Nitrates leached into groundwater may be associated with the following: (1) methemoglobinemia (blue baby) in humans and other mammals; (2)cardiovascular collapse and shock in horses; (3) possibility of cancer (EPA); and (4) eutrophication of water bodies (IFIA) when nitrate contaminated groundwater reaches surface water through wells or springs. Nitrate leaching is not only a possible source of environmental damage but also the loss of an input before it is used in production.
Miller, Gilbert D. and Andersen, Jay C., "Managing to Reduce Nitrate Leaching: What is in it for the Farmer?" (1999). All Archived Publications. Paper 426.