§ 11-5-5. Same—decibel provisions.

(a)

Classification of use areas: residential, commercial, and industrial.

(1)

Except as otherwise provided by this chapter, on or after July 1, 1977, it shall be unlawful to project a sound or noise beyond the boundaries of the property from which such noise emanates which exceeds any of the limiting noise spectra set forth in Table III of this subsection which are applicable to that property. For the purposes of this section, the limiting noise spectra set forth in Table III of this subsection for industrial use areas shall be deemed to be the limiting noise spectra applicable to any property which is not located in a residential, commercial or industrial use area.

(2)

The measurement of sound or noise pursuant to this subsection shall be as follows:

a.

The measurement of sound or noise shall be made with sound level meters type 1 or type 2 and meeting the standards prescribed by the American National Standards Institute, Inc., New York, New York. The instrument shall be maintained in calibration and good working order. Octave band corrections may be employed in meeting the response specification. A calibration shall be made of the system before and after the noise measurements. Measurements recorded shall be taken so as to provide a proper representation of the noise source. The microphone during measurement shall be positioned so as not to create any unnatural enhancement or diminution of the measured noise. A windscreen for the microphone shall be used when required. Other than for instantaneous sound levels or for stated lengths of time, such as eight-hour or 24-hour averages, the following procedure will be used. With a continuous noise source in operation, a minimum of nine sound level readings will be taken at least 20 seconds apart excluding any readings taken it there is significant noise from extraneous sources. If the noise source is periodic or cyclical in nature, nine readings at least 20 seconds apart will be made only during those parts of the cycle when the source is operating, No readings will be made during the parts of the cycle when the source is not operating. The median of the valid readings will be used as the average sound level.

b.

The slow meter response of the sound level meter shall be used to determine that the maximum permissible dB(A) readings or the octave band levels set forth in Table III below have not been exceeded.

c.

Unless otherwise specified the measurement shall be made at the boundary of the property on which such noise is generated, or perceived, as appropriate not less than three and one-half (3½) feet above ground.

d.

Compliance with the noise limits is to be maintained at any elevation at the boundary.

(3)

The limits hereinabove referred to shall be in accordance with the following table:

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TABLE III
MAXIMUM PERMISSIBLE SOUND LEVELS
		Octave Band
Use Areas	Maximum dB(A)	Center Frequency Hertz-(HZ)	Levels dB
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Residential	55	31.5	70
		63	69
		125	64
		250	59
		500	53
		1,000	47
		2,000	42
		4,000	38
		8,000	35
Commercial	60	31.5	75
		63	74
		125	69
		250	64
		500	58
		1,000	52
		2,000	47
		4,000	43
		8,000	40
Industrial	70	31.5	85
		63	84
		125	79
		250	74
		500	68
		1,000	62
		2,000	57
		4,000	53
		8,000	50
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(4)

The maximum permissible sound levels established in Table III for application to the boundaries of a property shall not applied to construction sites. Construction site noise shall be regulated by section 11-5-4(b)(10) and 11-5-4(b)(15) and other appropriate sections of this chapter.

(5)

a. Days which shall have the same restrictions as Sundays are New Year's Day (the first day of January), Memorial Day (the last Monday in May). Independence Day (July 4), Labor Day (the first Monday in September). Thanksgiving Day (the fourth Thursday in November), and Christmas Day (December 25).

b.

The provisions of section 11-5-5(a)(5)a. of this chapter shall not be applicable to any noise which is emitted without interruption for 24 hours every day for at least seven consecutive days, when the noise varies in intensity by less than three decibels in a 24-hour period; provided, that a permit for the emission of such noise has been issued by the city manager. Any permit shall be issued pursuant to section 11-5-7 of this chapter. Any permit issued by the city manager pursuant to this section, shall be valid until such time as the city manager, after giving notice in writing, to the applicants for the permit at least 30 days in advance, shall modify or revoke the permit.

(b)

Power equipment and power lawn and garden equipment. It shall be unlawful to operate in the city any equipment which creates a noise or sound that exceeds the noise level limits set out in Table IV below. This equipment shall not be used during hours prohibited by either section 11-5-4(b)(15) or section 11-5-4(b)(16), as applicable.

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TABLE IV
LIMITING NOISE LEVELS FOR POWER LAWN OR GARDEN EQUIPMENT AND POWER EQUIPMENT
_____
Maximum Permissible Noise Level	75 dB(A)
Location of Measurements	Property Line of Noise Source
Measurement Procedure	As stated in sec. 11-5-5(a)(2)a.

 

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(c)

Motorized vehicles and equipment. It shall be unlawful to operate a motor vehicle within the city which creates a noise or sound which exceeds the noise level limits set out in Table V below. The measurement of sound or noise shall be made with standards prescribed by the American National Standards Institute, Inc., New York, New York. A calibration shall be made of the sound level meter before and after any noise measurement. The slow meter response of the sound level meter shall be used. Measurement shall be approximately three and one-half feet above ground and a windscreen for the microphone shall be used when required.

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TABLE V
LIMITING NOISE LEVELS FOR MOTOR VEHICLES
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(a)

Passenger cars: (Reserved for future use)

(b)

Motorcycles, and motor-bicycles: (Reserved for future use)

(c)

Motorized construction device:

90 dB(A) measured at 50 feet … Maximum allowable limit for equipment purchased prior to July 1, 1977.

85 dB(A) measured at 50 feet … Maximum allowable limit for equipment purchased after July 1, 1977.

(d)

Refuse collection vehicle:

Arithmetic average of readings on four sides at a distance of seven meters at maximum engine speed for compacting with vehicle stationary shall not exceed 79 dB(A) after October 1, 1980, and 76 dB(A) after July 1, 1982.

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(d)

Places of entertainment. Noise levels and conditions of operation shall conform to title 9, chapter 7 of the city code.

(e)

Noises—rail rapid transit systems.

(1)

It shall be unlawful to operate or permit to be operated a rail rapid transit system including but not limited to its rolling stock, track and track beds, passenger stations, tunnels, elevated structures, yards, depots and garages in violation of any of the provisions of this subsection.

(2)

It shall be unlawful to operate or permit to be operated in the city a rail rapid transit system train which emits maximum transient noise levels in excess of those set forth in Table VI, below. The measurement of sound or noise shall be made with sound level meters, type 1 or type 2 meeting the standards prescribed by the American National Standards Institute, Inc., New York, New York. A calibration shall be made of the sound level meter before and after any noise measurement. The slow meter response of the sound level meter shall be used. Measurement shall be not less than three and one-half feet above ground and a windscreen for the microphone shall be used when required. For purposes of this subsection, the limiting noise level set forth in part(c) of Table VI below shall be deemed to be the noise level applicable to transient noise which is emitted in an area that is not a residential, commercial or industrial use area.

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TABLE VI
LIMITING NOISE LEVELS*
(Above ground trains)
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(a) Residential	75 dB(A)
(b) Commercial	80 dB(A)
(c) Industrial	90 dB(A)

 

*At a point 100 feet from track center line, or the nearest nonindustrial property line, whichever is the greater distance from the track center line.

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