4-8-8-1: NOISE:
   A.   Compliance Required: Any use established in the M-1 Restricted Manufacturing District after the effective date hereof shall be so operated as to comply with the performance standards governing noise set forth hereinafter for the District. No use lawfully established on the effective date hereof shall be so altered or modified as to conflict with, or further conflict with, the performance standards governing noise established hereinafter.
   B.   Measurement of Sound: Sound levels shall be measured with a sound level meter and associated octave band filter manufactured according to standards prescribed by the American Standards Association. Measurements shall be made using the flat network of the sound level meter. Impulsive type noises shall be subject to the performance standards hereinafter prescribed, provided that such noises shall be capable of being accurately measured with such equipment. Noises capable of being so measured, for the purpose of this Title, shall be those noises which cause rapid fluctuations of the needle of the sound level meter with a variation of no more than plus or minus two (2) decibels. Noises incapable of being so measured, such as those of an irregular and intermittent nature, shall be controlled so as not to become a nuisance to adjacent uses.
   C.   Maximum Noise Levels: In the M-1 Restricted Manufacturing District, at no point on the boundary of a residence district or a business district shall the sound pressure level of any operation or plant (other then background noises produced by sources not under control of this Title, such as the operation of motor vehicles or other transportation facilities) exceed the decibel limits in the octave bands designated below.
Octave Band
Frequency
cycles per second)
Maximum Permitted
Sound Level
(in decibels)
Along Residence
District Boundaries
Octave Band
Frequency
cycles per second)
Maximum Permitted
Sound Level
(in decibels)
Along Residence
District Boundaries
0 to 75
72
75 to 150
67
150 to 300
59
300 to 600
52
600 to 1,200
46
1,200 to 2,400
40
2,400 to 4,800
34
Above 4,800
32
 
Octave Band
Frequency
(cycles per second)
Maximum Permitted
Sound Level
(in decibels) Along Business
District Boundaries
Octave Band
Frequency
(cycles per second)
Maximum Permitted
Sound Level
(in decibels) Along Business
District Boundaries
0 to 75
78
75 to 150
74
150 to 300
66
300 to 600
59
600 to 1,200
53
1,200 to 2,400
47
2,400 to 4,800
41
Above 4,800
39