Methane Digesters Help Cut Dairy Emissions in California

Study Shows Digesters Reduce Methane By 80 Percent on Farms

A major dairy farm in California’s San Joaquin Valley has demonstrated how methane emissions can be cut through the use of digester technology.

A study from the University of California confirms these systems can reduce methane by about 80 percent.

The digester system works by covering manure lagoons with gas-tight tarps that trap methane gas as it forms. The gas is then processed and used as clean energy, replacing diesel fuel in some transport systems.

The study was conducted over two years, with researchers tracking emissions before and after the digester’s 2021 installation. Early leaks were identified and resolved, showing significant improvements in the system’s performance.

“This was a textbook case of adaptive management,” the researchers noted.

These efforts support California’s push to reduce methane emissions by 40 percent compared to 2013 levels by the end of the decade.

Over 130 digesters now operate across the state, but this is one of the first studies to rigorously confirm their real-world effectiveness.

Despite their success, digesters do not solve all environmental challenges. Other pollutants like ammonia still need to be addressed.

Moreover, setting up a digester system requires considerable investment and long-term upkeep, which may not work for every farm.

To further monitor emissions, California is also using satellite technology to detect large methane leaks from space and take corrective actions.

The successful project reflects how farmers, scientists, and industry leaders can collaborate to produce measurable environmental benefits through innovation and shared commitment.