Analysis: Spring Floods Exacerbate Pollution from Factory Farms Washing into Gulf of Mexico

Following the unprecedented climate-fueled flooding sweeping the Midwest this spring, Mighty Earth wanted to calculate approximately how much pollution is washing off America’s largest industrial factory farms into American waterways. Industrial meat production is the largest source of water pollution in the United States, yet this industry and its impacts are often left out of discussions around climate change. With the climate crises worsening and the Trump administration working to further roll back environmental regulations on industry, it is critical that the American public understand the sources and vast amounts of pollution washing into our waterways in order to hold specific companies and policymakers responsible for curbing uncontrolled industrial runoff.

The map below shows the locations of company facilities and the average per facility water pollutant data reported to EPA’s TRI database within the most recent 5-year period from 2012-2017. To view each company separately, click the cog icon in the legend to turn on specific company data layers. When clicking on a facility location, scroll down the pop up box to see the pollution calculations.

View the larger map

To assess how much pollution is being generated annually by the facilities of America’s largest meat companies, Mighty Earth analyzed water pollutant data reported by companies to the EPA’s Toxic Release Inventory (TRI) database and annual slaughter data reported in company or industry reports to evaluate total manure waste generated by each company. We mapped this data onto NOAA’s 2019 spring flooding outlook to identify which facilities were located in flood prone areas, and how much pollution those facilities were discharging onto the surrounding landscape. Full methodology and findings are below. We found that:

  • JBS came in as the top polluter, generating approximately 80 million tons of sewage.
  • In total, the top meat companies discharged nearly 220 million tons of manure and facility waste using practices that directly threaten nearby waterways with contamination, by either discharging pollutants directly into waterways, spreading pollutants onto the surrounding landscape, or storing pollutants in earthen impoundments that are highly prone to flooding and overflowing. This is approximately 500 times more sewage waste than is generated by New York City each year, yet unlike human waste, this waste from the meat industry is left untreated when it washes into waterways.
  • Facilities located in the Mississippi Watershed- which flows into the Gulf of Mexico- discharged an estimated 16 million lbs of sewage directly from facilities and 128 million tons of manure from supplying livestock and poultry production facilities.
  • Cargill had the most facilities concentrated in regions classified as by NOAA as ‘high risk’ for flooding in the spring of 2019, while Tyson had the highest exposure overall to flood risk areas.

The facilities of these corporate factory farms produce more sewage waste than some major U.S. cities, and this waste contains a variety of toxins and pathogens dangerous to human health including manure, nitrates, hydrogen sulfide, lead, E. coli, antibiotic resistant bacteria, growth hormones, and more.  Unlike human waste however, sewage from factory farms is not required to be treated before it is released into the surrounding environment. Common methods of disposing of sewage from factory farms are to spread the waste on surrounding crop fields, store it in massive open earthen pits prone to overflow or leaking, or discharge it directly into nearby waterways. Precipitation events like rain or snow then wash this waste downstream, contaminating drinking water across the Midwest with harmful toxins and creating dead zones fueled by toxic algae blooms in major watersheds like the Gulf of Mexico each summer.

While uncontrolled pollution from the meat industry has been a long-standing threat to our waterways, catastrophic floods exacerbated by climate change and the destruction of natural landscape buffers are increasingly turning America’s agricultural regions into open sewers filled in part by the meat industry’s waste. Last fall, Hurricane Florence devastated North Carolina as manure lagoons filled with hog waste overflowed across the landscape. This spring, unprecedented flooding swept the Midwest- the heart of the meat industry’s supply chain. As a result, NOAA has already issued predictions that the annual dead zone in the Gulf of Mexico, caused largely by the meat industry’s run-off pollution washing down the Mississippi River, is going to be larger than the annual average. The bulk of the meat industry’s pollution comes from the vast quantities of feed required to raise livestock and poultry, which was the focus of Mighty Earth’s Mystery Meat II report.

Costco's poultry plant in Fremont, Ohio impacted by flooding

The meat industry is highly consolidated, with a small handful of companies controlling between 60-90% of poultry, pork, and beef markets. These companies are responsible for the bulk of the industry’s impacts, yet can drive massive improvements at scale by changing farming practices in their supply chains. Recognizing that climate change is worsening while demand for meat is rising, Mighty Earth is leading a global campaign calling on the world’s largest food companies to require more sustainable farming practices that reduce the environmental devastation from industrial meat production.  You can see more about our work here.

Full Methodology


To calculate the amount of pollution generated by the facilities of America’s largest meat companies, we used company reported water pollutant data to the EPA’s Toxic Release Inventory (TRI) database and annual slaughter data reported in company or industry reports to evaluate total manure waste. This calculation does not include the runoff from producing the vast quantities of corn and soy feed used to raise livestock and poultry. The companies were chosen as those representing 2/3 or more of the poultry, pork, and beef markets. Given irregularly reported company data to the EPA’s TRI, the calculations represent the average per facility data reported to EPA’s TRI database within the most recent 5-year period from 2012-2017, while manure calculations rely on most recent 2018 livestock and poultry processing figures from company or industry reports, and NRCS estimated animal waste characteristics. The facilities were overlaid with the 2019 NOAA flood risk map identifying regions with a >50% likelihood of minor, moderate, and severe flooding. Facility locations were identified using a combination of EPA TRI release data using NAICS codes for food and agricultural manufacturing, USDA data, and company websites.