Morrisville Unified Development Ordinance - June 2017

Article 3: Zoning Districts Section 3.8. Overlay Districts 3.8.2. Airport Overlay (AO) Districts

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 Article 4: Use Standards. 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 4.2.4, Principal Use 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).

June 23, 2017 Morrisville, NC Page 3-64 Unified Development Ordinance