Background:
Nitrates in drinking water sources have become a chronic problem especially in areas of intensive corporate agriculture–like the U.S. Midwest. The U.S. Environmental Protection Agency has not updated standards for nitrates in water for decades. Research indicates that health problems can be caused by levels far below the current U.S. Federal maximum.
“Nitrate (NO 3−) is a compound commonly found in fertilizers, animal manures, and wastewater sewage. Nitrate originating from agricultural activities, industrial discharges, and wastewater treatment processes can contaminate drinking water sources such as groundwater and surface water bodies … High levels of nitrate have been found in surface and groundwater drinking water sources across the United States, notably in regions characterized by intensive farming and animal production. As the primary producer of corn and swine in the U.S., Iowa faces challenges in managing nutrient levels in the environment.”
From: Mantey, E. P., Liu, L., & Rehmann, C. R. (2025). Disparities in potential nitrate exposures within Iowa public water systems. Environmental Science. Water Research & Technology, 11(4), 959-971. [PDF] [Cited by]
“… The pervasive overuse of synthetic fertilizers in large-scale industrial agriculture is straining the systems that keep our water safe. Fertilizer provides nutrients like nitrogen and phosphorus that crops need to grow and thrive. But today’s agricultural system, shaped by a powerful fertilizer industry and other corporate interests, pressures farmers to plant more acres and apply far more fertilizer than crops can use. In fact, only about half of the fertilizer applied to fields is actually used by plants. The rest can build up in soil, pollute the air, leach into groundwater, or wash into streams where it becomes “nutrient pollution.”
From: Woods, Stacy. (2025). From Fields to Faucets: Fertilizer Overuse Threatens Drinking Water and Health. Union of Concerned Scientists.
**updated July 2026**
More sources (Health):
*Sajid, A., & Semprini, J. (2026). Nitrate and Brain/CNS Cancer Diagnoses in the First Year of Life. Pediatric Blood & Cancer, 73(2), e70054.
[Journal page] [Cited by] [More information]
*Brender, J. D., & Weyer, P. J. (2016). Agricultural Compounds in Water and Birth Defects. Current Environmental Health Reports, 3(2), 144-152.
[Journal page] [Cited by] [More information]
*Cisneros, R., Amiri, M., & Gharibi, H. (2025). The association between increases in nitrate in drinking water and colorectal cancer incidence rates in California, USA. Cancer Causes & Control, 36(10), 1041-1057.
[Journal page] [PDF] [Cited by] [More information]
More sources (Agriculture):
*Hatfield, J. L., McMullen, L. D., & Jones, C. S. (2009). Nitrate-nitrogen patterns in the Raccoon River Basin related to agricultural practices. Journal of Soil and Water Conservation, 64, 190-199.
[Journal page] [PDF] [Cited by] [More information]
*Hall, A. L. (2024). ‘Cropaganda’: Mythology of Corn Belt agriculture. Journal of Rural Studies, 108, 103260.
[Journal page] [PDF] [Cited by] [More information]