The US EPA's National Nutrient Inventory: Critical Shifts in US Nutrient Pollution Sources from 1987 to 2017.

ABSTRACT: Efforts to constrain the negative environmental impacts of excess nitrogen (N) and phosphorus (P) are costly and challenging, due in part to inconsistent reporting of nutrient sources at temporal and spatial scales relevant for local decision making. To meet this challenge, the U.S. Environmental Protection Agency's National Nutrient Inventory provides estimates of major agricultural, urban, atmospheric, and natural nutrient fluxes for the contiguous United States at county and HUC12 scales annually from 1987 (from 1950 for agriculture) to 2017. Since the late 1980s, total N emissions and atmospheric N deposition have declined 22% and 15%, respectively, despite increased agricultural emissions. Over the same period, municipal wastewater N and P loads remained largely stable, despite popula

SUBMITTER: Brehob MM 

PROVIDER: S-EPMC12756919 | biostudies-literature | 2025 Dec

REPOSITORIES: biostudies-literature