Under the Clean Water Act, EPA is required to annually review, and if necessary, strengthen, industry-wide pollution standards—called effluent limitation guidelines—for factory farms, or concentrated animal feeding operations (CAFOs). These guidelines are supposed to ensure that CAFOs are using the best available technology and management practices to reduce their water pollution.

For years, EPA has maintained incredibly lax pollution standards for factory farms, despite mounting evidence that the current guidelines, last updated in 2008, fail to protect waterways. This case, filed in the federal Ninth Circuit Court of Appeals, challenged EPA’s January 2021 decision to maintain the status quo and keep the inadequate guidelines as-is. The agency’s decision was based on a so-called “review” of CAFO pollution, but its cursory analysis focused on incomplete data which failed to capture the full scope of the industry’s polluting impacts.

Across the country, thousands of CAFOs produce vast quantities of manure containing pollutants like E. coli, nitrogen, phosphorus, pharmaceuticals, and heavy metals, which threaten public health and ecosystems when discharged into waterways. EPA itself has established that agricultural activities, including CAFOs, are one of the “leading known sources” of surface water pollution in the United States. Yet EPA’s current CAFO guidelines sanction manure storage and disposal practices that simply exacerbate the problem. For instance, CAFO operators are allowed to store millions of gallons of liquid manure in structures that are designed to—and often do—leak. And once those manure pits are full, EPA allows operators to apply this waste to fields in ways, and at quantities, that are known to harm water quality.

Leaving these outdated, unprotective factory farm pollution guidelines on the books violates the Clean Water Act and EPA’s review and revision obligations. Our lawsuit asked the court to require EPA to reconsider its untenable position and potentially adopt more stringent national standards that better protect our nation’s waterways.
After we filed suit, EPA asked the court for a remand to reevaluate its decision in light of the evidence we presented regarding the inadequacy of its CAFO pollution standards and the flaws in the agency’s review process. The court agreed, and in January 2023, the agency announced a plan to undertake detailed study of factory farm water pollution to determine whether and how to strengthen its Clean Water Act regulation of the industry.

EPA recognized that the factory farm pollution data it had been relying on to determine whether its regulations were effective were “sparse” and inadequate. The agency plans to gather detailed information about factory farm wastewater discharges to rectify this data gap. EPA also admitted to lacking sufficient understanding of pollution control technologies and practices that may have developed since its most recent changes to the CAFO regulations, back in 2003 and 2008. It has therefore agreed to engage in a comprehensive technology review.

If it does its job properly, EPA will soon realize what communities living near factory farms have known for years: EPA has allowed factory farms to pollute egregiously as a matter of course, and it must take immediate action to strengthen its regulation of this polluting industry.