Ten Million Tons of Manure In California Are Unaccounted for: New Report

"Stanford researchers found serious loopholes in factory farm regulation — and it’s not just in California."

"Factory farms in California routinely avoid pollution regulations intended to protect the state’s water, finds a new white paper out of Stanford.

Ten million tons of animal manure in the Golden State are unaccounted for, the report finds, thanks to a combination of non-compliance, non-enforcement and opaque disclosure rules. It is not known from public information where the manure went, says Zoe Robertson, JD candidate at Stanford Law and an author of the white paper, but some may well have ended up directly or indirectly in lakes, streams and other public waters.

Lax regulation of factory farm pollution in the United States isn’t unique to California. Factory farms, also known as concentrated animal feeding operations (CAFOs), produce enormous amounts of pollution, yet federal laws to reduce it are limited in scope and riddled with loopholes. Even in states with ostensibly stricter regulatory regimes, like California, CAFO pollution frequently goes unchecked and unregulated.

“California has some of the most factory farms in the country of any state, but it’s really not part of our primary identity,” Lewis Bernier, lead researcher at the Factory Farm Watch project, tells Sentient."

Seth Millstein reports for Sentient March 12, 2026, co-published with ProPublica.

Source: Sentient, 03/18/2026