500.05: REGULATIONS FOR NOISE EXPOSURE: — Porterville Zoning Code

A. Noise Exposure; Compatibility Criteria: In regard to noise exposure levels, land uses are classified as being either "normally compatible", "conditional" or "incompatible" as defined below. All land uses are compatible at noise exposure less than CNEL fifty five (55) dB.

Normally compatible:

a. Indoor Uses: Either the activities associated with the land use are inherently noisy or standard construction methods will sufficiently attenuate exterior noise to an acceptable indoor community noise equivalent level (CNEL); for land use types that are compatible because of inherent noise levels, sound attenuation must be provided for associated office, retail, and other noise sensitive indoor spaces sufficient to reduce exterior noise to an interior maximum of CNEL fifty (50) dB.

b. Outdoor Uses: Except as noted in the table, activities associated with the land use may be carried out with minimal interference from aircraft noise.

Conditional:

a. Indoor Uses: Building structure must be capable of attenuating exterior noise to the indoor CNEL indicated by the number in the table cell.

b. Outdoor Uses: Caution shall be exercised with regard to noise sensitive outdoor uses; these uses are likely to be disrupted by aircraft noise events; acceptability is dependent upon characteristics of the specific use. Noise sensitive land uses are ones for which the associated primary activities, whether indoor or outdoor, are susceptible to disruption by loud noise events. The most common types of noise sensitive land uses include, but are not limited to, the following: residential,

hospitals, nursing facilities, intermediate care facilities, educational facilities, libraries, museums, places of worship, childcare facilities, and certain types of passive recreational parks and open space.

Incompatible:

a. Indoor Uses: Unacceptable noise interference if windows are open; at exposures above CNEL sixty five (65) dB, extensive mitigation techniques required to make the indoor environment acceptable for performance of activities associated with the land use.

b. Outdoor Uses: Severe noise interference makes the outdoor environment unacceptable for performance of activities associated with the land use.

B. Noise Exposure; Land Use Compatibility: Table 500.05B of this section describes the compatibility of various land uses within the noise impact zones as shown in section 500.10, map 500-1, "Airport Impact Map: Future Noise", of this article. Land uses not specifically listed in table 500.05B of this section shall be evaluated by the zoning administrator based on the criteria for the most similar comparable use.

The "conditional criteria" column lists the criteria to be met by uses listed as "conditional". The note numbers refer to criteria listed at the end of the table.

When a proposed building lies within multiple CNEL range zones (e.g., partly in 60 to 65 dB and partly in 65 to 70 dB), the higher range zone applies for the purposes of determining sound attenuation requirements unless less than twenty five percent (25%) of the building floor area is within that zone. In such case, the lower range zone may be used.

TABLE 500.05B: LAND USE COMPATIBILITY BY NOISE EXPOSURE LEVEL

NC =	NC =	C =	Conditional	Conditional			Incompatible

Land Use		Exterior Noise Exposure (CNEL dB)					Conditional Criteria

Land Use		Exterior Noise Exposure (CNEL dB)					Conditional Criteria
		55 - 60	60 - 65	65 - 70	70 - 75	75 - 80
Outdoor uses (limited or no activities in buildings):
	Natural land areas: woods, brush lands, desert	NC	NC	NC	NC	NC	See note 1
	Water: floodplains, wetlands, lakes, reservoirs	NC	NC	NC	NC	NC
	Agriculture (except residences and livestock): crops, orchards, vineyards, pasture, rangeland	NC	NC	NC	NC	NC
	Livestock uses: feedlots, stockyards, breeding, fish hatcheries, horse stables	C	C	C	C	I	See note 2
	Outdoor major assembly facilities (capacity 1,000 people): spectator oriented outdoor stadiums, amphitheaters, fairgrounds, zoos	C	C	C	I	I	See note 3
	Group recreation (limited spectator stands): athletic fields, water recreation facilities, picnic areas	NC	NC	C	I	I	See note 3
	Small/nongroup recreation: golf courses, tennis courts, shooting ranges	NC	C	C	I	I	See note 3
	Local parks: children oriented neighborhood parks, playgrounds	NC	C	I	I	I	See note 3
	Camping: campgrounds, recreational vehicle/motor home parks	NC	NC	I	I	I
	Cemeteries (excluding chapels)	NC	NC	NC	NC	I	See note 4
Residential and lodging uses:
	Single-family residential: individual dwellings, townhouses, mobile homes, bed and breakfast inns	C, 40	C, 40	I	I	I	See note 5
	Multi-family residential	C, 40	C, 40	I	I	I	See note 5
	Long term lodging (>30 nights): extended stay hotels, dormitories	NC	C, 45	I	I	I
	Short term lodging (30 nights): hotels, motels, other transient lodging (except conference/assembly facilities)	NC	C, 45	I	I	I
	Congregate care: retirement homes, assisted living, nursing homes, intermediate care facilities	NC	C, 45	I	I	I
Educational and institutional uses:
	Family daycare homes (14 children)	NC	I	I	I	I
	Children's schools: K - 12, daycare centers (>14 children); school libraries	NC	I	I	I	I
	Adult education classroom space: adult schools, colleges, universities	NC	C, 45	C, 45	I	I	See note 6

