Duluth UDC (unnumbered, p.402: Definitions — N)

National Geodetic Vertical Datum (NGVD). As corrected in 1929, is a vertical control used as a reference for establishing varying elevations within the floodplain. 401 | P a g e Article Fourteen. Interpretation and Definitions National Pollutant Discharge Elimination System (NPDES) Stormwater Discharge Permit. A permit issued by the state EPD under authority delegated pursuant to 33 USC § 1342(b) that authorizes the discharge of pollutants to waters of the United States, whether the permit is applicable on an individual, group, or general area-wide basis. Native tree. A tree species that naturally occurs within the City of Duluth or the Piedmont area of Georgia in which the City of Duluth is located. See the City of Duluth Tree Species List for information on which species are considered native. Natural Buffer. See under “Buffer.” Natural Ground Surface. The ground surface in its original state before any grading, excavation, or filling. Nephelometric Turbidity Units (NTU). Numerical units of measure based upon photometric analytical techniques for measuring the light scattered by finely divided particles of a substance in suspension. This technique is used to estimate the extent of turbidity in water in which colloidally dispersed or suspended particles are present. New Construction. Any structure (see definition in this Section) for which the "start of construction" commenced after December 17, 1975 and includes any subsequent improvements to the structure. New Development. A land development activity on a previously undeveloped site. New Manufactured Home Park or Subdivision. A manufactured home park or subdivision for which the construction of facilities for servicing the lots on which the manufactured homes are to be affixed (including at a minimum, the installation of utilities, the construction of streets, and either final site grading or the pouring of concrete pads) is completed on or after December 17, 1975. NOI. A Notice of Intent form provided by EPD for coverage under the State General Permit. Non-Development Activity. Any alteration of the natural environment that does not require development or site plan approval, but that would include the proposed removal or destruction of any trees. Any removal of trees that constitutes Development Activity as that term is herein defined shall not constitute Non-Development Activity. Nonpoint Source Pollution. A form of water pollution that does not originate from a discrete point such as a sewage treatment plant or industrial discharge, but involves the transport of pollutants such as sediment, fertilizers, pesticides, heavy metals, oil, grease, bacteria, organic materials and other contaminants from land to surface water and groundwater via mechanisms such as precipitation, stormwater runoff, and leaching. Nonpoint source pollution is a by-product of land use practices such as agricultural, silvicultural, mining, construction, subsurface disposal and urban runoff sources. Non-Stormwater. Any surface flow, runoff, drainage, or discharge that is not composed entirely of stormwater and which may include pollutants, but that excludes: 1. Water from those sources described in this article; and/or, 2. Any discharge permitted under NPDES permit or order issued to the discharger and administered under the authority of the state and the federal Environmental Protection Agency, provided that the discharger is in full compliance with all requirements of the permit, waiver, or order and other applicable laws and regulations, and provided that written approval has been granted for any discharge to the city separate storm sewer system. Nonresidential Use. See “Use, nonresidential.” Nonstructural Stormwater Management Practice or Nonstructural Practice. Any natural or planted vegetation or other nonstructural component of the stormwater management plan that provides for or enhances stormwater quantity and/or quality control or other stormwater management benefits, and includes, but is not limited to, riparian buffers, open and greenspace areas, overland flow filtration areas, natural depressions, and vegetated channels. 402 | P a g e Article Fourteen. Interpretation and Definitions North American Vertical Datum (NAVD) of 1988. A vertical control used as a reference for establishing varying elevations within the floodplain. NOT. A Notice of Termination form provided by EPD to terminate coverage under the State General Permit.