Chapter 18.21
PERFORMANCE STANDARDS Revised 1/24

Sections:

18.21.010    Purpose.

18.21.020    Applicability.

18.21.030    General standard.

18.21.040    Location of measurement for determining compliance.

18.21.050    Noise. Revised 1/24

18.21.060    Vibration.

18.21.070    Odors.

18.21.080    Heat and humidity.

18.21.090    Air contaminants.

18.21.100    Liquid or solid waste.

18.21.110    Fire and explosive hazards.

18.21.120    Hazardous and extremely hazardous materials.

18.21.130    Electromagnetic interference.

18.21.140    Radioactivity.

18.21.150    San Carlos Airport land use compatibility plan consistency. Revised 1/24

18.21.010 Purpose.

The purposes of this chapter are to:

A.    Establish permissible limits and permit objective measurement of nuisances, hazards, and objectionable conditions;

B.    Ensure that all uses will provide necessary control measures to protect the community from nuisances, hazards, and objectionable conditions;

C.    Protect industry from arbitrary exclusion from areas of the City; and

D.    Protect and sustain the natural environment by promoting conservation of energy and natural resources, improving waste stream management, and reducing emission of greenhouse gases. (Ord. 1438 § 4 (Exh. A (part)), 2011)

18.21.020 Applicability.

The minimum requirements in this chapter apply to all land uses in all zoning districts, unless otherwise specified. (Ord. 1438 § 4 (Exh. A (part)), 2011)

18.21.030 General standard.

Land or buildings shall not be used or occupied in a manner creating any dangerous, injurious, or noxious fire, explosive or other hazard that would adversely affect the surrounding area. (Ord. 1438 § 4 (Exh. A (part)), 2011)

18.21.040 Location of measurement for determining compliance.

Measurements necessary for determining compliance with the standards of this chapter shall be taken at the lot line of the establishment or use that is the source of a potentially objectionable condition, hazard, or nuisance. (Ord. 1438 § 4 (Exh. A (part)), 2011)

18.21.050 Noise. Revised 1/24

A.    Noise Limits. No use or activity shall create noise levels that exceed the following standards. The maximum allowable noise levels specified in Table 18.21.050-A, Noise Limits, do not apply to noise generated by automobile traffic or other mobile noise sources in the public right-of-way.

 

TABLE 18.21.050-A: NOISE LIMITS

Land Use Receiving the Noise

Noise-Level Descriptor

Exterior Noise Level Standard in Any Hour (dBA)

Interior Noise-Level Standard in Any Hour (dBA)

Daytime (7 a.m. – 10 p.m.)

Nighttime (10 p.m. – 7 a.m.)

Daytime (7 a.m. – 10 p.m.)

Nighttime (10 p.m. – 7 a.m.)

Residential

L50

55

45

40

30

Lmax

70

60

55

45

Medical, convalescent

L50

55

45

45

35

Lmax

70

60

55

45

Theater, auditorium

L50

-

-

35

35

Lmax

-

-

50

50

Church, meeting hall

L50

55

-

40

40

Lmax

-

-

55

55

School, library, museum

L50

55

-

40

-

Lmax

-

-

55

-

1.    Adjustments to Noise Limits. The maximum allowable noise levels of Table 18.21.050-A, Noise Limits, shall be adjusted according to the following provisions. No more than one increase in the maximum permissible noise level shall be applied to the noise generated on each property.

a.    Ambient Noise. If the ambient noise level at a noise-sensitive use is ten dBA or more below the standard, the allowable noise standard shall be decreased by five decibels.

b.    Duration. The maximum allowable noise level (L50) shall be increased as follows to account for the effects of duration:

i.    Noise that is produced for no more than a cumulative period of fifteen minutes in any hour may exceed the noise limit by five decibels; and

ii.    Noise that is produced for no more than a cumulative period of five minutes in any hour may exceed the noise limits by ten decibels;

iii.    Noise that is produced for no more than a cumulative period of one minute in any hour may exceed the noise limits by fifteen decibels.

c.    Character of Sound. If a noise contains a steady audible tone or is a repetitive noise (such as hammering or riveting) or contains music or speech conveying informational content, the maximum allowable noise levels shall be reduced by five decibels.

d.    Prohibited Noise. Noise for a cumulative period of thirty minutes or more in any hour which exceeds the noise standard for the receiving land use.

