Comment submitted by Daryl Maas, Farm Power Northwest LLC

My company develops, owns and operates multi-farm anaerobic manure digesters in Washington State. Like nearly all other on-farm digesters, we use internal combustion engines to burn the digester's methane to generate electricity and capture waste heat for reuse in the digester. While I support the change to SO2 requirements for turbines running on biogas, a similar change to the requirments for internal combustion engines is needed. Turbines are nice for high-end uses which are still mostly experimental with biogas, but almost 100% of farmers with manure digesters use ICE to burn their biogas. The EPA's own Agstar program lists over 100 agriculture digester in operation with the vast majority producing electrcity through ICE.(http://www.epa.gov/agstar/operational.html) Our company has been through the New Source Review process and we can safely say that a relaxation of SO2 standards for ICE would have an immediate and significant impact on farmers' willingness to adopt anaerobic digestion technologies and hence reduce greenhouse gas emissions while generating renewable energy. As it is, the NSR SO2 standards for ICE on farms are a major deterrent to innovation for real-world use of biogas. I would also appreciate it if someone from EPA or elsewhere could contact me about this question since it is nearly impossible to reach the right person on these issues. Thanks. Daryl Maas. 360-424-4519. Daryl@farmpower.com