San Luis Obispo County, CA Noise Ordinance
(NPC posted this March 2004)



23.06.040 - Noise Standards:

Sections 23.06.044-050 establish standards for acceptable exterior and interior noise levels and describe how noise is to be measured. These standards are intended to protect persons from excessive noise levels, which are detrimental to the public health, welfare and safety and contrary to the public interest because they can: interfere with sleep, communication, relaxation and the full enjoyment of one's property; contribute to hearing impairment and a wide range of adverse physiological stress conditions; and adversely affect the value of real property. It is the intent of this chapter to protect persons from excessive levels of noise within or near various residential development and other specified noise-sensitive land uses.

[Amended 1992, Ord. 2546]

23.06.042 - Exceptions to Noise Standards:

The standards of Sections 23.06.044-050 are not applicable to noise from the following sources:

a. Activities conducted in public parks, public playgrounds and public or private school grounds, including but not limited to school athletic and school entertainment events;

b. The use of any mechanical device, apparatus or equipment related to or connected with emergency activities or emergency work to protect life or property;

c. Safety signals, warning devices, and emergency pressure relief valves;

d. Noise sources associated with construction, provided such activities do not take place before seven a.m. or after nine p.m. any day except Saturday or Sunday, or before eight a.m. or after five p.m. on Saturday or Sunday;

e. Noise sources associated with the maintenance of a residential use as listed in Table O, Framework for Planning of the Land Use Element and Local Coastal Plan, provided that such activities take place between the hours of seven a.m. and nine p.m.;

f. Noise sources associated with agricultural land uses as listed in Table O, Framework for Planning of the Land Use Element and Local Coastal Plan, including but not limited to wind machines used for direct climate control, water well pumps and pest-repelling devices, provided that such pest-repelling devices are used in accordance with accepted standards and practices;

g. Noise sources associated with a lawful use which is other than a residential use as listed in Table O, Framework for Planning of the Land Use Element and Local Coastal Plan, caused by mechanical devices or equipment, including air conditioning or refrigeration systems, installed prior to the effective date of this chapter; this exemption shall expire one year after the effective date of this chapter;

h. Noise sources associated with work performed by private or public utilities in the maintenance or modification of its facilities;

i. Noise sources associated with the collection of waste or garbage from property devoted to other than residential uses listed in Table O, Framework for Planning of the Land Use Element and Local Coastal Plan.

j. Traffic on public roadways, railroad line operations, aircraft in flight, and any other activity to the extent regulation thereof has been preempted by state or federal law.

[Amended 1992, Ord. 2546; 1993, Ord. 2591; 1995, Ord. 2715]

23.06.044 - Exterior Noise Level Standards:

The exterior noise level standards of this section are applicable when a land use affected by noise is one of the following noise-sensitive uses which are defined in the Land Use Element and Local Coastal Plan: residential uses listed in Table O, Framework for Planning, except for residential accessory uses and temporary dwellings; health care services (hospitals and similar establishments only); hotels and motels; bed and breakfast facilities; schools (pre-school to secondary, college and university, specialized education and training); churches; libraries and museums; public assembly and entertainment; offices, and outdoor sports and recreation.

a. No person shall create any noise or allow the creation of any noise at any location within the unincorporated areas of the county on property owned, leased, occupied or otherwise controlled by such person which causes the exterior noise level when measured at any of the preceding noise-sensitive land uses situated in either the incorporated or unincorporated areas to exceed the noise level standards in the following table. When the receiving noise-sensitive land use is outdoor sports and recreation, the following noise level standards shall be increased by 10dB.
EXTERIOR NOISE LEVEL STANDARDS
  Daytime
(7 a.m. to 10 p.m.)
Nighttime1
(10 p.m. to 7 a.m.)
Hourly Equivalent Sound Level (Leq, dB) 50 45
Maximum level, dB 70 65

1. Applies only to uses that operate or are occupied during nighttime hours

b. In the event the measured ambient noise level exceeds the applicable exterior noise level standard in subsection (a), the applicable standard shall be adjusted so as to equal the ambient noise level plus one dB.
c. Each of the exterior noise level standards specified in subsection (a) shall be reduced by five dB for simple tone noises, noises consisting primarily of speech or music, or for recurring impulsive noises.
d. If the intruding noise source is continuous and cannot reasonably be discontinued or stopped for a time period whereby the ambient noise level can be measured, the noise level measured while the source is in operation shall be compared directly to the exterior noise level standards.