B.    Noise Exposure—Land Use Requirements and Limitations. Table 18.21.050-B, Noise Exposure—Land Requirements and Limitations, describes the requirements and limitations of various land uses within the listed day/night average sound level (Ldn) ranges.

 

TABLE 18.21.050-B: NOISE EXPOSURE—LAND USE REQUIREMENTS AND LIMITATIONS

Land Use

Day/Night Average Sound Level (Ldn)

Requirements and Limitations

Residential (1) and Other Noise-Sensitive Uses (e.g., Schools, Hospitals, and Churches)

Less than 60

Satisfactory

60 to 75

Acoustic study and noise attenuation measures required

Over 75

Acoustic study and noise attenuation measures required

Auditoriums, Concert Halls, Amphitheaters

Less than 70

Acoustic study and noise attenuation measures required

Over 70

Not allowed

Commercial and Industrial

Less than 70

Satisfactory

70 to 80

Acoustic study and noise attenuation measures required

Over 80

Airport-related development only; noise attenuation measures required

Outdoor Sports and Recreation, Parks

Less than 65

Satisfactory

65 to 80

Acoustic study and noise attenuation measures required; avoid uses involving concentrations of people or animals

Over 80

Limited to open space; avoid uses involving concentrations of people or animals

Notes:

1.    New residential development in noise impacted areas are subject to the following noise levels:

a.    For new single-unit residential development, maintain a standard of 60 Ldn for exterior noise in private use areas.

b.    For new multi-unit residential development, maintain a standard of 65 Ldn in community outdoor recreation areas. Noise standards are not applied to private decks and balconies and shall be considered on a case-by-case basis in the MU-DC District.

c.    Where new residential units (single and multifamily) would be exposed to intermittent noise levels generated during train operations, maximum railroad noise levels inside homes shall not exceed forty-five dBA in bedrooms or fifty-five dBA in other occupied spaces. These single-event limits are only applicable where there are normally four or more train operations per day.

C.    Acoustic Study. The Director may require an acoustic study for any proposed project that could cause any of the following:

1.    Create an inconsistency with the noise requirements of the San Carlos Airport as defined in Section 18.21.150, San Carlos Airport land use compatibility plan consistency;

a.    Where applicable, noise attenuation measures may be required;

2.    Cause noise levels to exceed the limits in Table 18.21.050-A;

3.    Create a noise exposure that would require an acoustic study and noise attenuation measures listed in Table 18.21.050-B, Noise Exposure—Land Use Requirements and Limitations; or

4.    Cause the Ldn at noise-sensitive uses to increase three dBA or more.

D.    Establishing Ambient Noise. When the Director has determined that there could be cause to make adjustments to the standards, an acoustical study shall be performed to establish ambient noise levels. In order to determine if adjustments to the standards should be made either upwards or downwards, a minimum twenty-four-hour-duration noise measurement shall be conducted. The noise measurements shall collect data utilizing noise metrics that are consistent with the noise limits presented in Table 18.21.050-A, e.g., Lmax (zero minutes), L02 (one minute), L08 (five minutes), L25 (fifteen minutes) and L50 (thirty minutes). An arithmetic average of these ambient noise levels during the three quietest hours shall be made to demonstrate that the ambient noise levels are regularly ten or more decibels below the respective noise standards. Similarly, an arithmetic average of ambient noise levels during the three loudest hours should be made to demonstrate that ambient noise levels regularly exceed the noise standards.

E.    Noise Attenuation Measures. Any project subject to the acoustic study requirements of subsection C of this section may be required as a condition of approval to incorporate noise attenuation measures deemed necessary to ensure that noise standards are not exceeded.

1.    New noise-sensitive uses (e.g., schools, hospitals, churches, and residences) shall incorporate noise attenuation measures to achieve and maintain an interior noise level of forty-five dBA.

2.    Noise attenuation measures identified in an acoustic study shall be incorporated into the project to reduce noise impacts to satisfactory levels.

3.    Emphasis shall be placed upon site planning and project design measures. The use of noise barriers shall be considered and may be required only after all feasible design-related noise measures have been incorporated into the project.

