience a trash collection noise problem during quiet hours, contact 311.

Commercial parking lot cleaning activities employ vacuum trucks and leaf blowers to collect and remove debris. Owners and property managers of commercial buildings and retail establishments generally prefer lot cleaning activities be performed after their business hours. This often times means that lot cleaning activities are occurring after 9 p.m. during quiet hours, and sometimes within close proximity to residences.

The maximum allowable sound levels, measured at the nearest receiving property line, are as follows:

While it is understandable that lot cleaning contractors may have to service a particular location during nighttime hours, there are things that can be done to minimize the impact of noise on nearby residences, which includes:

• Clean areas closest to residences as early as possible.
• Use non-motorized hand cleaning methods on areas closest to residences.
• Incorporate noise control considerations when bidding and/or soliciting new contracts.
• Communicate with the surrounding community.
• Select equipment for its low-noise-emission design.

For more information, email DEP at [email protected] or contact 311.

Construction and development projects are by their nature not quiet. However, with careful planning and operation, it's possible to minimize potential noise disturbances from construction activities. Construction workers, contractors and engineers, should be aware of how activities are regulated under the Montgomery County Noise Control Law.

• Learn about Construction Noise
• View pending and approved noise waivers and suppression plans