Chapter 18.21
PERFORMANCE STANDARDS

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.

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    Airspace protection.

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.

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.    Locate new residential uses within the fifty-five CNEL impact area of the San Carlos Airport;

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. (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 Airspace protection.

The following applies within airport influence area (AIA) B as adopted by the San Mateo County Airport Land Use Commission and subsequent revisions thereto, for the environs of San Carlos Airport.

A.    Federal Airspace Protection Surfaces. Maximum height of structures shall not penetrate the civil airport imaginary surfaces as defined by the Federal Aviation Administration in (FAA) Title 14 CFR Part 77, Surfaces.

B.    Flight Hazards. Proposed land use actions that include land uses that may cause visual, electronic, or wildlife hazards may be permitted only if the uses are consistent with FAA rules and regulations. Proof of consistency with FAA rules and regulations must be provided to the Airport Land Use Commission by the sponsor of the proposed land use action. Specific characteristics that may create hazards to aircraft in flight and which shall be prohibited include:

1.    Sources of glare, such as highly reflective buildings or building features, or bright light, including searchlights or laser displays, which would interfere with the vision of pilots;

2.    Distracting lights that could be mistaken for airport identification lighting, runway edge lighting, runway end identification lighting, or runway approach lighting;

3.    Sources of dust, smoke, water vapor, or steam that may impair visibility;

4.    Sources of electrical interference with aircraft communications or navigation equipment;

5.    Any use that creates an increased attraction for wildlife, particularly large flocks of birds, that is inconsistent with FAA rules and regulations. (Ord. 1438 § 4 (Exh. A (part)), 2011)