F.    Airport Land Use Compatibility Plan Consistency. Where required, conformance with applicable airport land use compatibility plan standards, as described in Section 18.21.150, San Carlos Airport land use compatibility plan consistency, is required. (Ord. 1606 (Exh. A), 2023; Ord. 1438 § 4 (Exh. A (part)), 2011)

18.21.060 Vibration.

No vibration shall be produced that is transmitted through the ground and is discernible without the aid of instruments by a reasonable person at the lot lines of the site. Vibrations from temporary construction, demolition, and vehicles that enter and leave the subject parcel (e.g., construction equipment, trains, trucks, etc.) are exempt from this standard. (Ord. 1438 § 4 (Exh. A (part)), 2011)

18.21.070 Odors.

No use, process, or activity shall produce objectionable odors that are perceptible without instruments by a reasonable person at the lot lines of a site. Odors from temporary construction, demolition, and vehicles that enter and leave the site (e.g., construction equipment, trains, trucks, etc.) are exempt from this standard. (Ord. 1438 § 4 (Exh. A (part)), 2011)

18.21.080 Heat and humidity.

Uses, activities, and processes shall not produce any emissions of heat or humidity that cause distress, physical discomfort, or injury to a reasonable person, or interfere with ability to perform work tasks or conduct other customary activities. In no case shall heat emitted by a use cause a temperature increase in excess of five degrees Fahrenheit on another property. (Ord. 1438 § 4 (Exh. A (part)), 2011)

18.21.090 Air contaminants.

A.    General Standards. Uses, activities, and processes shall not operate in a manner that emits excessive dust, fumes, smoke, or particulate matter, excluding standards set under State and Federal law.

B.    Compliance. Sources of air pollution shall comply with all rules established by the Environmental Protection Agency (Code of Federal Regulations, Title 40), the California Air Resources Board, and the Bay Area Air Quality Management District (BAAQMD).

C.    BAAQMD Permit. Operators of activities, processes, or uses that require approval to operate from the BAAQMD shall file a copy of the permit with the Planning Division within thirty days of permit approval. Ord. 1480 (Exh. C (part)), 2015; (Ord. 1438 § 4 (Exh. A (part)), 2011)

18.21.100 Liquid or solid waste.

A.    Discharges to Water or Sewers. Liquids and solids of any kind shall not be discharged, either directly or indirectly, into a public or private body of water, sewage system, watercourse, or into the ground, except in compliance with applicable regulations of the California Regional Water Quality Control Board (California Administrative Code, Title 23, Chapter 3 and California Water Code, Division 7).

B.    Solid Wastes. Solid wastes shall be handled and stored so as to prevent nuisances, health, safety and fire hazards, and to facilitate recycling. There shall be no accumulation outdoors of solid wastes conducive to the breeding of rodents or insects, unless stored in closed containers. (Ord. 1480 (Exh. C (part)), 2015: Ord. 1438 § 4 (Exh. A (part)), 2011)

18.21.110 Fire and explosive hazards.

All activities, processes and uses involving the use of, or storage of, flammable and explosive materials shall be provided with adequate safety devices against the hazard of fire and explosion. Fire fighting and fire suppression equipment and devices standard in industry shall be approved by the Fire Department. All incineration is prohibited with the exception of those substances such as, but not limited to, chemicals, insecticides, hospital materials and waste products, required by law to be disposed of by burning, and those instances wherein the Fire Department deems it a practical necessity. (Ord. 1480 (Exh. C (part)), 2015: Ord. 1438 § 4 (Exh. A (part)), 2011)

18.21.120 Hazardous and extremely hazardous materials.

The use, handling, storage and transportation of hazardous and extremely hazardous materials shall comply with the provisions of the California Hazardous Materials Regulations and the California Fire and Building Codes, as well as the laws and regulations of the California Department of Toxic Substances Control and the County Environmental Health Agency. Activities, processes, and uses shall not generate or emit any fissionable or radioactive materials into the atmosphere, a sewage system or onto the ground. (Ord. 1480 (Exh. C (part)), 2015: Ord. 1438 § 4 (Exh. A (part)), 2011)

