ANAEROBIC DIGESTER SURVEY OF CALIFORNIA DAIRY PRODUCERS

We conducted a survey to identify for the US Environmental Protection Agency examples of and reasons for the failure of many previously inst alled methane recovery systems. Six dairy producers participated in th is survey. Installation costs of systems ranged from $100,000 to $950, 000. Three producers have continued their dairy operations but no long er use methane recovery technology. Two producers were favorable to th e technology but no longer operate a dairy. Of those surveyed, only on e producer continues to use methane recovery technology. Identified pr oblems associated with unsuccessful operations included poor design, c ollection of manure in a wet form, and incomplete cooperation from ele ctric companies. Producers found that the technology required intense management and was economically risky. Increased cooperation between e lectric companies and small producers of electricity and greater price s paid for electricity might provide positive economic incentives that would encourage methane recovery and electricity generation. One prod ucer indicated that the benefits from anaerobic digester technology to be emphasized to potential users were income from sales of final soli ds and the nutrient value of both solid and liquid effluent streams as fertilizer sources.