Portola Valley Municipal Code Ch. 9.10 Noise Control

Footnotes:

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Editor's note— Ord. No. 2009-380, § 1, adopted July 22, 2009, amended chapter 9.10 in its entirety to read as herein set out. Former chapter 9.10, §§ 9.10.010—9.10.030, pertained to similar subject matter, and derived from Ord. 1997-296 § 1(part), adopted 1997; and Ord. 2002-296 §§ 1 and 2(part), adopted 2002.

It is the policy of the town to protect its citizens from the harmful and annoving effects of excessive noise. This chapter is established to implement the noise element of the general plan and to regulate and control disturbing, excessive and offensive noise. The town encourages efforts by residents to address noise issues amicably through direct communication with their neighbors.

(Ord. 2009-380 § 1, 2009)

[The following words, terms and phrases, when used in this chapter, shall have the meanings ascribed to them in this section, except where the context clearly indicates a different meaning:]

"Ambient noise" means the composite of noise from all sources near and far. In this context, the ambient noise level constitutes the normal or existing level of environmental noise at a given location.

"A-weighted sound level (dBA)" means the sound pressure level in decibels as measured on a sound level meter using the A-weighted network. The A-weighting filter de-emphasizes the very low and very high frequency components of the sound in a manner similar to the response of the human ear and gives a good correlation with subjective reactions to noise. Also referred to in this chapter as simply "sound level".

"Construction, grading and clearing" means construction, demolition, or repair work on any building, structure, foundation, vegetation or project, which activities include, but are not limited to: The use of any mechanically powered saw, sander, drill, grinder, pneumatic jack hammer, electric jack hammer, chain saw, steam or electric hoist, hydraulic drill or shovel, "bob-cat", backhoe, bulldozer, dump truck, or other construction device; grading; clearing of land; delivery or removal of construction materials; or movement of construction materials from place to place on a site.

"Decibel (dB)" means a unit for measuring the volume of a sound.

"Demolition" means any dismantling, intentional destruction or removal of structures, utilities, public or private right-of-way surfaces, or property.

"Domestic garden tools" means leaf blowers, weed whackers, lawn mowers, chippers, chain saws, or any other lawn or garden power tool.

"Emergency" means any occurrence or set of circumstances involving actual or imminent physical trauma or property damage which demands immediate actions.

"Equivalent A-weighted sound level (L eg )" means the sound level containing the same total energy as a time varying signal over a given sample period, typically one hour.

"Holidays" mean January 1 st , Martin Luther King, Jr. Day, President's Day, Memorial Day, July 4 th , Labor Day, Veteran's Day, Thanksgiving and Christmas. If any holiday falls on a Sunday, the next Monday shall be considered a holiday.

"Impulsive sound" means sound of short duration, usually less than one second, with an abrupt onset and rapid decay, such as hammering.

"Maximum sound level (l max )" means the maximum sound level recorded during a noise event. To measure a constant sound, the "slow" sound level meter time constant setting shall be used; if the sound is impulsive, the "fast" setting shall be used.

"Noise" means any sound that annoys or disturbs a reasonable person of normal sensitivities.

"Noise sensitive land use" means locations where there are greater sensitivities to excess noise including, but not limited to, residences, hospitals, nursing homes, theaters, auditoriums, religious facilities, meeting halls, schools, libraries, museums and parks.

"Non-transportation noise source" means any source of noise that emanates from a particular fixed location. Examples include machinery, equipment, loudspeakers, truck loading areas, parking and waiting areas and places of entertainment.

"Tonal sound" means a sound that can be distinctly heard as a single pitch usually characterized by a whine, screech or hum.

"Transportation noise source" means any source of noise that emanates from vehicles in motion either associated with ground transportation (roadway) or with air traffic (airplane and helicopter).

