The Environmental Protection Agency's AgStar program provides an online directory of on-farm biogas recovery systems. The directory lists equipment manufacturers and distributors; consultants, project developers, and other service providers; and financing and information sources.

The AgStar Web site, http://www.epa.gov/agstar/, provides many other resources, ranging from the basic information on digester systems to reports on specific digester designs, including some using dairy manure feedstocks. It also includes a database of funding sources. Those considering constructing a system can provide a basic site description via an online form as the basis for a follow-up discussion of project feasibility.

To download the directory, go to: http://tinyurl.com/4r7xjh2