No use established in any district after the effective date of this chapter shall be so operated as to exceed the performance standards established hereinafter. Any use already established on the effective date of this chapter shall be permitted to be altered, enlarged, expanded or modified provided that new sources of noise, vibration, smoke and particulate matter, toxic matter, odorous matter and glare shall conform to the performance standards established herein for the district in which such use is located.
(A) Noise limitations.
(1) (a) 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.
(b) 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.
(c) Noises capable of being so measured, for the purpose of this chapter, 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 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.
(2) No industrial activity shall be responsible for the transmission of noise across any residential or business zoning district boundary line in excess of the levels established below:
Preferred Center Frequency | 8:01 a.m. to 10:00 p.m. | Sound Level in Decibels (Re .0002 Microbar) 10:01 p.m. to 8:00 a.m. |
31.5 | 79 | 73 |
1,000 | 50 | 44 |
2,000 | 46 | 40 |
4,000 | 43 | 37 |
8,000 | 40 | 34 |
(B) Vibration limitations.
(1) Earthborne vibrations from any industrial operation, equipment, or process shall not constitute a nuisance nor exceed the displacement limits set forth herein. Vibrations shall be expressed as displacement in inches and shall be measured with a three-component measuring system.
(2) (a) No industrial activity shall be responsible for the transmission of earthborne vibrations across any residence or business zoning district boundary line in excess of the displacement limits established through use of the following formula:
D = .001 K
F
F
where:
D = The maximum allowable displacement in inches;
F = The vibration frequency in cycles per second; and
K = The value set forth in the following table:
Type of Vibration | K Value |
Constant | 3 |
Impulsive | 6 |
Impact | 15 |
(b) For the purpose of this division (B)(2), CONSTANT VIBRATIONS are those which are continuous or which occur in discrete pulses more frequent than one per second; IMPULSIVE VIBRATIONS
are those which occur in discrete pulses less frequent than one per second; and IMPACT VIBRATIONS are those which occur in discrete pulses separated by an interval of at least one minute.
(C) Glare limitations. In any industrial district, any operation or activity producing intense glare shall be so conducted that direct and indirect illumination from the source of light shall not cause illumination in excess of one-half of one footcandle when measured at any residential district boundary line. Flickering or intense sources of light shall be so controlled as not to cause a nuisance across any lot lines.
(D) Heat limitations. No direct or reflected heat shall be detectable from any lot line.
(E) Radioactivity. No operation shall be permitted which causes radioactivity in violation of federal or state regulations.
(Prior Code, § 166.072) (Ord. 2151, passed 6-28-1971)