Glossary N

The Environmental Glossary. Letter N +++ 'Nutrient', 'Nitrogen fixation', 'Natural gas'

Nonparametric Tests are all studies involving ranked data, i.e., data that can be put in order and used when there is no assumption that the population has a normal distribution or when the population is known to have low and high values and valuable in detecting population differences when certain assumptions are not satisfied.

Nonpoint source are the large or dispersed land areas such as crop fields, streets, and lawns that Discharge pollutants into the environment over a large area. Compare point source.
A Nonpoint Source Pollution is "Diffuse” pollution, generated from large areas with no particular point of pollutant origin, but rather from many individual places.
A Nonrenewable resource is a natural resource from the Earth that exists in limited supply, like oil or coal. Once this supply is used up, the resource is gone forever.

A Nonroad mobile sources is a Mobile sources not found on roads and highways (e.g., airplanes, trains, lawn mowers, construction vehicles, farm machinery).

A Nonwastewater (NWW) is Wastes that do not meet the Criteria for wastewaters defined below.

The Normal Distribution (statistical) is a frequency of data occurrence where most of the data points are located near the mean; seen statistically as a symmetrical bell-shaped curve.

A Nose Cone is Rounded deflectors attached to the front of a straight truck or box van that extends slightly over the cab of the truck. These devices may also be known as aerodynamic
A NPDES is National Pollutant Discharge Elimination System.