Morrisville UDO - June 2017 version

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Article 3: Zoning Districts
Section 3.8. Overlay Districts
3.8.2. Airport Overlay (AO) Districts
June 23, 2017 Morrisville, NC
Page 3-62 Unified Development Ordinance
C. Modifications of Otherwise Applicable Standards
Uses Prohibited in Airport Overlay-A (AO-A) District
Irrespective of the use standards applicable in the underlying base, conditional, or planned
development district, or in any other applicable overlay district, certain uses shall be prohibited in
the Airport Overlay-A (AO-A) District, as indicated in the use tables in
Underground Storage of Hazardous Chemicals and Substances
In the Airport Overlay-A District or Airport Overlay-B District, permanent or long-term storage of
significant quantities of highly explosive, flammable, toxic, corrosive, or otherwise hazardous
liquids, gases, chemicals, or other hazardous substances shall be located underground to reduce
the hazardous consequences from an airplane crash.
Structure Height
The height of any structure in the Airport Overlay-A District or Airport Overlay-B District shall not
exceed that which constitutes an obstruction to air navigation, navigational aids, or navigational
facilities under standards of the Federal Aviation Administration (FAA) in 14 CFR Part 77, Subpart
C, as applied to the area around Raleigh-Durham International Airport, unless the FAA determines
no substantial obstruction exists in accordance with 14 CFR Part 77, Subpart D. Documentation of
compliance with this requirement may be required for any structure or structural alteration that
extends more than 50 feet above ground level.
Outdoor Lighting
a. Outdoor lighting in the Airport Overlay-A District or Airport Overlay-B District shall be shielded
to minimize direct skyward glare from the light source and otherwise located and designed to
avoid producing light emissions—whether direct or indirect (reflective) of such intensity and
directed in such directions as to impair pilot visibility or otherwise interfere with the safe
operation of overhead aircraft.
b. Lighting of towers, tall buildings, and other potential obstructions to air navigation shall include
warning lighting that complies with FAA standards in Advisory Circular 70/7460-1 (Obstruction
Marking and Lighting).
Electronic Interference
No use, development, or activity in the Airport Overlay-A District or Airport Overlay-B District shall
produce electronic emissions that interfere with navigation signals or radio communications between
aircraft and landing control facilities or with aircraft navigational or communication equipment.
Sound Mitigation
a. Airport Overlay-A
New construction, or substantial improvement, of buildings within the Airport Overlay-A District
shall be designed to limit interior noise from aircraft to an average day/night sound level
(DNL) of 45 dB in the following use categories if permitted in Table
(1) Group Living Uses (e.g. dormitories);
(2) Community and Government Service Uses (e.g. clubs or lodges, college or universities,
public park or recreation facilities, business or vocational schools, or sports academies);
and
(3) Health Care Uses (e.g. hospitals, nursing homes).