Animal Ag Water Pollution Sources
What are the main sources of nutrient pollution from animal ag? The primary sources of nitrogen and phosphorus are: Concentrated amounts of manure on factory farms. Excess use of chemical fertilizers on feed crops. Crop fixation of nitrogen by soybeans and alfalfa/hay. For estimated respective shares of pollution see, spreadsheet for animal ag’s contribution https://docs.google.com/spreadsheets/d/16vc25ZTFcsp-IBDewc6zXcN8aAAbTHRJa92lFaQ0wpw/edit?gid=0#gid=0 For a […]
Animal Ag GHG Emissions
What share of total U.S. GHG emissions comes from agriculture? The EPA reports that in 2023, agriculture was responsible for 10.5% of total U.S. anthropogenic greenhouse gas emissions.[1-3] This figure includes on-farm energy use.[4] EPA (2025) Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2023, EPA 430-R-25-003. p. ES-23. (Hereafter: “EPA (2025) Inventory GHG 2023”)[“Activities […]
Animal Ag’s Contributions to Water Pollution
What is the key takeaway regarding animal ag’s contributions to U.S. water pollution? Industrial animal agriculture is the primary contributor to the failing grades of U.S. waterways, responsible for about 50% of nutrient pollution – the leading cause of U.S. water pollution.[1] As noted in previous pages of this section: U.S. waterways have received failing grades […]
Agriculture’s Contributions to Water Pollution
Is agriculture the main source of U.S. water pollution? Yes. As noted on this page, U.S. agriculture is the primary source of nutrient pollution. As noted on previous pages, nutrient pollution is the primary driver of the pollution of U.S. waterways.[1,2] Federal agencies have occasionally stated that agriculture is the primary source of water pollution.[3] […]
Lakes, Rivers & Streams Pollution
How does the EPA evaluate the health of waterways? The EPA generates reports approximately every five years, separately assessing each of 4 categories of waterways. Known as the National Aquatic Resource Surveys (NARS), they cover: Lakes – published 2024 covering 2022.[1] Wetlands – published 2024 covering 2021.[2] Rivers & Streams – published 2023 covering 2018-2019.[3] Coastal Zones including […]
Agricultural GHG Emissions
What share of total U.S. GHG emissions comes from agriculture? There are 3 possible answers according to EPA data: 9.6% – This is for direct on-the-farm (and factory farm) emissions and does not include on-the-farm fossil fuel and electric use.[1] 10.5% – This is for direct on-the-farm emissions plus on-the-farm fossil fuel and electric use.[2] […]
Nutrient Pollution of Waterways
What is nutrient pollution? Put simply, nutrient pollution is “too much nitrogen and phosphorus in the air and water.”[1] Nutrient pollution negatively impacts water quality, air quality, greenhouse gas balances, ecosystems and biodiversity, and soil quality.[2] Since water pollution is the primary impact, nutrient pollution is sometimes specifically defined as “excess amounts of nitrogen and […]
U.S. Share of GHG Emissions
How does climate change differ from other negative externalities of animal ag? There are two fundamental differences: Climate change impacts are global. Other negative externalities of animal ag are either mostly or exclusively regional or national. One ton of CO2 emissions from the U.S. is evenly mixed throughout the earth’s atmosphere in about a year.[1,2] […]
Animal Ag Drivers of Zoonoses
What are the different routes by which animal ag contributes to zoonotic diseases? Animal ag heightens zoonotic disease risk through both direct and indirect routes. Direct exposure is at the factory farm level where the farmed animals are the original hosts, amplifiers, or transmitters of pathogens. Transmission of pathogens to humans can be via direct […]
Water Pollution and Animal Ag Overview
What is animal ag’s role in water pollution? Industrialized animal agriculture is the primary driver of the pollution of U.S. waterways.[1] The key points, as detailed in the following pages: Nutrient pollution (excess nitrogen and phosphorus in the environment) is the primary cause of pollution in U.S. waterways. Nutrient pollution causes eutrophication which leads to biological […]