(Ord. 2009-380 § 1, 2009)

It is unlawful for any person in any location in the town from the effective date of this chapter to create or cause to be created any noise that exposes properties in the vicinity to noise levels that exceed the levels indicated in Table 9.10-1, provided that, if the noise is generated by a structure or integral part of a structure, such compliance is required within twelve months after the effective date of the ordinance, August 21, 2009. Noises permitted by Sections 9.10.040 and 9.10.070 are not subject to Table 9.10-1.

Table 9.10-1 Non-Transportation Generated Noise Standards

(Ord. 2009-380 § 1, 2009)

No person shall do, cause or suffer or permit to be done on any premises owned, occupied or controlled by such a person, any of the following acts except as provided below. All vehicles, equipment and machines associated with the enumerated activities shall incorporate design features in good operating order that meet current industry standards for noise muffling and noise reduction. Permitted sources of noise described in this section shall be subject to applicable conditional use permit conditions, construction program agreements, town noise reduction guidelines, and other forms of regulation.

A. Construction Activities. Commercial construction activities may take place between eight a.m. and five-thirty p.m., Monday through Friday. Any resident may personally (including with the help of immediate family members) undertake construction activities during the following hours: Monday through Friday between eight a.m. and five-thirty p.m. and Saturday and Sunday between ten a.m. and five p.m. Commercial and resident construction activities are prohibited on holidays. Exceptions to these hours may be permitted in unusual circumstances pursuant to written authorization from the director of public works. No radios or other amplified sound devices shall be audible beyond the property line of the construction site.

B. Domestic Garden Tools. Domestic garden tools, including electric-powered leaf blowers, may be used by commercial companies only Monday through Friday between eight a.m. and five-thirty p.m. and Saturday between ten a.m. and five p.m.; provided that chippers and chain saws may not be used on Saturday. Any resident may personally (including with the help of immediate family members) use domestic garden tools during the following hours: Monday through Friday between eight a.m. and five-thirty p.m. and Saturday and Sunday between ten a.m. and five p.m. Domestic garden tools may be used by property owners only for the purpose of removing seasonal grasses and plant materials that pose a fire hazard on all days, except holidays, between eight a.m. and eight p.m. from April 15 to June 15; however, this provision does not allow the use of chain saws and chippers on Sundays. The commercial and resident use of domestic garden tools is prohibited on holidays.

C. Large Vehicle Delivery and Loading. For other than construction activities, the loading, unloading or delivery of goods, merchandise, vehicles or supplies by large trucks, tractor-trailers, or other similar vehicles is restricted to the hours between eight a.m. and five-thirty p.m., Monday through Friday, unless otherwise authorized by a conditional use permit.

D. Garbage Collection. Collection of garbage and other refuse is restricted to the hours between eight a.m. and five p.m., Monday through Friday, unless authorized otherwise by a franchise agreement with the town.

E. Residential Emergency Generators. The testing of home generators used for emergency power is permitted only on weekdays, no more frequently than once a week and for a duration not exceeding twenty minutes restricted to the hours between ten a.m. and four p.m. Home generators shall not be tested on holidays. Home generators shall not produce a sound exceeding sixty-five dBA when measured twenty-two feet from the generator, and shall have mufflers and generator enclosures in good condition and appropriate for the generator. Emergency generators shall be located as far as possible from adjoining properties.

(Ord. 2019-427, § 1, 2019; Ord. 2009-380 § 1, 2009)

While the noise standards in this chapter are consistent with generally accepted community noise limitations, there may be circumstances where the standards do not reduce noise from non-transportation noise sources to a level appropriate for the use and the surrounding area. In such instances, and where the noise generator is controlled by a conditional use permit, the conditional use permit may establish conditions for such use to achieve noise levels that are lower than the standards in this chapter.

(Ord. 2009-380 § 1, 2009)

Notwithstanding any other provision of this chapter, the following sources of noise are prohibited:

A. Animals and Fowl. The keeping of any animal, including but not limited to, dogs, fowl and crowing roosters, which by any persistent sound or cry disturbs a reasonable person owning, using, or occupying property in the neighborhood.

