Common Types of Noise Disturbance
Click the tabs to the right to read about the most common types of noise disturbances in Montgomery County. Visit the Noise Disturbance page or the Noise Ordinance page for more information on how noise disturbance is classified and the details of the noise control ordinance.
Music and PA Systems
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 Ordinance, which are measured at the nearest residential receiving property line. The established limits are:
Yard Maintenance and Leaf Blowers
The Montgomery County Noise Control Ordinance limits the hours of the day during which power tools and lawn and garden equipment may be operated.
Leaf Blower Noise
The primary noise concern related to landscaping and yard care is the use of leaf blowers that might cause unnecessary and unusual noise disturbances.
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 Ordinance (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 Ordinance that became effective March 13, 1996.
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 Ordinance. The Department of Environmental Protection (DEP) must apply the standard in accordance with the most current leaf blower testing standard of the American National Standards Institute (ANSI).
Manufacturers, distributors and retailers are encouraged to submit design and performance data to DEP on all units offered for sale in Montgomery County to demonstrate compliance with ANSI standard. They are further encouraged to conform to the labeling recommendations of the ANSI standard. Without such information and labeling, DEP may order suspension of sale of a specific unit until such test and performance data is obtained.
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. A person who relies in good faith on a manufacturer's written representation of the sound level of a 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 ordinance section 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.
File a Complaint
Emergency Standby Electric Generators
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:
The Montgomery County Noise Control Ordinance was first passed by the County Council in 1975, and the ordinance was revised in 1996. 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 a.m. (9 a.m. 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.
If you experience a trash collection noise problem during quiet hours, contact 311.
Parking Lot Cleaning
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:
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 Ordinance.
If after reading this information you believe a construction site is in violation of the Montgomery County Noise Control Ordinance, click here to File a Two-Party Noise Complaint.
Construction Noise Basics
Virtually all potential noise sources that operate permanently or semipermanently can be designed or controlled to meet the receiving property line standard. Likewise, potential sources under human control, such as electronically amplified sound, can be designed to meet the ordinance requirements.
Noise from some construction activities, however, is difficult, if not impossible, to control to the receiving property line. This is because the engineering design and technical controls that are effective on stationary sources aren't practical or reasonable for a temporary, often mobile, noise source.
The Noise Control Ordinance, therefore, contains certain standards specific to construction noise. DEP has several tools available to help mitigate and regulate this potential source of disturbance.
Construction Noise Exemptions and Standards
The Montgomery County Noise Control Ordinance defines construction as temporary activities directly associated with site preparation, assembly, erection, repair, alteration, or demolition of structures or roadways. Construction noise levels must be measured on a receiving property, but no closer than 50 feet from the noise source.
Notice to Contractors
From 7 a.m. to 5 p.m. weekdays, construction noise levels must not exceed:
At all times other than 7 a.m. to 5 p.m. weekdays, the general ordinance guidelines in the Noise Control Ordinance must be met. The following table provides a summary of the noise standards for construction activities:
*In most circumstances in the County, the receiving property will be considered residential.
** The U.S. Office of Personnel Management has a list of federally recognized holidays.
Be Aware! Construction activities are also subject to the "Noise Disturbance" provisions of the ordinance. Although a noise disturbance could conceivably occur at any time, it is most likely to happen during nighttime hours. The following are examples of noise disturbances:
The County mails copies of the revised ordinance upon request. If you have questions or comments, contact 311.
Tools for Regulating Construction Noise
In addition to the Noise Control Ordinance, DEP has several mechanisms for controlling and regulating construction noise.
Noise Suppression Plan
A Noise Suppression Plan is a written plan to use the most effective noise-suppressing equipment, materials, and methods appropriate and reasonably available for a particular type of construction.
Several construction activities, such as pile driving and hoe ramming, might inherently exceed 75 dBA, depending on the circumstances. In those cases, the Montgomery County Noise Control Ordinance allows up to 85 dBA, provided a Noise Suppression Plan, approved by DEP, is implemented. Essentially, these plans require the best reasonably available control technology or strategy. They might involve equipment selection, scheduling, and temporary noise control devices to block or absorb the sound.
Read the full text of the Montgomery County Noise Suppression Plan Guidelines (PDF, 488KB) to learn more.
Temporary Noise Waiver
Occasionally, public works construction projects are done during hours that fall outside the County-designated normal construction hours of Monday through Friday 7 a.m. to 5 p.m. These projects are usually done in response to directives by state and local agencies to address traffic congestion and pedestrian safety issues. The Montgomery County Noise Control Ordinance allows for the issuance of a Temporary Noise Waiver to allow after-hours and nighttime construction projects if the benefit to the public offsets the noise the event will create in excess of the established limits. Refer to the application form and fee schedule below, and allow 30 days for the processing of your Temporary Noise Waiver application.
The following fees apply for exemption applications:
Active Nighttime Construction Projects with Approved Noise Waivers:
Tips for Construction Site Managers
Useful tips learned from previous construction projects include the following:
Proactive and reasonable control of construction noise results in more content communities and successful, on-schedule projects with a minimum of hassle due to noise. It also removes the inconvenience of civil penalties, abatement orders, or stop work orders.
Calculating Sound Intensity
Noise emissions from all mechanical equipment must be expressed, in A-weighted decibels (dBA), measured at a stated reference distance. It's your responsibility to calculate the estimated sound intensity (in dBA) to ensure that it complies with the Montgomery County Noise Control Ordinance. The following guidance can help you:
These estimations are especially useful in determining equipment or facility placement (e.g. loading docks), or in the design of engineering controls. All calculations and assumptions should be submitted to the reviewing authority.
Note: Most equipment manufacturers, and especially those who produce or market in Europe or Asia, have detailed noise performance specifications for their products.