[Amended 1992, Ord. 2546]

23.06.046 - Interior Noise Level Standards:

The interior noise level standards of this section are applicable when the land use which is the source of noise and the land use which is affected by noise are both residential uses as listed in Table O, Framework for Planning of the Land Use Element and Local Coastal Plan, except for residential accessory uses and temporary dwellings.

a. No person shall operate or cause to be operated a source of noise within a residential use in any location in the unincorporated areas of the county or allow the creation of any noise which causes the noise level when measured inside a residential use located in either the incorporated or unincorporated area to exceed the interior noise level standards in the following table:
INTERIOR NOISE LEVEL STANDARDS
  Daytime
(7 a.m. to 10 p.m.)
Nighttime
(10 p.m. to 7 a.m.)
Hourly Equivalent Sound Level (Leq, dB) 40 35
Maximum level, dB 60 55
b. In the event the measured ambient noise level exceeds the applicable interior noise level standard in subsection (a), the applicable standard shall be adjusted so as to equal the ambient noise level plus one dB.
c. Each of the interior noise level standards specified in subsection (a) shall be reduced by five dB for simple tone noises, noises consisting primarily of speech or music, or for recurring impulsive noises.
d. If the intruding noise source is continuous and cannot reasonably be discontinued or stopped for a time period whereby the ambient noise level can be measured, the noise level measured while the source is in operation shall be compared directly to the interior noise level standards.

[Added 1992, Ord. 2546]

23.06.048 - Other Noise Sources:

The noise level standards in this section apply to the following noise sources:

a. Air conditioning and refrigeration: Notwithstanding the provisions of Section 23.06.044, when the intruding noise source is an air conditioning or refrigeration system or associated equipment installed prior to the effective date of this chapter, the exterior noise level as measured as provided in Section 23.06.050 shall not exceed 55 dB, except where such equipment is exempt from the provisions of this chapter. The exterior noise level shall not exceed fifty dB for such equipment installed or in use after one year after the effective date of this chapter.
b. Waste and garbage collection equipment: Notwithstanding the provisions of Section 23.06.044, noise sources associated with the collection of waste or garbage from a residential use (as listed in Table O, Framework for Planning of the Land Use Element and Local Coastal Plan) by persons authorized to engage in such activity, and who are operating truck-mounted loading or compacting equipment, shall not take place before seven a.m. or after seven p.m., and the noise level created by such activities when measured at a distance of fifty feet (50) in an open area shall not exceed the following standards:
(1) Eighty-five (85) dB for equipment in use, purchased or leased within six months from the effective date of this chapter.
(2) Eighty (80) dB for that equipment set forth in subsection a(l) after five years from the effective date of this chapter.
(3) Eighty (80) dB for new equipment purchased or leased after six months from the effective date of this chapter.
(4) Seventy-five (75) dB for new equipment purchased or leased after thirty-six months from the effective date of this chapter.
c. Electrical substations: Notwithstanding the provisions of Section 23.06.044, noise sources associated with the operation of the following electrical substations shall not exceed an exterior noise level of fifty dB between 10 p.m. and 7 a.m. and fifty-five dB between 7 a.m. and 10 p.m., as determined at the property line of the receiving land use: theCholame, San Miguel, Templeton, Cambria, Perry, Cayucos, Baywood, Highway 1 between Morro Bay and the California Men's Colony, Goldtree, Foothill, San Luis Obispo, Oceano, Mesa, Union Oil, Callendar, and Mustang electrical substations. If any of these existing electrical substations undergo modifications that increase noise levels, they shall be mitigated in accordance with the policies of the Noise Element Document.

[Added 1992, Ord. 2546]

23.06.050 - Noise Level Measurement:

For the purpose of evaluating conformance with the standards of this chapter, noise levels shall be measured as follows:

a. Use of meter: Any noise measurement made pursuant to the provisions of Sections 23.06.044-048 shall be made with a sound level meter using the A-weighted network (scale). Calibration of the measurement equipment utilizing an acoustical calibrator shall be performed immediately prior to recording any noise data.
b. Measuring exterior noise levels: Except as otherwise provided in Sections 22.06.044-048, exterior noise levels shall be measured at the property line of the affected noise-sensitive land use listed in Section 23.06.044. Where practical, the microphone shall be positioned five feet above the ground and away from reflective surfaces.
c. Measuring interior noise levels: Interior noise levels shall be measured within the affected residential use listed in Section 23.06.046, at points at least four (4) feet from the wall, ceiling or floor nearest the noise source, with windows in the normal seasonal configuration. The reported interior noise level shall be determined by taking the arithmetic average of the readings taken at the various microphone locations.

[Added 1992, Ord. 2546]