> For the complete documentation index, see [llms.txt](https://swatplus.gitbook.io/io-docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://swatplus.gitbook.io/io-docs/introduction-1/aquifers/aquifer.aqu/no3_n.md).

# no3\_n

Nitrate levels in the aquifer are modeled, allowing for variation in nitrate concentration of groundwater flowing to the receiving spatial object(s). Accordingly, groundwater nitrate loads vary with nitrate concentration and groundwater flow.