Biogas methane digester is a wastewater and solids treatment
technology. When used on a farm, it processes animal waste
under anaerobic conditions, yielding methane gas and reducing
the volume of solids and treated liquids. The methane can
be sold or used to generate electricity on the farm; the solid
matter left behind is a valuable soil amendment; and the liquids
become an easily applied fertilizer with plant available nutrients
and low pathogen levels. Sustainable Conservation's Methane
Digesters initiative provides technical assistance to farmers
preparing to implement digesters.
If all 65 billion pounds of manure that are created yearly
in California underwent methane digestion, the fertility and
productivity of farm soils would be greatly enhanced, while
supplying an estimated 200+ megawatts of power.
Digester technology could also significantly reduce the pathogens
in dairy waste and help prevent polluted runoff. Additionally,
methane, a powerful greenhouse gas, would be destroyed and
air pollution from dairy liquids substantially mitigated.
Air pollution is a significant problem in California's Central
Valley, one of the worst non–attainment (any area that
does not meet national primary or secondary air quality standards)
areas of the country. By providing a substantial new source
of revenue to the dairy producers, there is a strong economic
incentive to install and utilize environmentally friendly
Digester technology is mostly unfamiliar to dairy producers.
As a result, the technology is unlikely to be adopted without
an incentive program that helps progressive dairies build
and operate these systems, and demonstrate their utility for
other commercial dairies to see. Sustainable Conservation
has championed such a program orchestrating California Energy
Commission's $15 million matching grant program. It is an
important step necessary to demonstrate the viability of the
technology on working dairy farms. So far, 32 dairies have
applied for a grant; they are typically the more progressive
dairies in their area and will be closely watched by their
neighbours. If done right, this investment could radically
alter the agricultural landscape, marrying environmental,
economic, and renewable energy benefits.