Noise Waivers & Suppression Plans
Occasionally, public works construction projects are done during hours that fall outside the County-designated normal construction hours of Monday through Friday 7 am to 5 pm These projects are usually done in response to directives by state and local agencies to address traffic congestion and pedestrian safety issues.
Temporary Noise Waivers
The Montgomery County Noise Control Law 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.
Online Temporary Noise Waiver Form
White Noise Backup Alarm Requirements
One of the most frequent complaints received concerns the noise from vehicle and equipment tonal backup alarms used at construction sites. New technology exists in the form of white noise back up alarms. The white noise alarms use broadband technology that creates a “ssh-ssh” sound which is gentle on the ear and dissipates quickly, unlike tonal alarms that produce a high-pitched tone that carries far from the work site. White noise alarms can only be heard in the immediate danger zone reducing the environmental impact of work sites.
OSHA requires the use of backup or reverse signal alarms under the following circumstances:
- Title 29 CFR 1926.601(b)(4) states: No employer shall use any motor vehicle equipment having an obstructed view to the rear unless:
- (i) The vehicle has a reverse signal alarm audible above the surrounding noise level or:
- (ii) The vehicle is backed up only when an observer signals that it is safe to do so.
- Section 1926.602(a)(9)(ii) states: No employer shall permit earthmoving or compacting equipment which has an obstructed view to the rear to be used in reverse gear unless the equipment has in operation a reverse signal alarm distinguishable from the surrounding noise level or an employee signals that it is safe to do so.
OSHA does not specify that a reverse signal alarm be of single-tone type. White noise alarms that are audible above the surrounding noise level provide adequate warning to workers in the path of the vehicle, and to workers walking towards the path of the vehicle in time to avoid contact and comply with OSHA standards.
White noise backup alarms are required as a condition to perform work on the Purple Line project, and this new technology is becoming more common place. Effective May 1, 2022, contractors obtaining Temporary Noise Waivers for after-hours construction will be required to use white noise backup alarms on all vehicles and construction equipment operating on the work site.
Please ensure all sub-contractors and materials delivery drivers are informed of this requirement, and all contractor owned, and rental construction equipment is equipped with white noise backup alarms.
| Activity | Single Source (A) | Multiple Source (B) | Hearing (C) |
|---|---|---|---|
| Residential, single-family | $50 | $100 | |
| Residential, all others | $230 | $230 + ($25 per source/site) | $500 |
| Construction (all types private) | $350 | $350 + ($25 per source/site) | $500 |
| Commercial | $350 | $350 + ($25 per source/site) | $500 |
| Industrial | $350 | $350 + ($25 per source/site) | $500 |
| Transportation | $350 | $350 + ($25 per source/site) | $500 |
| Government | $350 | $350 + ($25 per source/site) | $500 |
Noise Suppression Plans
- 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 Law 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.
A Noise Suppression Plan (NSP) is a plan written and developed under the guidance of an engineer familiar with the principles of acoustics. A NSP will detail the use of the most effective noise-suppression equipment, materials, and methods appropriate and reasonably available for a particular type of construction. As a minimum a NSP must contain the following:
- A detailed scope of the work to be performed, why the project can not comply with the current construction noise standard, the duration of the project, and the expected noise levels to be produced during the project.
- A scaled site map which accurately depicts the exact location of the project, the project boundaries, and all affected residential and business properties within a radius of 1000 feet of the construction site.
- Explain how the implementation of the proposed NSP will benefit the public.
- A detailed description of the noise-suppression equipment, materials, and methods to be employed for this project.
- Upon receipt and review of a NSP the Department of Environmental Protection (DEP) will prepare a Public Notice and send it to the applicant.
- The applicant will distribute the public notice to all properties within 1000’ of the work site. Distribution may be done by mail or hand delivery, and only one notice is required to be delivered to the property management office of multi-tenant residential and office buildings.
- Upon confirmation of the public notice distribution, DEP will begin the 10-day public comment period.
- DEP will forward to the applicant any relevant public comments for response.
- DEP may approve the NSP upon completion of the 10-day comment period.
- The applicant must develop and distribute a Community Notice prior to commencement of work. The notice shall contain a description of the project, duration, noise mitigation measures to be used, and on-site contact information for the contractor. A copy of the Community Notice shall be forwarded to DEP with confirmation of the date of distribution.
Pile Driving – Additional Information Required
- Site plan map showing the location of each proposed pile with a list of distances to the closest residential unit.
- Noise modeling map showing the projected decibel levels to the closest nearby residences. This shall be prepared by a trained acoustical professional competent in noise modeling.
- Technical specifications for the pile driving hammer and a description of the hammer operator’s procedures, i.e., will the hammer power level vary according to the substrate composition.
- A description of the substrate composition (geotechnical data) on the site.
- The sequence of pile installation including the projected number of days/dates to complete the piling installations. How is the pile installation planned to progress around the site?
- A list of noise mitigation measures that will be used to ensure the noise level from pile driving does not exceed the 85 dBA maximum allowed.
- Procedures for notifying the nearby residential communities of the work status and who they contact to report noise issues.
- Procedures for responding to noise complaints from nearby residents.
- A detailed plan describing how sound levels will be monitored when pile driving is occurring. This shall include a description of the sound meter, meter operator training, monitoring locations, and number of sound measurements.
NOTE: The 85 decibel limit, if approved, will only apply from 7:00 AM until 5:00 PM, Monday through Friday. At all other times, including weekday Federal holidays, the maximum noise levels must comply with the noise limits as specified in Section 31B-6 of the Montgomery County Code.