	Community libraries	NC	C, 45	I	I	I
	Indoor major assembly facilities (capacity 1,000 people): auditoriums, conference centers, concert halls, indoor arenas, casinos	NC	C, 45	C, 45	I	I
	Indoor large assembly facilities (capacity 300 to 999 people): movie theaters, places of worship, cemetery chapels, mortuaries	NC	C, 45	C, 45	I	I
	Indoor recreation: gymnasiums, clubhouses, athletic clubs, dance studios	NC	NC	C, 50	I	I
	Inpatient medical: hospitals, mental hospitals	NC	C, 45	NC	I	I
	Outpatient medical: healthcare centers, clinics	NC	C, 45	C, 45	I	I
	Penal institutions: prisons, reformatories	NC	C, 45	C, 45	I	I
	Public safety facilities: police, fire stations	NC	NC	C, 50	C, 50	I
Commercial, office and service uses:
	Major retail: regional shopping centers, "big box" retail	NC	NC	C, 50	I	I
	Local retail: community/neighborhood shopping centers, grocery stores	NC	NC	C, 50	I	I
	Eating/drinking establishments: restaurants, fast food dining, bars	NC	NC	C, 50	I	I
	Limited retail/wholesale: furniture, automobiles, heavy equipment, lumberyards, nurseries	NC	NC	C, 50	I	I
	Offices: professional services, doctors, finance, civic; radio, television and recording studios, office space associated with other listed uses	NC	NC	C, 50	I	I
	Personal and miscellaneous services: barbers, car washes, print shops	NC	NC	C, 50	I	I
	Vehicle fueling: gas stations, trucking and transportation terminals	NC	NC	NC	C, 50	C, 50
Industrial, manufacturing, and storage uses:
	Hazardous materials production: oil refineries, chemical plants	NC	NC	NC	NC	NC
	Heavy industrial	NC	NC	NC	NC	NC
	Light industrial, high intensity: food products preparation, electronic equipment	NC	NC	NC	C, 50	C, 50
	Light industrial, low intensity: machine shops, wood products, auto repair	NC	NC	NC	C, 50	C, 50
	Research and development	NC	NC	C, 50	C, 50	I
	Indoor storage: wholesale sales, warehouses, mini/other indoor storage, barns, greenhouses	NC	NC	NC	NC	NC
	Outdoor storage: public works yards, automobile dismantling	NC	NC	NC	NC	NC
	Mining and extraction	NC	NC	NC	NC	NC
Transportation, communication, and utilities:
	Airport terminals: airline, general aviation	NC	NC	NC	C, 50	I
	Rail and bus stations	NC	NC	NC	C, 50	I

Transportation routes: road and rail rights of way, bus stops	NC	NC	NC	NC	NC
Auto parking: surface lots, structures	NC	NC	NC	NC	NC
Communications facilities: emergency communications, broadcast and cell towers	NC	NC	NC	NC	NC
Power plants	NC	NC	NC	NC	NC
Electrical substations	NC	NC	NC	NC	NC
Wastewater facilities: treatment, disposal	NC	NC	NC	NC	NC
Solid waste disposal facilities: landfill, incineration	NC	NC	NC	NC	NC
Solid waste transfer facilities, recycle centers	NC	NC	NC	NC	NC

Notes:

Conditional Criteria:

Compatible at levels indicated, but noise disruption of natural quiet will occur.
Exercise caution with uses involving noise sensitive animals.
Exercise caution if clear audibility by users is essential.
Compatible at levels indicated, but noise disruption of outdoor activities will occur.
Only on existing residential parcels; no subdivisions are allowed.
Applies only to classrooms; offices, laboratory facilities, gymnasiums, outdoor athletic facilities, and other uses to be evaluated as indicated for those land use categories.

C. Single Event Noise Levels: Single event noise levels shall be considered when evaluating the compatibility of highly noise sensitive land uses such as residences, schools, libraries, and outdoor theaters. Susceptibility to speech interference and sleep disturbance are among the factors that make certain land uses noise sensitive. Single event noise levels are especially important in areas that are regularly overflown by aircraft, but that do not produce significant CNEL contours (helicopter overflight areas are a particular example). Flight patterns for Porterville Municipal Airport shall be considered in the review process. Acoustical studies or on site noise measurements may be required to assist in determining the compatibility of sensitive uses.

D. Maximum Acceptable Interior Noise Levels: Land uses for which interior activities may be easily disrupted by noise shall comply with the following maximum, aircraft related, interior noise level criteria:

CNEL forty (40) dB in any habitable room of single- or multi- family residences.
CNEL forty five (45) dB for: hotels, motels, and other lodging; hospitals and nursing homes; places of worship, meeting halls, theaters, and mortuaries; and schools, libraries, and museums.
CNEL fifty (50) dB in offices and office areas of industrial facilities.

E. Residential Interior Noise Level Reduction: New dwellings exposed to CNEL above sixty (60) dB shall incorporate the following noise reduction design measures unless alternative designs that achieve and maintain an interior noise level of CNEL forty (40) dB are incorporated and verified by a board certified acoustical engineer:

All facades must be constructed with substantial weight and insulation;
Sound rated windows providing noise reduction performance similar to that of the facade must be included for habitable rooms;
Sound rated doors or storm doors providing noise reduction performance similar to that of the facade must be included for all exterior entries;
Acoustic baffling of vents is required for chimneys, fans, and gable ends;
Installation of a mechanical ventilation system affording comfort under closed window conditions; and
Double stud construction, double doors, and heavy roofs with ceilings of two (2) layers of gypsum board on resilient channels. (Ord. 1801, 12-3-2013)