This proposed project is for the experimental operation and performance review of a pilot-scale anaerobic digester and effluent treatment system for small dairy farms. This would be one of the first digesters built on a dairy farm with a herd size of 50-100 heads. Although digesters are considered to be a valuable addition to a farms manure management strategy, several sources have stated that farms of this size are incapable of feasibly maintaining anaerobic digesters. The principal barrier to implementation of anaerobic digesters is generally considered to be the cost of project-specific engineering and large-scale construction. The digester in development by Avatar Alternative Energy addresses these concerns with the following design features: The digester is modular and can be assembled by a small crew utilizing farm equipment. The digester is a moveable asset on the farm, replacing poured concrete vessels for larger-diameter fiberglass pipe sections, which can be disassembled for maintenance and/or relocation on the farm or resale. Due to the modular nature of the equipment, the scale of the digester can follow changes to the farm¿s herd size. Avatar¿s pilot digester is based on the robust plug flow architecture and includes specific design features to enable inexpensive maintenance and straightforward operation. Avatar also has developed a low-cost solids separator to separate the digested manure into liquid and solid fractions. The manure is treated through a series of steps that will significantly reduce nitrogen and phosphorus and will ultimately be used to support greenhouse activities
