California dairy farmers are adopting vermifiltration, a method using earthworms to process manure and reduce pollution. Anthony Agueda of Alberto Dairy employs this system, developed by Bio Filtro, which uses large biofilters of wood chips and river rock to process hundreds of thousands of gallons of cow waste daily. This approach aims to cut methane, nitrous oxide, and water contamination, presenting a simpler and more affordable alternative to high-tech solutions like anaerobic digesters.

Manure management contributes significantly to livestock's environmental impact, accounting for 1.6% of US greenhouse gas emissions. Traditional lagoon storage creates methane-producing conditions. Potent greenhouse gases like methane and nitrous oxide, along with nitrates and pathogens, pose risks to air and water quality. California, facing pressure to reduce its dairy sector's methane output, has implemented programs, including one that has allocated over $1 billion to farms for cleaner practices. The state aims to cut methane emissions by 40% below 2013 levels by 2030.

While anaerobic digesters are widely used, they are only economically feasible for larger operations (around 2,000 cattle or more) and do not fully address water pollution. Vermifiltration, in contrast, is seen as a more accessible solution for a broader range of farms, offering a practical way to manage waste and comply with tightening environmental regulations. Further research is ongoing to determine the long-term effectiveness and trade-offs of various manure treatment methods under real-world farm conditions.