An effort by several environmental groups to tighten regulations on concentrated animal feeding operations (CAFOs) ended as the Ninth Circuit Court of Appeals rejected the petition.

Led by Food and Water Watch and the Center for Biological Diversity, the groups sued the EPA for rejecting a 2017 petition. They claimed the agency’s decision was “arbitrary and capricious.” However, the Ninth Circuit Court ruled that the EPA acted within its legal bounds.

The EPA acknowledged CAFO-related water pollution and opted to study effluent guidelines and consult stakeholders instead of immediately revising regulations.

Agriculture groups intervened in support of the EPA. They argued that many CAFOs are already held to strict standards and that runoff is only exempt when manure is applied using sound practices.

The environmental groups proposed requiring more CAFOs to obtain discharge permits and revising the interpretation of “agricultural stormwater” exemptions. The EPA had previously required permits for potential discharges. A 2011 court ruling limited that authority.

In 2023, EPA began studying CAFO pollution further after rejecting both the 2017 and 2022 petitions from advocacy groups.

Read more on the Ninth Court of Appeals Ruling on concentrated animal feeding operations here.