35 Ill. Adm. Code 901.106
Prominent Discrete Tones
Section 901
Section 901.106Â Prominent
Discrete Tones
a)Â Â Â Â Â Â Â Â A person must not cause or allow the emission of any prominent
discrete tone from any property-line noise source located on any Class A, B or
C land to any receiving Class A, B or C land, when measured at any point within
the receiving land. One-third octave band sound pressure levels must be measured
at least 25 feet from the property-line noise source.
b)Â Â Â Â Â Â Â Â Subsection (a) does not apply to prominent discrete tones
having a one-third octave band sound pressure level 10 or more dB below the
allowable octave band sound pressure level specified in Sections 901.102
through 901.104 for the octave band that contains the one-third octave band.Â
In the application of this subsection, the applicable numeric standard for
sound emitted from any existing property-line noise source to receiving Class A
land, for both daytime and nighttime operations, is found in Section 901.102(a).