B. Sounding Horns and Signal Devices. The sounding of any horn or signal device on any automobile, motorcycle, bus, or other vehicle in any other manner or circumstance or of any other purpose than required or permitted by the California Vehicle Code or other laws of the state.

C. Racing Engine. The racing of an engine of any motor vehicle, except when necessary to do so in the course of repairing, adjusting or testing but not so that a reasonable person owning, using or occupying property in the neighborhood is disturbed.

D. Musical Instruments, Sound Amplifiers and Sounds in General. The making of any recurring and excessive sound or noise by any method so that the sound is plainly audible and a reasonable person owning, using, or occupying property in the neighborhood is disturbed. This prohibition includes, but is not limited to, the use or operation of any musical instrument or any device, machine, apparatus, or instrument for intensification or amplification of the human voice or music.

E. Outdoor Amplified Sound on Town Property. The use of amplified sound outdoors on property owned by the town for any purpose unless authorized in writing by the town.

F. Explosives, Firearms, and Similar Devices. The use or firing of explosives, firearms, or similar devices which create impulsive sound so as to cause a noise disturbance across a real property boundary or on a public space or right-of-way, except when part of a government-authorized honor guard.

G. Motor Vehicle Maintenance. Work on motor vehicles, at other than service facilities approved by the town, that is plainly audible and a reasonable person owning, using, or occupying property in the neighborhood is disturbed.

H. Leaf Blowers. Leaf blowers shall not produce a sound that exceeds sixty-five dBA when measured from a distance of fifty feet utilizing American National Standard Institute methodology. No person shall operate any leaf blower which does not bear an affixed manufacturer's label indicating the model number of the leaf blower and designating a noise level not in excess of sixty-five dBA. Any leaf blower that bears such a manufacturer's label shall be presumed to comply with any noise level limit of this chapter provided that it is operated with all mufflers and full extension tubes supplied by the manufacturer for that leaf blower. No person shall operate any leaf blower without attachment of all mufflers and full extension tubes supplied by the manufacturer for that leaf blower. This requirement becomes effective one year after the adoption of this revised chapter.

I. Gas-Powered Leaf Blowers. Notwithstanding the prohibition against gas-powered leaf blowers in Section 8.32, such leaf blowers will be permitted for emergency use if authorized by the town manager in writing for a specified duration.

(Ord. 2019-427, § 1, 2019; Ord. 2009-380 § 1, 2009)

Sound or noise emanating from the following sources and activities are exempt from the provisions of this ordinance:

A. Emergencies involving the execution of the duties of duly authorized governmental personnel and others providing emergency response to the general public including, but not limited to, sworn peace officers, emergency personnel, utility personnel, and the operation of emergency response vehicles and equipment.

B. Emergencies that pose a threat to property or safety of persons or animals and require action by a resident, including with the help of immediate family members or a commercial company.

C. Safety, warning and alarm devices, including house and car alarms, and other warning devices that are designed to protect the health, safety, and welfare, provided such devices are well-maintained, and designed with automatic shutoffs or a direct connection to a security service, both of which turn off the device after a reasonable time limit.

D. Gas-powered devices may be used in emergency situations and/or as needed for major storm cleanup, creekside maintenance, prevention of traffic obstructions and other health or safety reasons as authorized by the town manager in writing for a specified duration. The town manager has the authority to adopt regulations implementing this exception.

E. Graduation ceremonies at the town's public and private schools.

F. Opening day and championship sports games, not to exceed three weekends a year.

(Ord. 2019-427, § 1, 2019; Ord. 2009-380 § 1, 2009; Ord. No. 2021-440, § 1, 2021)

Noises not addressed in the chapter shall adhere to the most relevant provisions in the ordinance as determined by town staff or on referral to the town council.

(Ord. 2009-380 § 1, 2009)

TITLE 9 FOOTNOTES

1. Editor's Note: County code provisions adopted by reference are on file in the town clerk's office.