18.21.130 Electromagnetic interference.

No use, activity or process shall cause electromagnetic interference with normal radio and television reception in any residential district, or with the function of other electronic equipment beyond the lot line of the site in which it is situated. All uses, activities and processes shall comply with applicable Federal Communications Commission regulations. (Ord. 1438 § 4 (Exh. A (part)), 2011)

18.21.140 Radioactivity.

No radiation of any kind shall be emitted that is dangerous to humans. (Ord. 1438 § 4 (Exh. A (part)), 2011)

18.21.150 San Carlos Airport land use compatibility plan consistency. Revised 1/24

This section establishes standards and requirements related to consistency within the County of San Mateo’s Comprehensive Airport Land Use Compatibility Plan for the Environs of San Carlos Airport (ALUCP). The ALUCP outlines the following requirements and criteria for proposed development projects, alterations, or changes of use that are subject to the ALUCP:

A.    Safety Compatibility Evaluation. All proposed development projects, alterations, or changes of use subject to the ALUCP will be reviewed for consistency with the County of San Mateo’s Safety Compatibility Policies of the ALUCP. Project applicants shall be required to evaluate potential safety issues if the property is located within any of the safety compatibility zones established in the ALUCP.

B.    Airspace Protection Evaluation. All proposed development projects, alterations, or changes of use subject to the ALUCP will be reviewed for consistency with Airspace Protection Policies of the ALUCP. These include notice of proposed construction or alteration, maximum compatible building height and other flight hazards and avigation easement requirements of San Carlos ALUCP Airspace Protection Policy 7.

C.    Airport Noise Evaluation and Mitigation. All proposed development projects, alterations, or changes of use subject to the ALUCP will be reviewed for consistency with the noise policies of the ALUCP, including the avigation easement requirements of San Carlos ALUCP Noise Policy 7. Uses listed as “conditionally compatible” in the ALUCP will be required to mitigate impacts to comply with the interior noise standards established in the ALUCP or General Plan, whichever is more restrictive.

D.    Airport Real Estate Disclosure Notices. Proximity to the airport could affect allowable development and uses. All proposed developments, alterations, or changes of use that are subject to the ALUCP are required to comply with the real estate disclosure requirements of State law (California Business and Professions Code Section 11010(b)(13)). The following statement by the seller must be included in the notice of intention to offer the property for sale or lease:

Notice of Airport in Vicinity. This property is presently located in the vicinity of an airport, within what is known as an airport influence area. For that reason, the property may be subject to some of the annoyances or inconveniences associated with proximity to airport operations (for example: noise, vibration, or odors). Individual sensitivities to those annoyances can vary from person to person. You may wish to consider what airport annoyances, if any, are associated with the property before you complete your purchase and determine whether they are acceptable to you.

E.    Overflight Notification Requirement. All new residential development projects, other than additions and accessory dwelling units (ADUs), within Overflight Notification Zone 2 shall incorporate a recorded overflight notification requirement as a condition of approval in order to provide a permanent form of overflight notification to all future property owners, consistent with ALUCP Overflight Policies.

F.    Federal Aviation Administration (FAA) Requirements. Proof of consistency with FAA rules and regulations must be provided through one (1) of the following ways:

1.    A Federal Aviation Administration Review Not Required Form must be signed prior to issuance of building permit.

2.    Receive a determination of no hazard by the FAA after submittal of FAA Form 7460-1, Notice of Proposed Construction. Instructions and additional information on Form 7460 can found within the ALUCP and on the FAA’s website.

G.    Local Agency Override of an Airport Land Use Commission Determination. A process under which the City Council may overrule certain Airport Land Use Commission determinations under certain circumstances is established in Sections 21675.1(d), 21676(b) and 21676(c) of the Public Utilities Code and outlined in the ALUCP.

H.    Required Disclosures. In the event of local override action of an Airport Land Use Commission determination, disclosures may be required from property owners as a condition of approval for any use listed as conditional in the ALUCP noise or safety compatibility zone that corresponds with the site of the proposed project, including childcare, congregate care facilities, etc. Property owners are encouraged to provide appropriate notices to their tenants. (Ord. 1606 (Exh. A), 2023; Ord. 1438 § 4 (Exh. A (part)), 2011)