(A) The purpose of this section is to require that new or redeveloped buildings within the Noise Zones Area, Airport Overlay (AO-4) District, be constructed with materials and in such manner that aircraft noise is reduced by the structure to an interior level which has no adverse impact on the health, safety and general welfare of the residents.
(B) The AO-4 District designates the area that primarily includes standards for the attenuation of noise.
(C) Establishment of Noise Zones.
(1) Buildings, structures, or land shall be occupied or used only in conformity with all of the regulations set forth herein for the district in which they are located. The boundaries of the noise contour zones are shown on the map in § 151.078. There are four applicable noise zones:
(a) NZ 1: Area within the noise zone where the DNL is between 65 and 69 dB;
(b) NZ 2: Area within the noise zone where the DNL is between 70 and 74 dB;
(c) NZ 3: Area within the noise zone where the DNL is between 75 and 79 dB; and
(d) NZ 4: Area within the noise zone where the DNL is greater than 80 dB.
(2) Other industry-standard noise zones exist around the airfields. However, all land uses are considered compatible with noise levels below 65 dB. Noise Zone 4 is only located on federally controlled land.