Addressing Water Quality through Nutrient Management

This fact sheet by the Environmental and Energy Study Institute examines the impact of agricultural nutrient runoff—specifically nitrogen and phosphorus—on water quality in the United States, focusing on the Upper Midwest, the Great Lakes, and the Gulf of Mexico. It details the environmental consequences of eutrophication and hypoxia, the legal and regulatory landscape including the Clean Water Act's exemptions for irrigated agriculture, and the role of the USDA's Regional Conservation Partnership Program (RCPP) in funding voluntary conservation efforts to reduce pollution.

• Agricultural nonpoint source pollution is a primary driver of water contamination in the U.S., with nitrogen and phosphorus runoff causing eutrophication and hypoxic zones. In the Gulf of Mexico, a 2013 USGS report attributed 60 percent of nitrogen loads and 49 percent of phosphorous loads to agricultural nonpoint source pollution. Hypoxic zones, where oxygen levels fall below 2 milligrams per liter, can lead to mass animal die-offs; in 2015, the Gulf of Mexico's hypoxic zone was over 930 square miles larger than the five-year average, reaching a size three times larger than the Hypoxia Task Force's target of 1,991 square miles.
• Nutrient runoff has caused severe water quality crises in the Great Lakes region. In August 2014, a harmful algal bloom in Lake Erie left 400,000 people in Toledo, Ohio, without safe drinking water for three days. Research indicated that nonpoint nutrient sources from agriculture, which is the dominant land use on the western side of Lake Erie, accounted for 71 percent of the lake's nutrient loading.
• The Regional Conservation Partnership Program (RCPP), authorized by the 2014 Farm Bill, is a key USDA tool for reducing agricultural pollution through cross-sectoral partnerships. The USDA planned to invest up to $1.2 billion, with matching partner funds bringing the total to $2.4 billion for conservation through 2018. In February 2016, $600 million in USDA funding and $900 million in partner contributions were announced for RCPP projects. The program prioritizes nutrient management in critical areas like the Mississippi River Basin and the Great Lakes, promoting practices such as cover crops, no-till operations, and crop rotations.
• While the Clean Water Act does not regulate water leaving farmers' fields due to an exemption for irrigated agriculture, various states have implemented voluntary or mandatory measures. Iowa developed the science-based Iowa Nutrient Reduction Strategy. Ohio banned fertilizer application on saturated, frozen, or snow-covered soil in 24 counties within the Western Lake Erie Basin and established a national first by requiring a fertilizer applicator certification program. Michigan utilizes the voluntary Michigan Agriculture Environmental Assurance Program (MAEAP) for on-farm verification and risk assessment.

APA

Zayas, G. (2016). Addressing Water Quality through Nutrient Management. Environmental and Energy Study Institute. https://www.eesi.org/papers/view/fact-sheet-addressing-water-quality-through-nutrient-management

Chicago

Zayas, Gabriela. Addressing Water Quality through Nutrient Management. Environmental and Energy Study Institute, 2016. https://www.eesi.org/papers/view/fact-sheet-addressing-water-quality-through-nutrient-management.

Wikipedia

{{cite report |last1=Zayas |first1=Gabriela |title=Addressing Water Quality through Nutrient Management |publisher=Environmental and Energy Study Institute |date=1 December 2016 |url=https://www.eesi.org/papers/view/fact-sheet-addressing-water-quality-through-nutrient-management |access-date=17 August 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{zayas2016addressing, author = {Zayas, Gabriela}, title = {{Addressing Water Quality through Nutrient Management}}, institution = {Environmental and Energy Study Institute}, year = {2016}, month = dec, url = {https://www.eesi.org/papers/view/fact-sheet-addressing-water-quality-through-nutrient-management}, urldate = {2026-08-17}, note = {Indexed by Climate Insights Directory} }