Erosion and Sediment Pollution Control Program Manual.pdf

NOI -----Notice of Intent
Nominal Size -----The order size for a material — the actual size typically varies from the nominal size.
Nomograph -----A graph that can be used to determine an unknown value from one or more known
values.
Noncohesive Soil -----Soil having particles that have no natural resistance to being pulled apart at their
point of contact, such as silt, sand, and gravel.
Nondischarge Alternative -----Environmentally-sound and cost-effective BMPs that individually or
collectively eliminate the net change in stormwater volume, rate and quality for storm events up
to and including the 2-year/24-hour storm when compared to the stormwater rate, volume and
quality prior to the earth disturbance activities to maintain and protect the existing quality of the
receiving surface waters of this Commonwealth.
Nonpathogenic -----Not capable of causing disease.
Non-Point Source Pollution -----Pollution originating from diffuse sources.
Nonstructural BMP -----A method of protecting receiving surface water quality that does not require
construction.
Normal Depth -----The depth of uniform flow.
Normal Flow Depth -----The depth of flow in an open conduit during uniform flow for a given set of
conditions.
Normal Pool -----Design water surface elevation in a basin, trap, pond, or dam.
Normal Pool Elevation -----1. For bodies of water that have no structural measures to regulate height
of water, the height of water at ordinary stages of low water unaffected by drought. 2. For
structurally regulated bodies of water, the elevation of the spillway, outlet control, or dam crest
which maintains the body of water at a specified height. 3. The term does not apply to
wetlands.
Normal Water Level -----The average summer water level. The free surface associated with flow in
natural streams.
Normally Consolidated Soil -----Soil that has never been consolidated by a greater stress than
presently existing.
North American Vertical Datum Plane -----The elevation datum currently used by FEMA for
determination of flood elevations.
NOT -----Notice of Termination
Notch -----The opening in a dam or spillway for the passage of water.
Notice of Intent ----- A request, on a form provided by the Department, for coverage under a General
NPDES Permit for Stormwater Discharges Associated with Construction Activities or an E&S
Permit.
Notice of Termination -----A request, on a form provided by the Department, to terminate coverage
under a General or Individual NPDES Permit for Stormwater Discharges Associated with
Construction Activities or other permits under Chapter 102.
Nourishment -----The process of replenishing a beach, either naturally through accretion due to the
longshore transport, or artificially through the deposition of dredged materials.
NOV -----Notice of violation. An official letter from a Conservation district or DEP to an earthmover
notifying him/her that one or more significant violations exist at a specific project site.
Noxious Plant -----A harmful plant species.
Noxious Weed -----A plant species having one or more of the following attributes: aggressive and
difficult to manage, poisonous, toxic, parasitic, a carrier or host of serious insect or disease and
being native or new to or not common to the U.S. or parts thereof.
NPDES -----National Pollutant Discharge Elimination System - The national system for the issuance of
permits under s33 U.S.C.A. § 1342 including a state or interstate program that has been
approved in whole or in part by the EPA, including the regulations codified in Chapter 92a
(relating to National Pollution Discharge Elimination System Permitting, Monitoring and
Compliance), and as specified in Chapter 102 ( relating to Erosion and Sediment Control).
NPDES Permit for Stormwater Discharges Associated With Construction Activities -----A permit
required for the discharge or potential discharge of stormwater into waters of this
Commonwealth from construction activities, including clearing and grubbing, grading and
excavation activities involving 1 acre (0.4 hectares) or more of earth disturbance activity or an
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