What are major inputs of nitrogen and phosphorus from specific locations referred to as?

The major inputs of nitrogen and phosphorus from specific locations are referred to as point sources. Point sources are identifiable, localized sources of pollution that discharge contaminants directly into a body of water, such as a sewage treatment plant, industrial discharge, or a wastewater treatment facility. These sources are characterized by their specific points of origin, making it easier to regulate and manage their impact on water quality.

In contrast, other terms like diffuse sources and non-point sources refer to pollution that comes from a broad area rather than a single identifiable location. For instance, non-point sources could involve runoff from agricultural fields, urban areas, or other widespread surfaces that contribute nutrients to waterways in a more dispersed manner. Surface sources, while relating to sources of nutrients, do not capture the concept of specific locations as clearly as point sources do. Therefore, the definition and characteristics of point sources make it the correct choice in this context.